SerialPortMultiplexer/Socket.cpp

#include "Socket.h"


#include <sys/types.h>       // For data types
#include <sys/socket.h>      // For socket(), connect(), send(), and recv()
#include <netdb.h>           // For gethostbyname()
#include <arpa/inet.h>       // For inet_addr()
#include <unistd.h>          // For close()
#include <netinet/in.h>      // For sockaddr_in
#include <netinet/tcp.h>     // TCP_KEEPCNT
#include <fcntl.h>
typedef void raw_type;       // Type used for raw data on this platform

#include <errno.h>             // For errno

using namespace std;

// SocketException Code

SocketException::SocketException(const string &message, bool inclSysMsg)
	: userMessage(message)
{
	if (inclSysMsg)
	{
		userMessage.append(": ");
		userMessage.append(strerror(errno));
	}
}

SocketException::~SocketException() noexcept (true)
{
}

const char *SocketException::what()
{
	return userMessage.c_str();
}

// Function to fill in address structure given an address and port
static void fillAddr(const string &address, unsigned short port,
                     sockaddr_in &addr)
{
	memset(&addr, 0, sizeof(addr));  // Zero out address structure
	addr.sin_family = AF_INET;       // Internet address

	hostent *host;  // Resolve name
	if ((host = gethostbyname(address.c_str())) == NULL)
	{
		// strerror() will not work for gethostbyname() and hstrerror()
		// is supposedly obsolete
		throw SocketException("Failed to resolve name (gethostbyname())");
	}
	addr.sin_addr.s_addr = *((unsigned long *) host->h_addr_list[0]);

	addr.sin_port = htons(port);     // Assign port in network byte order
}

// Socket Code

Socket::Socket(int type, int protocol)
{

	// Make a new socket
	if ((sockDesc = socket(PF_INET, type, protocol)) < 0)
	{
		throw SocketException("Socket creation failed (socket())", true);
	}
}

Socket::Socket(int sockDesc)
{
	this->sockDesc = sockDesc;
}

Socket::~Socket()
{
	close(sockDesc);
	sockDesc = -1;
}

string Socket::getLocalAddress()
{
	sockaddr_in addr;
	unsigned int addr_len = sizeof(addr);

	if (getsockname(sockDesc, (sockaddr *) &addr, (socklen_t *) &addr_len) < 0)
	{
		throw SocketException("Fetch of local address failed (getsockname())", true);
	}
	return inet_ntoa(addr.sin_addr);
}

unsigned short Socket::getLocalPort()
{
	sockaddr_in addr;
	unsigned int addr_len = sizeof(addr);

	if (getsockname(sockDesc, (sockaddr *) &addr, (socklen_t *) &addr_len) < 0)
	{
		throw SocketException("Fetch of local port failed (getsockname())", true);
	}
	return ntohs(addr.sin_port);
}

void Socket::setLocalPort(unsigned short localPort)
{
	// Bind the socket to its port
	sockaddr_in localAddr;
	memset(&localAddr, 0, sizeof(localAddr));
	localAddr.sin_family = AF_INET;
	localAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	localAddr.sin_port = htons(localPort);

	if (bind(sockDesc, (sockaddr *) &localAddr, sizeof(sockaddr_in)) < 0)
	{
		throw SocketException("Set of local port failed (bind())", true);
	}
}

void Socket::setLocalAddressAndPort(const string &localAddress,
                                    unsigned short localPort)
{
	// Get the address of the requested host
	sockaddr_in localAddr;
	fillAddr(localAddress, localPort, localAddr);

	if (bind(sockDesc, (sockaddr *) &localAddr, sizeof(sockaddr_in)) < 0)
	{
		throw SocketException("Set of local address and port failed (bind())", true);
	}
}

void Socket::setKeepalive()
{
	int optval = 1;
	setsockopt(sockDesc, SOL_SOCKET, SO_KEEPALIVE,&optval, sizeof(optval));

	optval = 2;
	setsockopt(sockDesc, SOL_SOCKET, TCP_KEEPCNT, &optval, sizeof(optval));

	optval = 10;
	setsockopt(sockDesc, SOL_SOCKET, TCP_KEEPIDLE, &optval, sizeof(optval));

	optval = 5;
	setsockopt(sockDesc, SOL_SOCKET, TCP_KEEPINTVL, &optval, sizeof(optval));
}

void Socket::setBlocking(bool flag)
{
	int flags = fcntl(sockDesc, F_GETFL, 0);
	if( !flag )
		flags = flags | O_NONBLOCK;
	else
		flags = flags & ~O_NONBLOCK;
	fcntl(sockDesc, F_SETFL, flags);
}

void Socket::cleanUp()
{

}

int Socket::getFD()
{
	return sockDesc;
}

unsigned short Socket::resolveService(const string &service,
                                      const string &protocol)
{
	struct servent *serv;        /* Structure containing service information */

	if ((serv = getservbyname(service.c_str(), protocol.c_str())) == NULL)
		return atoi(service.c_str());  /* Service is port number */
	else
		return ntohs(serv->s_port);    /* Found port (network byte order) by name */
}

// CommunicatingSocket Code

CommunicatingSocket::CommunicatingSocket(int type, int protocol)
	: Socket(type, protocol)
{
}

CommunicatingSocket::CommunicatingSocket(int newConnSD) : Socket(newConnSD)
{
}

void CommunicatingSocket::connect(const string &foreignAddress,
                                  unsigned short foreignPort)
{
	// Get the address of the requested host
	sockaddr_in destAddr;
	fillAddr(foreignAddress, foreignPort, destAddr);

	// Try to connect to the given port
	if (::connect(sockDesc, (sockaddr *) &destAddr, sizeof(destAddr)) < 0)
	{
		throw SocketException("Connect failed (connect())", true);
	}
}

void CommunicatingSocket::send(const void *buffer, int bufferLen)
{
	if (::send(sockDesc, (raw_type *) buffer, bufferLen, 0) < 0)
	{
		throw SocketException("Send failed (send())", true);
	}
}

int CommunicatingSocket::recv(void *buffer, int bufferLen)
{
	int rtn;
	if ((rtn = ::recv(sockDesc, (raw_type *) buffer, bufferLen, MSG_DONTWAIT)) < 0 )
	{
		if(errno == EWOULDBLOCK || errno == EAGAIN)
			return -1;
		else
			throw SocketException("Received failed (recv())", true);
	}

	return rtn;
}

string CommunicatingSocket::getForeignAddress()
{
	sockaddr_in addr;
	unsigned int addr_len = sizeof(addr);

	if (getpeername(sockDesc, (sockaddr *) &addr,(socklen_t *) &addr_len) < 0)
	{
		throw SocketException("Fetch of foreign address failed (getpeername())", true);
	}
	return inet_ntoa(addr.sin_addr);
}

unsigned short CommunicatingSocket::getForeignPort()
{
	sockaddr_in addr;
	unsigned int addr_len = sizeof(addr);

	if (getpeername(sockDesc, (sockaddr *) &addr, (socklen_t *) &addr_len) < 0)
	{
		throw SocketException("Fetch of foreign port failed (getpeername())", true);
	}
	return ntohs(addr.sin_port);
}

// TCPSocket Code

TCPSocket::TCPSocket()
	: CommunicatingSocket(SOCK_STREAM,
	                      IPPROTO_TCP)
{
}

TCPSocket::TCPSocket(const string &foreignAddress, unsigned short foreignPort, bool keepalive)
	: CommunicatingSocket(SOCK_STREAM, IPPROTO_TCP)
{
	connect(foreignAddress, foreignPort);
	if(keepalive)
		setKeepalive();
}

TCPSocket::TCPSocket(int newConnSD) : CommunicatingSocket(newConnSD)
{
}

// TCPServerSocket Code

TCPServerSocket::TCPServerSocket(unsigned short localPort, int queueLen, bool keepaliveIN)
	: Socket(SOCK_STREAM, IPPROTO_TCP)
{
	keepalive = keepaliveIN;
	setLocalPort(localPort);
	setListen(queueLen);
}

TCPServerSocket::TCPServerSocket(const string &localAddress, unsigned short localPort, int queueLen, bool keepaliveIN)
	: Socket(SOCK_STREAM, IPPROTO_TCP)
{
	keepalive = keepaliveIN;
	setLocalAddressAndPort(localAddress, localPort);
	setListen(queueLen);
}

TCPSocket* TCPServerSocket::accept()
{
	int newConnSD = -1;
	if ((newConnSD = ::accept(sockDesc, NULL, 0)) < 0 && errno != EAGAIN  && errno != EWOULDBLOCK )
	{
		throw SocketException("Accept failed (accept())", true);
	}
	TCPSocket* newSocket = nullptr;
	if(newConnSD > 0)
	{
		newSocket = new TCPSocket(newConnSD);
		if(keepalive)
			newSocket->setKeepalive();
	}
	return newSocket;
}



void TCPServerSocket::setListen(int queueLen)
{
	if (listen(sockDesc, queueLen) < 0)
	{
		throw SocketException("Set listening socket failed (listen())", true);
	}
}

// UDPSocket Code

UDPSocket::UDPSocket()  : CommunicatingSocket(SOCK_DGRAM,
	        IPPROTO_UDP)
{
	setBroadcast();
}

UDPSocket::UDPSocket(unsigned short localPort)   :
	CommunicatingSocket(SOCK_DGRAM, IPPROTO_UDP)
{
	setLocalPort(localPort);
	setBroadcast();
}

UDPSocket::UDPSocket(const string &localAddress, unsigned short localPort)
	: CommunicatingSocket(SOCK_DGRAM, IPPROTO_UDP)
{
	setLocalAddressAndPort(localAddress, localPort);
	setBroadcast();
}

void UDPSocket::setBroadcast()
{
	// If this fails, we'll hear about it when we try to send.  This will allow
	// system that cannot broadcast to continue if they don't plan to broadcast
	int broadcastPermission = 1;
	setsockopt(sockDesc, SOL_SOCKET, SO_BROADCAST,
	           (raw_type *) &broadcastPermission, sizeof(broadcastPermission));
}

void UDPSocket::disconnect()
{
	sockaddr_in nullAddr;
	memset(&nullAddr, 0, sizeof(nullAddr));
	nullAddr.sin_family = AF_UNSPEC;

	// Try to disconnect
	if (::connect(sockDesc, (sockaddr *) &nullAddr, sizeof(nullAddr)) < 0)
	{
		if (errno != EAFNOSUPPORT)
		{
			throw SocketException("Disconnect failed (connect())", true);
		}
	}
}

void UDPSocket::sendTo(const void *buffer, int bufferLen,
                       const string &foreignAddress, unsigned short foreignPort)
{
	sockaddr_in destAddr;
	fillAddr(foreignAddress, foreignPort, destAddr);

	// Write out the whole buffer as a single message.
	if (sendto(sockDesc, (raw_type *) buffer, bufferLen, 0,
	           (sockaddr *) &destAddr, sizeof(destAddr)) != bufferLen)
	{
		throw SocketException("Send failed (sendto())", true);
	}
}

int UDPSocket::recvFrom(void *buffer, int bufferLen, string &sourceAddress,
                        unsigned short &sourcePort)
{
	sockaddr_in clntAddr;
	socklen_t addrLen = sizeof(clntAddr);
	int rtn;
	if ((rtn = recvfrom(sockDesc, (raw_type *) buffer, bufferLen, MSG_DONTWAIT, (sockaddr *) &clntAddr,
	                    (socklen_t *) &addrLen)) < 0)
	{
		throw SocketException("Receive failed (recvfrom())", true);
	}
	sourceAddress = inet_ntoa(clntAddr.sin_addr);
	sourcePort = ntohs(clntAddr.sin_port);

	return rtn;
}

void UDPSocket::setMulticastTTL(unsigned char multicastTTL)
{
	if (setsockopt(sockDesc, IPPROTO_IP, IP_MULTICAST_TTL,
	               (raw_type *) &multicastTTL, sizeof(multicastTTL)) < 0)
	{
		throw SocketException("Multicast TTL set failed (setsockopt())", true);
	}
}

void UDPSocket::joinGroup(const string &multicastGroup)
{
	struct ip_mreq multicastRequest;

	multicastRequest.imr_multiaddr.s_addr = inet_addr(multicastGroup.c_str());
	multicastRequest.imr_interface.s_addr = htonl(INADDR_ANY);
	if (setsockopt(sockDesc, IPPROTO_IP, IP_ADD_MEMBERSHIP,
	               (raw_type *) &multicastRequest,
	               sizeof(multicastRequest)) < 0)
	{
		throw SocketException("Multicast group join failed (setsockopt())", true);
	}
}

void UDPSocket::leaveGroup(const string &multicastGroup)
{
	struct ip_mreq multicastRequest;

	multicastRequest.imr_multiaddr.s_addr = inet_addr(multicastGroup.c_str());
	multicastRequest.imr_interface.s_addr = htonl(INADDR_ANY);
	if (setsockopt(sockDesc, IPPROTO_IP, IP_DROP_MEMBERSHIP,
	               (raw_type *) &multicastRequest,
	               sizeof(multicastRequest)) < 0)
	{
		throw SocketException("Multicast group leave failed (setsockopt())", true);
	}
}