Winsock2 server side with random listening port

gistfile1.cpp

WSADATA wsaData;
int iResult;
iResult = WSAStartup(MAKEWORD(2,2),&wsaData);
if (iResult != 0) {
	return;
}
 
SOCKADDR_IN server;
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = 0;
SOCKET sock = INVALID_SOCKET;
sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sock == INVALID_SOCKET) {
	WSACleanup();
	return;
}
iResult = bind(sock, (SOCKADDR*)&server, sizeof server);
if (iResult == SOCKET_ERROR) {
	closesocket(sock);
	WSACleanup();
	return;
}
 
int len = sizeof server;
 
getsockname(sock, (SOCKADDR*)&server, &len);
listen(sock, 1);
int port = htons(server.sin_port);