how to check that socket is active on TCP layer? - c

Question

typedef unsigned int uint16;
SOCKET s, new_socket;
uint16 port =18001;
void CreateSocket()
{
WSADATA wsa;
struct sockaddr_in server; // creating a socket address structure: structure contains ip address and port number
printf("Initializing Winsock\n");
if(WSAStartup(MAKEWORD(2,2), &wsa)!=0)
{
printf("Failed Error Code: %d", WSAGetLastError());
return -1;
}
printf("Initialised\n");
//CREATING a SOCKET
if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
printf("Could not Create Socket\n");
//return 0;
}
printf("Socket Created\n");
server.sin_addr.s_addr = inet_addr("192.168.0.1");
server.sin_family = AF_INET;
server.sin_port = htons(port);
//Binding between the socket and ip address
if(bind (s, (struct sockaddr *) &server, sizeof(server)) == SOCKET_ERROR)
{
printf("Bind failed with error code: %d", WSAGetLastError());
}
puts("Bind Done");
//Listen to incoming connections
listen(s, 3);
//Accepting the incoming connection
new_socket = accept(s, NULL, NULL);
if (new_socket == INVALID_SOCKET)
{
printf(L"accept failed with error: %ld\n", WSAGetLastError());
closesocket(new_socket);
WSACleanup();
return 1;
}
else
printf("Client connected.\n");
closesocket(s);
}
int main()
{
CreateSocket();
return 0;
}
this is for TCP.
I am receiving a connection from the MASTER via the above ip address and port number, So I created a socket with port number and ip address for it. But how to check that the socket is active ?? how to check that the above socket code is valid (it's not showing any error). I am getting an error on the MASTER side saying that :
CONNECT EVENT CHECK FAILED (WSAGetLastError())
Could anyone help me in this ??

Answer 1

There is no connection between your socket and the address, you never bind() the address in server to the socket s.
Which, of course, is why your client fails to connect since the socket will not be using the expected port. I assume that you elsewhere call accept() and so on, to actually make the socket accept incoming connections, too.