lpBuffers中的buf数据是什么格式

int WSPSend (
  SOCKET               s,                                                
  LPWSABUF               lpBuffers,                                      
  DWORD               dwBufferCount,                                     
  LPDWORD               lpNumberOfBytesSent,                             
  DWORD               dwFlags,                                           
  LPWSAOVERLAPPED        lpOverlapped,                            
  LPWSAOVERLAPPED_COMPLETION_ROUTINE   lpCompletionRoutine,  
  LPWSATHREADID          lpThreadId,                                
  LPINT               lpErrno                                            
)
中的lpBuffers中的buf数据是什么格式？（包头，哪类协义）
typedef struct __WSABUF {
  u_long      len;
  char FAR    *buf;
} WSABUF, FAR * LPWSABUF;