Thread: Sockets program

I have to send data over the internet and I have a working windows sockets program that does it but after like sending a command about 50 times or so, the link goes bad and I cant send any more data. I think a buffer of some sort is filling up but I dont know how to empty it.


Thank you.

please post what you think is the offending code.

Here is the server side of my sockets program.

Code:

// winsock for our network communication
#include <winsock2.h>
// stdio for I/O
#include <stdio.h>
#include <iostream.h>
#include <time.h>

// -----------------------------------------------------------------------------------
// startupServerForListening() - will return us a socket that is bound to the
// port we specify, and is listening for connections if all operations succeeded,
// and a -1 if startup failed.
int startupServerForListening(unsigned short port);

// -----------------------------------------------------------------------------------
// shutdownServer() - will take the socket we specify and shutdown the 
// network utilities we started with startupServerForListening()
// Note: In order to function properly, the socket passed in MUST be the
// socket created by the startupServerForListening() function
void shutdownServer(int socket);

void main() 
{


	// the socket my server will use for listening
	int serverSocket;

	// startup our server utilities with my handy function
	serverSocket = startupServerForListening(7654);

	// check for errors
	if (serverSocket == -1) 
	{
		printf("Network Startup Failed!\nProgram Terminating\n");
		return;
	}

	// accept a client
	int clientSocket;
	clientSocket = accept(serverSocket, 0, 0);

	// check for errors
	if (clientSocket == SOCKET_ERROR) 
	{
		printf("Accept Failed!\n");
	}

	int nBytes;
	// message size so we will know how much data we will send and receive
	#define MESSAGE_SIZE 2
	char inMessage[MESSAGE_SIZE];
	// receive at MAX sizeof(inMessage) bytes into inMessage from the client using clientSocket
	nBytes = recv(clientSocket, inMessage, sizeof(inMessage), 0);

	// check for errors
	if (nBytes == SOCKET_ERROR) 
	{
		printf("Recv Failed!\n");
	}
	else
	{
		cout<<"Command received"<<endl;
		cout<<"Command is: "<<inMessage<<endl;
		
	}
	//and shutting down our network.
	if (inMessage[MESSAGE_SIZE] = 0)
	{
		// close our client socket
		closesocket(clientSocket);

		// and shutdown our network
		shutdownServer(serverSocket);

		printf("Press any key to continue ...\n");
		getchar();
	}
}

// -----------------------------------------------------------------------------------
// startupServerForListening() - a function to startup winsock, and open a socket for listening

int startupServerForListening(unsigned short port) {

	// the winsock data structure
	WSAData wsaData;

	// startup winsock
	if (WSAStartup(MAKEWORD(2, 2), &wsaData) == SOCKET_ERROR) {
		printf("Could Not Start Up Winsock!\n");
		return -1;
	}

	// create  socket
	int mySocket = socket(AF_INET, SOCK_STREAM, 0);

	// make sure nothing bad happened
	if (mySocket == SOCKET_ERROR) {
		printf("Error Opening Socket!\n");
		return -1;
	}

	// the address structure
	struct sockaddr_in server;

	// fill the address structure with appropriate data
	server.sin_family = AF_INET;
	server.sin_port = htons(port);
	server.sin_addr.s_addr = INADDR_ANY;

	// and now bind my socket
	if (bind(mySocket, (sockaddr*)&server, sizeof(server)) == SOCKET_ERROR) {
		printf("Bind Failed!\n");
		closesocket(mySocket);
		return -1;
	}

	// mark socket for listening
	if (listen(mySocket, 5) == SOCKET_ERROR) {
		printf("Listen Failed!\n");
		closesocket(mySocket);
		return -1;
	}

	printf("Server Started\n");

	return mySocket;
}

// -----------------------------------------------------------------------------------
// shutdownServer() - a function to shutdown a socket and clean up winsock

void shutdownServer(int socket) {
	// close our socket
	closesocket(socket);

	// shut down winsock
	WSACleanup();

	printf("Server Shutdown\n");
}