/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

 /*

  * Copyright (c) 2008 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 EMU_NET_DEVICE_H

 #define EMU_NET_DEVICE_H

 #include <string.h>

 #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/system-thread.h"

 namespace ns3 {

 class Queue;

 /**

  * \class EmuNetDevice

  * \brief A Device for an Emu Network Link.

  */

 class EmuNetDevice : public NetDevice 

 {

 public:

   static TypeId GetTypeId (void);

   /**

    * Construct a EmuNetDevice

    *

    * This is the constructor for the EmuNetDevice.  It takes as a

    */

   EmuNetDevice ();

   /**

    * Destroy a EmuNetDevice

    *

    * This is the destructor for the EmuNetDevice.

    */

   virtual ~EmuNetDevice ();

   /**

    * Set the Data Rate used for transmission of packets.  

    *

    * @see Attach ()

    * @param bps the data rate at which this object operates

    */

   void SetDataRate (DataRate bps);

   /**

    * Set the inteframe gap used to separate packets.  The interframe gap

    * defines the minimum space required between packets sent by this device.

    *

    * @param t the interframe gap time

    */

   void SetInterframeGap (Time t);

   /**

    * Set a start time for the device.

    *

    * @param tStart the start time

    */

   void Start (Time tStart);

   /**

    * Set a stop time for the device.

    *

    * @param tStop the stop time

    */

   void Stop (Time tStop);

   /**

    * Attach a queue to the EmuNetDevice.

    *

    * The EmuNetDevice "owns" a queue that implements a queueing 

    * method such as DropTail or RED.  

    *

    * @see Queue

    * @see DropTailQueue

    * @param queue Ptr to the new queue.

    */

   void SetQueue (Ptr<Queue> queue);

   /**

    * Receive a packet.

    *

    * The EmuNetDevice receives packets from its socket reader

    * and forwards them up the protocol stack.  This is the public method

    * used by the reader to indicate that a packet has arrived at the device.

    *

    * @param p Ptr to the received packet.

    */

   void Receive (Ptr<Packet> p);

   /**

    * Assign a MAC address to this device.

    *

    * @see Mac48Address

    * @param addr The new address.

    */

   void SetAddress (Mac48Address addr);

 //

 // Pure virtual methods inherited from NetDevice we must implement.

 //

   virtual void SetName(const std::string name);

   virtual std::string GetName(void) const;

   virtual void SetIfIndex(const uint32_t index);

   virtual uint32_t GetIfIndex(void) const;

   virtual Ptr<Channel> GetChannel (void) const;

   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 SetLinkChangeCallback (Callback<void> callback);

   virtual bool IsBroadcast (void) const;

   virtual Address GetBroadcast (void) const;

   virtual bool IsMulticast (void) const;

   /**

    * \brief Make and return a MAC multicast address using the provided

    *        multicast group

    *

    * RFC 1112 says that an Ipv4 host group address is mapped to an Ethernet 

    * multicast address by placing the low-order 23-bits of the IP address into 

    * the low-order 23 bits of the Ethernet multicast address 

    * 01-00-5E-00-00-00 (hex).

    *

    * This method performs the multicast address creation function appropriate

    * to an EUI-48-based CSMA device.  This MAC address is encapsulated in an

    *  abstract Address to avoid dependencies on the exact address format.

    *

    * \param multicastGroup The IP address for the multicast group destination

    * of the packet.

    * \return The MAC multicast Address used to send packets to the provided

    * multicast group.

    *

    * \see Ipv4Address

    * \see Mac48Address

    * \see Address

    */

   virtual Address GetMulticast (Ipv4Address multicastGroup) const;

   /**

    * Is this a point to point link?

    * \returns false.

    */

   virtual bool IsPointToPoint (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 (PromiscReceiveCallback cb);

   virtual bool SupportsSendFrom (void) const;

 private:

   virtual void DoDispose (void);

   /**

    * Call out to a separate process running as suid root in order to get a raw 

    * socket.  We do this to avoid having the entire simulation running as root.

    * If this method returns, we'll have a raw socket waiting for us in m_sock.

    */

   void CreateSocket (void);

   /**

    * Figure out where the raw socket creation process lives on the system.

    */

   std::string FindCreator (void);

   /**

    * Get a copy of the attached Queue.

    *

    * This method is provided for any derived class that may need to get

    * direct access to the underlying queue.

    *

    * @returns Ptr to the queue.

    */

   Ptr<Queue> GetQueue(void) const; 

   /**

    * Spin up the device

    */

   void StartDevice (void);

   /**

    * Tear down the device

    */

   void StopDevice (void);

   /**

    * Loop to read and process packets

    */

   void ReadThread (void);

   /**

    * Method to handle received packets.  Synchronized with simulator via ScheduleNow from ReadThread.

    */

   void ForwardUp (uint8_t *buf, uint32_t len);

   /**

    * Adds the necessary headers and trailers to a packet of data in order to

    * respect the protocol implemented by the agent.

    */

   void AddHeader(Ptr<Packet> p, uint16_t protocolNumber);

   /**

    * Removes, from a packet of data, all headers and trailers that

    * relate to the protocol implemented by the agent

    * \return Returns true if the packet should be forwarded up the

    * protocol stack.

    */

   bool ProcessHeader(Ptr<Packet> p, uint16_t& param);

   /**

    * Start Sending a Packet Down the Wire.

    *

    * @returns true if success, false on failure

    */

   bool TransmitStart (Ptr<Packet> p);

   void NotifyLinkUp (void);

   /**

    * The Queue which this EmuNetDevice uses as a packet source.

    * Management of this Queue has been delegated to the EmuNetDevice

    * and it has the responsibility for deletion.

    * @see class Queue

    * @see class DropTailQueue

    */

   Ptr<Queue> m_queue;

   /**

    * The trace source for the packet reception events that the device can

    * fire.

    *

    * @see class CallBackTraceSource

    */

   TracedCallback<Ptr<const Packet> > m_rxTrace;

   /**

    * The trace source for the packet drop events that the device can

    * fire.

    *

    * @see class CallBackTraceSource

    */

   TracedCallback<Ptr<const Packet> > m_dropTrace;

   /**

    * Time to start spinning up the device

    */

   Time m_tStart;

   /**

    * Time to start tearing down the device

    */

   Time m_tStop;

   EventId m_startEvent;

   EventId m_stopEvent;

   int32_t m_sock;

   Ptr<SystemThread> m_readThread;

   /**

    * The Node to which this device is attached.

    */

   Ptr<Node> m_node;

   /**

    * The MAC address which has been assigned to this device.

    */

   Mac48Address m_address;

   /**

    * The callback used to notify higher layers that a packet has been received.

    */

   NetDevice::ReceiveCallback m_rxCallback;

   /**

    * The callback used to notify higher layers that a packet has been received in promiscuous mode.

    */

   NetDevice::PromiscReceiveCallback m_promiscRxCallback;

   /**

    * The ns-3 interface index (in the sense of net device index) that has been assigned to this network device.

    */

   uint32_t m_ifIndex;

   /**

    * The Unix interface index that we got from the system and which corresponds to the interface (e.g., "eth1")

    * we are using to talk to the network.  Valid when m_sock is valid.

    */

   int32_t m_sll_ifindex;

   /**

    * The human readable name of this device.

    */

   std::string m_name;

   /**

    * Flag indicating whether or not the link is up.  In this case,

    * whether or not the device is connected to a channel.

    */

   bool m_linkUp;

   /**

    * Callback to fire if the link changes state (up or down).

    */

   Callback<void> m_linkChangeCallback;

   /**

    * The unix/linux name of the underlying device (e.g., eth0)

    */

   std::string m_deviceName;

 };

 } // namespace ns3

 #endif // EMU_NET_DEVICE_H