wsksockd.cpp

Go to the documentation of this file.

//----------------------------------------------------------------------------
// ObjectWindows
// Copyright (c) 1995, 1996 by Borland International, All Rights Reserved
//
/// \file
/// Winsock for OWL subsystem.
/// Based on work by Paul Pedriana, 70541.3223@compuserve.com
//----------------------------------------------------------------------------
#include <owl/pch.h>
#include <owl/defs.h>
#include <owl/winsock.h>
 
namespace owl {
 
OWL_DIAGINFO;
 
//
/// Actually 512 is the absolute guaranteed minimum value.  The WSAData
/// structure has the actual value (>=512).
//
int TDatagramSocket::MaxPacketSendSize = 512;
 
//
/// This function does nothing. It relies on TSocket to do all the work.
//
TDatagramSocket::TDatagramSocket()
:
  TSocket()
{
}
 
//
/// This function does nothing. It relies on TSocket to do all the work.
//
TDatagramSocket::TDatagramSocket(SOCKET& src)
:
  TSocket(src)
{
}
 
//
/// This function does nothing. It relies on TSocket to do all the work.
//
TDatagramSocket::TDatagramSocket(TSocketAddress& socketAddress, int addressFormat,
                                 int type, int protocol)
:
  TSocket(socketAddress, addressFormat, type, protocol)
{
}
 
//
/// This function reads the chars into the chData buffer, and removes the data from
/// the queue. chData is a pointer to a destination buffer for the data.
/// nCharsToRead should be set to the maximum desired read size, which needs to be
/// equal or less to the size of chData.
/// The sAddress parameter is filled with the address of the sender. It returns
/// WINSOCK_ERROR if there was an error, WINSOCK_NOERROR otherwise. This Read will
/// get the data from the next buffered packet and delete the packet from memory
/// when finished. Thus if this function is called with a nCharsToRead that is
/// smaller than the next packet, only part of the packet will be read and the rest
/// will be lost.
/// Upon return, nCharsToRead is set to the actual number of characters read. If
/// nCharsToRead returns 0, no data was read. If the function return value is
/// WINSOCK_ERROR, there was a Windows Sockets error. Otherwise, the call was
/// successful, even though no data may have been read.
//
int TDatagramSocket::Read(char* data, int& charsToRead, TSocketAddress& address)
{
  // Simply call recvfrom() and return if some kind of error is encountered.
  //
  int addressSize = sizeof(sockaddr);
  ///PP Need to change this to allow flags.
  int charsReceived = TWinSockDll::recvfrom(Handle, data, charsToRead, 0,
                                              &address, &addressSize);
 
  if (charsReceived == SOCKET_ERROR) {
    // It is entirely possible to get a blocking error here.  For example, a
    //  call to recv() could have been made right after the message was
    //  posted by the driver, but before this notification function got called.
    //
    charsToRead = 0;  // This will be available for the caller to examine.
    LastError = TWinSockDll::WSAGetLastError();
    if (LastError == WSAEWOULDBLOCK)
      return WINSOCK_NOERROR;  // This is not considered an "error" under Winsock.
    // Some other error occurred, return from this function.
    //
    return WINSOCK_ERROR;
  }
  charsToRead = charsReceived;
  return WINSOCK_NOERROR;
}
 
//
/// This function puts the data in the queue and attempts to write the first item in
/// the queue. At the end of the function, an attempt to write the queue is made. If
/// it fails, the data is sent later, after the system has given notification that
/// it is ready. This function returns WINSOCK_ERROR or WINSOCK_NOERROR.
//
int TDatagramSocket::Write(char* data, int& charsToWrite, TSocketAddress& outSocketAddress,
                           bool /*becomeOwnerOfData*/, bool /*copyData*/)
{
  // Note that bBecomeOwnerOfdata and bCopyData are ignored if we are using DataQueues.
  // Note that thus function may block here if blocking is enabled.
  //
  ///PP need to enable flags use.
  int charsSent = TWinSockDll::sendto(Handle, data, charsToWrite, 0,
                                   &outSocketAddress, sizeof(sockaddr));
  if (charsSent == SOCKET_ERROR) {
    //It is entirely possible to get a blocking error here.  For example, a call to
    //  send() could have been made right after the message was posted by the driver,
    //  but before this notification function got called.
    //
    charsToWrite = 0;
    LastError = TWinSockDll::WSAGetLastError();
    if (LastError == WSAEWOULDBLOCK)
      return WINSOCK_NOERROR;
    return WINSOCK_ERROR;
  }
  charsToWrite = charsSent;
  return WINSOCK_NOERROR;
}
 
//
/// Simply calls the other Write() function with the latest address. Arguments and
/// return values are the same.
//
int TDatagramSocket::Write(char* data, int& charsToWrite, bool becomeOwnerOfData, bool copyData)
{
  return Write(data, charsToWrite, PeerSocketAddress, becomeOwnerOfData, copyData);
}
 
//
/// This function is called whenever the socket receives a read notification. This
/// means that data on the port is ready to be read. This function doesn't do much
/// with the error parameter. It simply doesn't do the read if there is an error
/// value. According to Winsock documentation, this error may be "any error in winsock.h".
//
int TDatagramSocket::DoReadNotification(const SOCKET& /*socket*/, int error)
{
  if (error) {
    LastError = error; // TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
 
  // This function dan't do anything on its own without data queues.  Without
  //  DataQueues, you can do two things:  1) subclass TDatagramSocket and write
  //  your own DoReadNotification() or 2) Have the socket redirect the FD_READ
  //  notification to the window of your choice with Socket::SetNotificationSet()
  //  and SetNotificationWindow().
  //
  return WINSOCK_NOERROR;
}
 
//
/// This function is called whenever the socket receives a write notification.
//
int TDatagramSocket::DoWriteNotification(const SOCKET& /*s*/, int error)
{
  if (error) {
    LastError = error; // TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
 
  // This function dan't do anything on its own without data queues.  Without
  //  DataQueues, you can do two things:  1) subclass TDatagramSocket and write
  //  your own DoWriteNotification() or 2) Have the socket redirect the FD_WRITE
  //  notification to the window of your choice with Socket::SetNotificationSet()
  //  and SetNotificationWindow().
  //
  return WINSOCK_NOERROR;
}
 
//----------------------------------------------------------------------------
 
//
/// This function calls TSocket constructor and initializes the state of the
/// connection to not connected.
//
TStreamSocket::TStreamSocket()
:
  TSocket(),
  ConnectStatus(NotConnected)
{
}
 
//
/// This function is an alias constructor.
//
TStreamSocket::TStreamSocket(SOCKET& src)
:
  TSocket(src)
{
  ///!PP Important:  Unless there is a way I haven't found yet, you can't tell
  //  what the ConnectStatus is, given just a SOCKET descriptor.
  // Needs to be set somehow:
  // nConnectStatus = ???;
}
 
//
// Constructor for a protocol defined by an int.
//
TStreamSocket::TStreamSocket(TSocketAddress& socketAddress, int addressFormat, int type, int protocol)
:
  TSocket(socketAddress, addressFormat, type, protocol),
  ConnectStatus(NotConnected)
{
}
 
//
/// This function copies the socket connection information.
//
TStreamSocket& TStreamSocket::operator =(TStreamSocket& src) // !CQ const?
{
  TSocket::operator =(src);
  return *this;
}
 
//
/// This reads from the already received and queued data. This data has already been
/// received from the socket driver.
//
int TStreamSocket::Read(char* data, int& charsToRead)
{
  // Try to receive the characters.
  //
  int charsReceived = TWinSockDll::recv(Handle, data, charsToRead, 0); ///PP I Need to allow the use of flags here.
  if (charsReceived == SOCKET_ERROR) {
    // It is entirely possible to get a blocking error here.  For example, a call to
    //  recv() could have been made right after the message was posted by the driver,
    //  but before this notification function got called.
    //
    charsToRead = 0; // This will be available for the caller to examine.
    LastError = TWinSockDll::WSAGetLastError();
    if (LastError == WSAEWOULDBLOCK)
      return WINSOCK_NOERROR;
    // Some other error occurred.
    //
    return WINSOCK_ERROR;
  }
  charsToRead = charsReceived;
  return WINSOCK_NOERROR;
}
 
//
/// This function writes the buffer into the stream.
//
int TStreamSocket::Write(char* data, int& charsToWrite, int flags,
                bool /*becomeOwnerOfData*/, bool /*copyData*/)
{
  int charsSent = TWinSockDll::send(Handle, data, charsToWrite, flags);
  if (charsSent == SOCKET_ERROR) {
    // It is entirely possible to get a blocking error here.  For example, a call to
    //  send() could have been made right after the message was posted by the driver,
    //  but before this notification function got called.
    //
    charsToWrite = 0;
    LastError = TWinSockDll::WSAGetLastError();
    if (LastError == WSAEWOULDBLOCK) {
      return WINSOCK_NOERROR;
    }
    return WINSOCK_ERROR;
  }
  charsToWrite = charsSent;
  return WINSOCK_NOERROR;
}
 
//
/// This function works just like the Read() function, but it works on the OOB
/// queue.
//
int TStreamSocket::ReadOOB(char* data, int& charsToRead)
{
  // Try to receive the characters.
  ///PP I Need to allow the use of flags here.
  //
  int charsReceived = TWinSockDll::recv(Handle, data, charsToRead, MSG_OOB);
  if (charsReceived == SOCKET_ERROR) {
    // It is entirely possible to get a blocking error here.  For example, a call to
    //  recv() could have been made right after the message was posted by the driver,
    //  but before this notification function got called.
    //
    charsToRead = 0;
    LastError = TWinSockDll::WSAGetLastError();
    if (LastError == WSAEWOULDBLOCK)
      return WINSOCK_NOERROR;
    // Some other error occurred.
    return WINSOCK_ERROR;
  }
  charsToRead = charsReceived;
  return WINSOCK_NOERROR;
}
 
//
/// Works just like TStreamSocket::Write(), except it adds in the MSG_OOB into the
/// flags.
///
/// Perform write operation using out-of-band data (i.e. via a logically
/// independent tranmission channel between the connected sockets).
/// \note For 'non urgent data', you may used TStreamSocket::Write() instead.
//
int TStreamSocket::WriteOOB(char* data, int& charsToWrite, int flags,
                            bool /*becomeOwnerOfData*/, bool /*copyData*/)
{
  flags |= MSG_OOB;
  int charsSent = TWinSockDll::send(Handle, data, charsToWrite, flags);
  if (charsSent == SOCKET_ERROR) {
    // It is entirely possible to get a blocking error here.  For example, a call to
    //  send() could have been made right after the message was posted by the driver,
    //  but before this notification function got called.
    //
    charsToWrite = 0;
    LastError = TWinSockDll::WSAGetLastError();
    if (LastError == WSAEWOULDBLOCK) {
      return WINSOCK_NOERROR;
    }
    return WINSOCK_ERROR;
  }
  charsToWrite = charsSent;
  return WINSOCK_NOERROR;
}
 
//
/// This function puts this socket into a passive "listening" mode.
//
int TStreamSocket::Listen(int maxQueuedConnections)
{
  if (TWinSockDll::listen(Handle, maxQueuedConnections)) {
    LastError = TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
  ConnectStatus = Listening;
  return WINSOCK_NOERROR;
}
 
//
/// This function sets myPeerSocketAddress to sAddressToConnectTo then calls
/// Connect(). (See Connect() for more details.)
//
int TStreamSocket::Connect(TSocketAddress& addressToConnectTo)
{
  SetPeerSocketAddress(addressToConnectTo);
  return Connect();
}
 
//
/// This function uses myPeerSocketAddress, which needs to be set before calling
/// this function. The connection attempt (and this function) should return right
/// away, without blocking. When actually connected, a notification comes from the
/// driver at the DoConnectNotification() function. Upon receiving that
/// notification, the nConnectStatus is set to nConnected. Technically, a datagram
/// socket can call connect; doing this sets the default address for future
/// send()/recv() calls that the datagram socket might use. It's in the
/// TStreamSocket class for simplicity, and because the TDatagramSocket class
/// already supports its own default address system.
//
int TStreamSocket::Connect()
{
  if (TWinSockDll::connect(Handle, &PeerSocketAddress, sizeof(sockaddr))) {
    LastError = TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
  // The following code assumes that the socket is in non-blocking mode.  If the socket was in
  //  blocking mode, then nConnectStatus would be nConnected.  Thus, this code is slightly
  //  bugged and can be patched with a call to select() to determine whether the socket is
  //  really connected or not.  Looked at another way, a blocking socket can be said to be
  //  connected if nConnectStatus is either nConnected or nConnectPending.
  //
  ConnectStatus = ConnectPending;
  return WINSOCK_NOERROR;
}
 
//
/// This function will try to accept a connection with the first connecting peer
/// that is waiting in the queue. If successful, the TStreamSocket& socket will have
/// a valid and connected socket, a proper status of nConnected, and the correct
/// peer socket address. The caller usually calls this function in response to an
/// Accept notification. The caller merely needs to create a new TStreamSocket and
/// pass it to this function. The default constructor for TStreamSocket can be used,
/// because this function fixes up the missing parts.
//
int TStreamSocket::Accept(TStreamSocket& socket)
{
  if (Accept(socket.Handle, socket.PeerSocketAddress) == WINSOCK_NOERROR) {
    socket.ConnectStatus = Connected;
    socket.SetSocketStyle(Family, Type, Protocol); //Copy our Family, etc. just to make sure.
    return WINSOCK_NOERROR;
  }
  return WINSOCK_ERROR;
}
 
//
/// This function tries to accept a connection with the first connecting peer that
/// is waiting in the queue. If successful, the socket reference argument is set to
/// a new connected socket. The sAddress reference argument is set to the address of
/// the connecting peer. The caller of this function may immediately use the new
/// socket with data sends, etc.
///
/// Note that the caller may want to flag the socket as connected. If the socket
/// belongs to a StreamSocket, its nConnectionStatus can be set as nConnected. The
/// return value is either WINSOCK_ERROR or WINSOCK_NOERROR. If there is an error,
/// then nLastError will be set with the appropriate error.
///
/// Note that this call could be made when no pending socket connections are in the
/// queue. If this is the case, the call will block if the socket is marked as
/// blocking, and will return WINSOCK_ERROR with WSAEWOULDBLOCK if the socket is
/// marked as non-blocking. This function is usually called in response to an accept
/// notification. A socket is set up as a stream socket and listen() is called. When
/// a connection is ready, the driver notifies the listening socket with a
/// DoAcceptNotification() call. (See the DoAcceptNotification() call
/// documentation.) This Accept() function should be called as a result.
//
int TStreamSocket::Accept(SOCKET& socket, sockaddr& address)
{
  int addressLength = sizeof(sockaddr);
  socket = TWinSockDll::accept(Handle, &address, &addressLength);
 
  if (socket == static_cast<SOCKET>(INVALID_SOCKET)) {
    LastError = TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
  return WINSOCK_NOERROR;
}
 
//
/// This function is called when the socket receives a read notification unless
/// there is an error. This means that data on the port is ready to be read.
/// This function doesn't do much with the nError parameter. It doesn't do the read
/// if there is an error value.
//
int TStreamSocket::DoReadNotification(const SOCKET& /*socket*/, int error)
{
  if (error) {
    LastError = error; // TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
  return WINSOCK_NOERROR;
}
 
//
/// This function is called when the socket receives a write notification. This
/// means that data on the port is ready to be written.
//
int TStreamSocket::DoWriteNotification(const SOCKET& /*s*/, int error)
{
  if (error) {
    LastError = error;  ///PP TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
 
  // This function dan't do anything on its own without data queues.  Without
  //  DataQueues, you can do two things:  1) subclass TStreamSocket and write
  //  your own DoWriteNotification() or 2) Have the socket redirect the FD_WRITE
  //  notification to the window of your choice with Socket::SetNotificationSet()
  //  and SetNotificationWindow().
  //
  return WINSOCK_NOERROR;
}
 
//
/// This notification appears when OOB data is ready to be received on the socket
/// port.
//
int TStreamSocket::DoOOBNotification(const SOCKET& /*s*/, int error)
{
  if (error) {
    LastError = error; // TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
 
  // This function dan't do anything on its own without data queues.  Without
  //  DataQueues, you can do two things:  1) subclass TStreamSocket and write
  //  your own DoOOBNotification() or 2) Have the socket redirect the FD_OOB
  //  notification to the window of your choice with Socket::SetNotificationSet()
  //  and SetNotificationWindow().
  //
  return WINSOCK_NOERROR;
}
 
//
/// This notification occurs when a client socket on the network is attempting to
/// connect to you. Code needs to be written to intercept this notification.
//
int TStreamSocket::DoAcceptNotification(const SOCKET& /*s*/, int /*error*/)
{
  return 0; // We don't do anything.  We let the pending acceptance sit there.
}
 
//
/// This means that the connection attempted with a server on the network has
/// completed. This function gets called sometime after this object makes a
/// connect() attempt. If the connect attempt was non-blocking, a notification is
/// posted. When this function gets called, the nConnectStatus should be
/// nConnecting.
//
int TStreamSocket::DoConnectNotification(const SOCKET& /*s*/, int error)
{
  if (error) {
    // There was an error, and we cannot connect; this may due to a number of reasons.
    // We turn off our 'nConnectStatus' to 'nNotConnected'.  This is becuase our attempt
    //  to connect failed.
    //
    ConnectStatus = NotConnected;
    LastError = error;   ///PP TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
  ConnectStatus = Connected;
  return WINSOCK_NOERROR;
}
 
//
/// This notification gets called when the socket has been closed. The socket is
/// marked as not connected, so the user can find out about it. It is important to
/// read any data that may be waiting in the queue before changing the status of the
/// connection and doing any notification.
//
int TStreamSocket::DoCloseNotification(const SOCKET& /*s*/, int error)
{
  if (error) {
    LastError = error;  ///PP TWinSockDll::WSAGetLastError();
    return WINSOCK_ERROR;
  }
  return WINSOCK_NOERROR;
}
 
} // OWL namespace
/* ========================================================================== */