1 files changed, 569 insertions, 0 deletions
diff --git a/nxcomp/Transport.h b/nxcomp/Transport.h
new file mode 100755
index 000000000..89d2616cb
--- /dev/null
+++ b/nxcomp/Transport.h
@@ -0,0 +1,569 @@
+/**************************************************************************/
+/*                                                                        */
+/* Copyright (c) 2001, 2007 NoMachine, http://www.nomachine.com/.         */
+/*                                                                        */
+/* NXCOMP, NX protocol compression and NX extensions to this software     */
+/* are copyright of NoMachine. Redistribution and use of the present      */
+/* software is allowed according to terms specified in the file LICENSE   */
+/* which comes in the source distribution.                                */
+/*                                                                        */
+/* Check http://www.nomachine.com/licensing.html for applicability.       */
+/*                                                                        */
+/* NX and NoMachine are trademarks of NoMachine S.r.l.                    */
+/*                                                                        */
+/* All rights reserved.                                                   */
+/*                                                                        */
+/**************************************************************************/
+
+#ifndef Transport_H
+#define Transport_H
+
+#include <zlib.h>
+#include <errno.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "Misc.h"
+#include "Control.h"
+
+#include "Types.h"
+#include "Timestamp.h"
+#include "Socket.h"
+
+//
+// Set the verbosity level.
+//
+
+#define PANIC
+#define WARNING
+#undef  TEST
+#undef  DEBUG
+
+//
+// Define this to lock and unlock the
+// memory-to-memory transport buffers
+// before they are accessed. The code
+// is outdated and doesn't work with
+// the current pthread library.
+//
+
+#undef  THREADS
+
+//
+// Define this to know when a socket
+// is created or destroyed.
+//
+
+#undef  REFERENCES
+
+//
+// Size of buffer if not set by user.
+//
+
+#define TRANSPORT_BUFFER_DEFAULT_SIZE         16384
+
+//
+// Type of transport.
+//
+
+typedef enum
+{
+  transport_base,
+  transport_proxy,
+  transport_agent,
+  transport_last_tag
+
+} T_transport_type;
+
+//
+// This class handles the buffered I/O on
+// the network sockets.
+//
+
+//
+// TODO: This class is useful but adds a lot of
+// overhead. There are many improvements we can
+// make here:
+//
+// - There should be a generic Buffer class, ac-
+//   comodating a list of memory buffers. This
+//   would enable the use of the readv() and
+//   writev() functions to perform the I/O on
+//   the socket.
+//
+// - The buffering should be moved to the Write-
+//   Buffer and ReadBuffer classes. By performing
+//   the buffering here and there, we are dupli-
+//   cating a lot of code and are adding a lot
+//   of useless memory copies.
+//
+// - Stream compression should be removed. The
+//   proxy should compress the frames based on
+//   the type and should include the length of
+//   the decompressed data in the header of the
+//   packet. Besides avoiding the compression
+//   of packets that cannot be reduced in size,
+//   we would also save the additional memory
+//   allocations due to the fact that we don't
+//   know the size of the decode buffer at the
+//   time we read the packet from the network.
+//
+// - The other utilities implemented here, like
+//   the functions forcing a write on the socket
+//   or waiting for more data to become available
+//   should be moved to the Proxy or the Channel
+//   classes.
+//
+
+class Transport
+{
+  public:
+
+  //
+  // Member functions.
+  //
+
+  Transport(int fd);
+
+  virtual ~Transport();
+
+  int fd() const
+  {
+    return fd_;
+  }
+
+  T_transport_type getType()
+  {
+    return type_;
+  }
+
+  //
+  // Virtual members redefined by proxy
+  // and 'memory-to-memory' I/O layers.
+  //
+
+  virtual int read(unsigned char *data, unsigned int size);
+
+  virtual int write(T_write type, const unsigned char *data, const unsigned int size);
+
+  virtual int flush();
+
+  virtual int drain(int limit, int timeout);
+
+  virtual void finish()
+  {
+    fullReset();
+
+    finish_ = 1;
+  }
+
+  virtual int length() const
+  {
+    return w_buffer_.length_;
+  }
+
+  virtual int pending() const
+  {
+    return 0;
+  }
+
+  virtual int readable() const
+  {
+    return GetBytesReadable(fd_);
+  }
+
+  virtual int writable() const
+  {
+    return GetBytesWritable(fd_);
+  }
+
+  virtual int queued() const
+  {
+    return GetBytesQueued(fd_);
+  }
+
+  virtual int flushable() const
+  {
+    return 0;
+  }
+
+  virtual int wait(int timeout) const;
+
+  void setSize(unsigned int initialSize,
+                   unsigned int thresholdSize,
+                       unsigned int maximumSize);
+
+  //
+  // Return a pointer to the data
+  // in the read buffer.
+  //
+
+  virtual unsigned int getPending(unsigned char *&data)
+  {
+    data = NULL;
+
+    return 0;
+  }
+
+  virtual void pendingReset()
+  {
+  }
+
+  virtual void partialReset()
+  {
+    partialReset(w_buffer_);
+  }
+
+  virtual void fullReset();
+
+  int blocked() const
+  {
+    return blocked_;
+  }
+
+  protected:
+
+  //
+  // Make room in the buffer to accomodate 
+  // at least size bytes.
+  //
+
+  int resize(T_buffer &buffer, const int &size);
+
+  void partialReset(T_buffer &buffer)
+  {
+    if (buffer.length_ == 0 &&
+            (buffer.data_.size() > initialSize_ ||
+                 buffer.data_.capacity() > initialSize_))
+    {
+      fullReset(buffer);
+    }
+  }
+
+  void fullReset(T_buffer &buffer);
+
+  //
+  // Data members.
+  //
+
+  int fd_;
+
+  int blocked_;
+  int finish_;
+
+  T_buffer w_buffer_;
+
+  unsigned int initialSize_;
+  unsigned int thresholdSize_;
+  unsigned int maximumSize_;
+
+  T_transport_type type_;
+
+  private:
+
+  #ifdef REFERENCES
+
+  static int references_;
+
+  #endif
+};
+
+//
+// This class handles buffered I/O and 
+// compression of the proxy stream.
+//
+
+class ProxyTransport : public Transport
+{
+  public:
+
+  ProxyTransport(int fd);
+
+  virtual ~ProxyTransport();
+
+  virtual int read(unsigned char *data, unsigned int size);
+
+  virtual int write(T_write type, const unsigned char *data, const unsigned int size);
+
+  virtual int flush();
+
+  //
+  // Same as in the base class.
+  //
+  // virtual int drain(int limit, int timeout);
+  //
+  // virtual void finish();
+  //
+
+  //
+  // Same as in the base class.
+  //
+  // virtual int length() const
+  //
+
+  virtual int pending() const
+  {
+    return r_buffer_.length_;
+  }
+
+  //
+  // Same as in the base class.
+  //
+  // virtual int readable() const;
+  //
+  // virtual int writable() const;
+  //
+  // virtual int queued() const;
+  //
+
+  virtual int flushable() const
+  {
+    return flush_;
+  }
+
+  //
+  // Same as in the base class, but
+  // should not be called.
+  //
+  // int drained() const;
+  //
+  // Same as in the base class.
+  //
+  // virtual int wait(int timeout) const;
+  //
+  // Same as in the base class.
+  //
+  // void setSize(unsigned int initialSize,
+  //                  unsigned int thresholdSize,
+  //                      unsigned int maximumSize);
+  //
+
+  virtual unsigned int getPending(unsigned char *&data);
+
+  virtual void pendingReset()
+  {
+    owner_ = 1;
+  }
+
+  virtual void partialReset()
+  {
+    if (owner_ == 1)
+    {
+      Transport::partialReset(r_buffer_);
+    }
+
+    Transport::partialReset(w_buffer_);
+  }
+
+  virtual void fullReset();
+
+  //
+  // Same as in the base class.
+  //
+  // int blocked() const;
+  //
+
+  protected:
+
+  int flush_;
+  int owner_;
+
+  T_buffer r_buffer_;
+
+  z_stream r_stream_;
+  z_stream w_stream_;
+
+  private:
+
+  #ifdef REFERENCES
+
+  static int references_;
+
+  #endif
+};
+
+//
+// Handle memory-to-memory data transfers between
+// an agent and the proxy.
+//
+
+class AgentTransport : public Transport
+{
+  public:
+
+  AgentTransport(int fd);
+
+  virtual ~AgentTransport();
+
+  virtual int read(unsigned char *data, unsigned int size);
+
+  virtual int write(T_write type, const unsigned char *data, const unsigned int size);
+
+  //
+  // These two should never be called.
+  //
+
+  virtual int flush();
+
+  virtual int drain(int limit, int timeout);
+
+  //
+  // Same as in the base class.
+  //
+  // virtual void finish();
+  //
+
+  //
+  // Same as in the base class.
+  //
+  // virtual int length() const
+  //
+
+  virtual int pending() const
+  {
+    return r_buffer_.length_;
+  }
+
+  //
+  // These are intended to operate only
+  // on the internal buffers.
+  //
+
+  virtual int readable() const
+  {
+    return r_buffer_.length_;
+  }
+
+  virtual int writable() const
+  {
+    return control -> TransportMaximumBufferSize;
+  }
+
+  virtual int queued() const
+  {
+    return 0;
+  }
+
+  //
+  // Same as in the base class.
+  //
+  // virtual int flushable() const;
+  //
+  // Same as in the base class, but
+  // should not be called.
+  //
+  // int drained() const;
+  //
+
+  //
+  // Return immediately or will
+  // block until the timeout.
+  //
+
+  virtual int wait(int timeout) const
+  {
+    return 0;
+  }
+
+  //
+  // Same as in the base class.
+  //
+  // void setSize(unsigned int initialSize,
+  //                  unsigned int thresholdSize,
+  //                      unsigned int maximumSize);
+  //
+
+  virtual unsigned int getPending(unsigned char *&data);
+
+  virtual void pendingReset()
+  {
+    owner_ = 1;
+  }
+
+  virtual void partialReset()
+  {
+    if (owner_ == 1)
+    {
+      Transport::partialReset(r_buffer_);
+    }
+
+    Transport::partialReset(w_buffer_);
+  }
+
+  virtual void fullReset();
+
+  //
+  // Same as in the base class.
+  //
+  // int blocked() const;
+  //
+
+  //
+  // The following are specific of the
+  // memory-to-memory transport.
+  //
+
+  int enqueue(const char *data, const int size);
+
+  int dequeue(char *data, int size);
+
+  int queuable()
+  {
+    //
+    // Always allow the agent to enqueue
+    // more data.
+    //
+
+    return control -> TransportMaximumBufferSize;
+  }
+
+  int dequeuable();
+
+  protected:
+
+  //
+  // Lock the buffer to handle reads and
+  // writes safely.
+  //
+
+  #ifdef THREADS
+
+  int lockRead();
+  int lockWrite();
+
+  int unlockRead();
+  int unlockWrite();
+
+  #endif
+
+  //
+  // Data members.
+  //
+
+  int owner_;
+
+  T_buffer r_buffer_;
+
+  //
+  // Mutexes for safe read and write.
+  //
+
+  #ifdef THREADS
+
+  pthread_mutex_t m_read_;
+  pthread_mutex_t m_write_;
+
+  #endif
+
+  private:
+
+  #ifdef REFERENCES
+
+  static int references_;
+
+  #endif
+};
+
+#endif /* Transport_H */