tap-bridge.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2009 University of Washington
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef TAP_BRIDGE_H
#define TAP_BRIDGE_H

#include <cstring>
#include "ns3/address.h"
#include "ns3/net-device.h"
#include "ns3/node.h"
#include "ns3/callback.h"
#include "ns3/packet.h"
#include "ns3/traced-callback.h"
#include "ns3/event-id.h"
#include "ns3/nstime.h"
#include "ns3/data-rate.h"
#include "ns3/ptr.h"
#include "ns3/mac48-address.h"
#include "ns3/unix-fd-reader.h"

namespace ns3 {

class TapBridgeFdReader : public FdReader
{
private:
  FdReader::Data DoRead (void);
};

class Node;

class TapBridge : public NetDevice
{
public:
  static TypeId GetTypeId (void);

  enum Mode {
    ILLEGAL,         
    CONFIGURE_LOCAL, 
    USE_LOCAL,       
    USE_BRIDGE, 
  };

  TapBridge ();
  virtual ~TapBridge ();

  Ptr<NetDevice> GetBridgedNetDevice (void);

  void SetBridgedNetDevice (Ptr<NetDevice> bridgedDevice);

  void Start (Time tStart);

  void Stop (Time tStop);

  void SetMode (TapBridge::Mode mode);

  TapBridge::Mode  GetMode (void);

  //
  // The following methods are inherited from NetDevice base class and are
  // documented there.
  //
  virtual void SetIfIndex (const uint32_t index);
  virtual uint32_t GetIfIndex (void) const;
  virtual Ptr<Channel> GetChannel (void) const;
  virtual void SetAddress (Address address);
  virtual Address GetAddress (void) const;
  virtual bool SetMtu (const uint16_t mtu);
  virtual uint16_t GetMtu (void) const;
  virtual bool IsLinkUp (void) const;
  virtual void AddLinkChangeCallback (Callback<void> callback);
  virtual bool IsBroadcast (void) const;
  virtual Address GetBroadcast (void) const;
  virtual bool IsMulticast (void) const;
  virtual Address GetMulticast (Ipv4Address multicastGroup) const;
  virtual bool IsPointToPoint (void) const;
  virtual bool IsBridge (void) const;
  virtual bool Send (Ptr<Packet> packet, const Address& dest, uint16_t protocolNumber);
  virtual bool SendFrom (Ptr<Packet> packet, const Address& source, const Address& dest, uint16_t protocolNumber);
  virtual Ptr<Node> GetNode (void) const;
  virtual void SetNode (Ptr<Node> node);
  virtual bool NeedsArp (void) const;
  virtual void SetReceiveCallback (NetDevice::ReceiveCallback cb);
  virtual void SetPromiscReceiveCallback (NetDevice::PromiscReceiveCallback cb);
  virtual bool SupportsSendFrom () const;
  virtual Address GetMulticast (Ipv6Address addr) const;

protected:
  virtual void DoDispose (void);

  bool ReceiveFromBridgedDevice (Ptr<NetDevice> device, Ptr<const Packet> packet, uint16_t protocol,
                                 Address const &src, Address const &dst, PacketType packetType);

  bool DiscardFromBridgedDevice (Ptr<NetDevice> device, Ptr<const Packet> packet, uint16_t protocol, Address const &src);

private:

  void CreateTap (void);

  void StartTapDevice (void);

  void StopTapDevice (void);

  void ReadCallback (uint8_t *buf, ssize_t len);

  /*
   * Forward a packet received from the tap device to the bridged ns-3 
   * device
   *
   * \param buf A character buffer containing the actual packet bits that were
   *            received from the host.
   * \param buf The length of the buffer.
   */
  void ForwardToBridgedDevice (uint8_t *buf, ssize_t len);

  Ptr<Packet> Filter (Ptr<Packet> packet, Address *src, Address *dst, uint16_t *type);

  void NotifyLinkUp (void);

  NetDevice::ReceiveCallback m_rxCallback;

  NetDevice::PromiscReceiveCallback m_promiscRxCallback;

  Ptr<Node> m_node;


  uint32_t m_ifIndex;

  uint16_t m_mtu;

  int m_sock;

  EventId m_startEvent;

  EventId m_stopEvent;

  Ptr<TapBridgeFdReader> m_fdReader;

  Mode m_mode;

  Mac48Address m_address;

  Time m_tStart;

  Time m_tStop;

  std::string m_tapDeviceName;

  Ipv4Address m_tapGateway;

  Ipv4Address m_tapIp;
  Mac48Address m_tapMac;

  Ipv4Mask m_tapNetmask;

  Ptr<NetDevice> m_bridgedDevice;
  bool m_ns3AddressRewritten;

  uint8_t *m_packetBuffer;

  /*
   * a copy of the node id so the read thread doesn't have to GetNode() in
   * in order to find the node ID.  Thread unsafe reference counting in 
   * multithreaded apps is not a good thing.
   */
  uint32_t m_nodeId;

  bool m_linkUp;

  TracedCallback<> m_linkChangeCallbacks;
};

} // namespace ns3

#endif /* TAP_BRIDGE_H */