/*
	Simple TCP socket connect test application. on ROS you can run this once.
	Running it twice causes error and BSOD crash saying multiple IRPs were recevied.
	NOTE: cleanup is carried out properly, this appears to be a winsock bug.
*/

#include<stdio.h>
#include<string.h>
#include<unistd.h> /* for sleep() */
#include<winsock2.h>

/* pragma comment(lib,"ws2_32.lib") //Winsock Library */

#define BUFLEN 512	//Max length of buffer
#define PORT 8888	//The port on which to listen for incoming data

int main()
{
	SOCKET st, ct; // server udp, server tcp, client tcp and connection accepted tcp sockets
	struct sockaddr_in server;//, si_other;
	WSADATA wsa;
	char message[BUFLEN];	

	//Initialise winsock
	printf("\nTCP dynamic port Socket connection test app starting.");
	if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
	{
		printf("Winsock init Failed. Error Code : %d",WSAGetLastError());
		exit(EXIT_FAILURE);
	} else
	{
	printf("Winsock Initialized on test App.\n");
	
	//Create a TCP socket
	if((st = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
	{
		printf("Could not create server socket : %d" , WSAGetLastError());
	} else
	printf("TCP server side AF_INET Socket created succesfully.\n");
	
	//Prepare the sockaddr_in structure
	server.sin_family = AF_INET;  //   <<=== BIND TO ALL IP ADDRESSES
	server.sin_addr.s_addr = INADDR_ANY;
	server.sin_port = htons( 8888 ); 
	
	//Bind
	if( bind(st ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
	{
		printf("server socket Bind on INADDR_ANY port 8888 failed with error code : %d" , WSAGetLastError());
		exit(EXIT_FAILURE);
		} else 
		{
			puts("TCP socket Bind INADDR_ANY port 8888 completed succesfully");

			// start TCP socket listening
			if( listen(st ,SOMAXCONN) == SOCKET_ERROR)
			{
				printf("server socket Listen call failed with error code : %d" , WSAGetLastError());
				exit(EXIT_FAILURE);
			}
			puts("TCP socket Listen done, the TCP port should now be visible in netstat");
			puts("(press enter to continue after checking)");

			gets(message);
			// now we create yet another TCP socket but specifying port zero to get a dynamic port number
		
			//Create a TCP socket
			if((ct = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
			{
				printf("Could not create client side socket : %d" , WSAGetLastError());
			} else
			{
				printf("TCP client Socket created.\n");
	
				//Prepare the sockaddr_in structure for client socket
				server.sin_family = AF_INET;
				server.sin_addr.s_addr = inet_addr("127.0.0.1");   // <<=== source is loopback IP address
				server.sin_port = htons( 8889 ); // set to fixed port to see if it changes anything. port zero to get dynamic port assigned.. don't care
	
				//Bind
				if( bind(ct ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
				{
					printf("client socket Bind failed with error code : %d" , WSAGetLastError());
					exit(EXIT_FAILURE);
				}
				puts("TCP client socket Bind completed using dynamic port ");

				//Prepare the target IP sockaddr_in structure
				server.sin_family = AF_INET;
				server.sin_addr.s_addr = inet_addr("127.0.0.1");    // <<=== connect to loopback IP address
				server.sin_port = htons( 8888 ); // connect to our target port which is already listening on first socket
	
				if( connect(ct ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
				{
					printf("client socket Connect failed with error code : %d" , WSAGetLastError());
					exit(EXIT_FAILURE);
				} else 
				{
					puts("TCP client socket Connected successfully. ");
				}
				puts("TCP socket pair created/connected, calling closesocket for both. ");
				puts("closesocket/WSACleanup should free resources so port can be used again. ");
	
				if ( closesocket(ct) )
				{
					printf("client socket closesocket failed with error code : %d" , WSAGetLastError());
					exit(EXIT_FAILURE);
				}
			}
			if ( closesocket(st) )
			{
				printf("server socket closesocket failed with error code : %d" , WSAGetLastError());
				exit(EXIT_FAILURE);
			}

		}
		WSACleanup();
	}	
	puts("Winsock cleanup is completed, check port in netstat(should not be listed)");
	puts("press enter to exit test. Run the application again to see BSOD.");
	gets(message);
	return 0;
}