// -*- C++ -*-

//=============================================================================
/**
 *  @file   SSL_Asynch_Stream.h
 *
 *  SSL_Asynch_Stream.h,v 1.17 2005/12/04 01:57:03 ossama Exp
 *
 *  @author Alexander Libman <alibman@baltimore.com>
 */
//=============================================================================

#ifndef ACE_SSL_ASYNCH_STREAM_H
#define ACE_SSL_ASYNCH_STREAM_H

#include /**/ "ace/pre.h"
#include "SSL_Context.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
#pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#if OPENSSL_VERSION_NUMBER > 0x0090581fL && ((defined (ACE_WIN32) && !defined (ACE_HAS_WINCE)) || (defined (ACE_HAS_AIO_CALLS)))

#include "SSL_Asynch_BIO.h"

#include "ace/Asynch_IO_Impl.h"
#include "ace/Message_Block.h"
#include "ace/Synch_Traits.h"
#include "ace/Thread_Mutex.h"


ACE_BEGIN_VERSIONED_NAMESPACE_DECL

/// Forward declarations
class ACE_SSL_Asynch_Result;
class ACE_SSL_Asynch_Read_Stream_Result;
class ACE_SSL_Asynch_Write_Stream_Result;


// Only provide forward declarations to prevent possible abuse of the
// friend declarations in ACE_SSL_Asynch_Stream.
struct ACE_SSL_Asynch_Stream_Accessor;

/**
 * @class ACE_SSL_Asynch_Stream
 *
 * @brief This class is a factory for starting off asynchronous reads
 * on a stream. This class forwards all methods to its
 * implementation class.
 * @par
 * Once open() is called, multiple asynchronous read()s can
 * started using this class.  An ACE_SSL_Asynch_Stream::Result
 * will be passed back to the @param handler when the asynchronous
 * reads completes through the ACE_Handler::handle_read_stream
 * callback.
 */
class ACE_SSL_Export ACE_SSL_Asynch_Stream
  : public ACE_Asynch_Operation,
    public ACE_Service_Handler
{
public:

  // Use a class/struct to work around scoping
  // problems for extern "C" free functions with some compilers.  For
  // example, some can't handle
  //
  //   friend ::some_extern_c_free_function (...)
  //
  // Note that we could use a straight C++ (i.e. not extern "C") free
  // function, but using a class or struct allows us to hide the
  // interface from the user, which prevents abuse of this friend
  // relationship.
  friend struct ACE_SSL_Asynch_Stream_Accessor;

  enum Stream_Type
    {
      ST_CLIENT = 0x0001,
      ST_SERVER = 0x0002
    };

  /// The constructor.
  /**
   * @param context Pointer to @c ACE_SSL_Context instance containing
   *                the OpenSSL @c SSL data structure to be associated
   *                with this @c ACE_SSL_SOCK_Stream.  The @c SSL data
   *                structure will be copied to make it at least
   *                logically independent of the supplied @a context.
   */
  ACE_SSL_Asynch_Stream (Stream_Type s_type = ST_SERVER,
                         ACE_SSL_Context * context = 0);

  /// Destructor
  virtual ~ACE_SSL_Asynch_Stream (void);

  int cancel(void);

  int close (void);

  int open (ACE_Handler &handler,
            ACE_HANDLE handle = ACE_INVALID_HANDLE,
            const void *completion_key = 0,
            ACE_Proactor *proactor = 0);

  /// NOTE: This method has been specifically put in place so that
  /// compilers like the borland doesnt get confused between the above
  /// open () call with the one in the ACE_Service_Handler, from which
  /// this class is derived from..
  void open (ACE_HANDLE new_handle,
             ACE_Message_Block &message_block);

  int read (ACE_Message_Block &message_block,
            size_t num_bytes_to_read,
            const void *act = 0,
            int priority = 0,
            int signal_number = ACE_SIGRTMIN);

  int write (ACE_Message_Block &message_block,
             size_t bytes_to_write,
             const void *act = 0,
             int priority = 0,
             int signal_number = ACE_SIGRTMIN);

protected:

  /// virtual from ACE_Service_Handler

  /// This method is called when BIO write request is completed. It
  /// processes the IO completion and calls do_SSL_state_machine().
  virtual void handle_write_stream
               (const ACE_Asynch_Write_Stream::Result &result);

  /// This method is called when BIO read request is completed. It
  /// processes the IO completion and calls do_SSL_state_machine().
  virtual void handle_read_stream
               (const ACE_Asynch_Read_Stream::Result &result);

  /// This method is called when all SSL sessions are closed and no
  /// more pending AIOs exist.  It also calls users handle_wakeup().
  virtual void handle_wakeup (void);

  /**
   * @name SSL State Machine
   */
  //@{
  int do_SSL_state_machine (void);
  int do_SSL_handshake (void);
  int do_SSL_read (void);
  int do_SSL_write(void);
  int do_SSL_shutdown(void);
  //@}

  void print_error (int err_ssl,
                    const ACE_TCHAR *pText);

  int pending_BIO_count (void);

  /// This method is called to notify user handler when user's read in
  /// done.
  int notify_read (int bytes_transferred, int error);

  /// This method is called to notify user handler when user's write
  /// in done.
  int notify_write (int bytes_transferred, int error);

  /// This method is called to notify ourself that SSL session is
  /// shutdown and that there is no more I/O activity now and in the
  /// future.
  int notify_close(void);

  /**
   * @name BIO Helpers
   */
  //@{
  int ssl_bio_read (char * buf, size_t len, int & errval);
  int ssl_bio_write (const char * buf, size_t len, int & errval);
  //@}

private:

  // Preventing copying through construction or assignment.
  ACE_SSL_Asynch_Stream (ACE_SSL_Asynch_Stream const &);
  ACE_SSL_Asynch_Stream & operator= (ACE_SSL_Asynch_Stream const &);

protected:

  /// Stream Type ST_CLIENT/ST_SERVER
  Stream_Type type_;

  /// The real file/socket handle
  ACE_HANDLE handle_;

  /// The proactor
  ACE_Proactor * proactor_;

  /// External,i.e user  handler
  ACE_Handler * ext_handler_;

  /// External, i.e. read result faked for user
  ACE_SSL_Asynch_Read_Stream_Result *  ext_read_result_ ;

  /// External, i.e. write result faked for user
  ACE_SSL_Asynch_Write_Stream_Result * ext_write_result_ ;

  /// Stream state/flags
  enum Stream_Flag
    {
      /// istream_ open OK
      SF_STREAM_OPEN    = 0x0001,
      /// request to SSL shutdown
      SF_REQ_SHUTDOWN   = 0x0002,
      /// SSL shutdown finished
      SF_SHUTDOWN_DONE  = 0x0004,
      /// Close notification sent
      SF_CLOSE_NTF_SENT = 0x0008,
      /// Stream can be safely destroyed
      SF_DELETE_ENABLE  = 0x0010
    };

  int flags_;

  /// The SSL session.
  SSL * ssl_;

  /// The BIO implementation
  BIO * bio_;

  /// The real streams which work under the ssl connection.
  /// BIO performs I/O via this streams
  enum BIO_Flag  // internal IO flags
    {
      /// End of stream
      BF_EOS   = 0x01,
      /// Real AIO in progress
      BF_AIO   = 0x02
    };

  /**
   * @name Internal stream, buffer and info for BIO read
   */
  //@{
  ACE_Asynch_Read_Stream  bio_istream_;
  ACE_Message_Block       bio_inp_msg_;
  int                     bio_inp_errno_;
  int                     bio_inp_flag_;
  //@}

  /**
   * @name Internal stream, buffer and info for BIO write
   */
  //@{
  ACE_Asynch_Write_Stream bio_ostream_;
  ACE_Message_Block       bio_out_msg_;
  int                     bio_out_errno_;
  int                     bio_out_flag_;
  //@}

  /// Mutex to protect work
  ACE_SYNCH_MUTEX mutex_;

};

ACE_END_VERSIONED_NAMESPACE_DECL

#endif  /* OPENSSL_VERSION_NUMBER > 0x0090581fL && (ACE_WIN32 ||
           ACE_HAS_AIO_CALLS) */

#include /**/ "ace/post.h"

#endif  /* ACE_SSL_ASYNCH_STREAM_H */
