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

     2 /*

     3  * Copyright (c) 2005,2006 INRIA

     4  * All rights reserved.

     5  *

     6  * This program is free software; you can redistribute it and/or modify

     7  * it under the terms of the GNU General Public License version 2 as

     8  * published by the Free Software Foundation;

     9  *

    10  * This program is distributed in the hope that it will be useful,

    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    13  * GNU General Public License for more details.

    14  *

    15  * You should have received a copy of the GNU General Public License

    16  * along with this program; if not, write to the Free Software

    17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    18  *

    19  * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

    20  */

    21 #ifndef NET_DEVICE_H

    22 #define NET_DEVICE_H

    23 

    24 #include <string>

    25 #include <stdint.h>

    26 #include "ns3/callback.h"

    27 #include "ns3/packet.h"

    28 #include "mac-address.h"

    29 

    30 namespace ns3 {

    31 

    32 class Ipv4L4Demux;

    33 class Node;

    34 

    35 /**

    36  * \brief Network layer to device interface

    37  *

    38  * This interface defines the API which the IP and ARP

    39  * layers need to access to manage an instance of a network device 

    40  * layer. It currently does not support MAC-level 

    41  * multicast but this should not be too hard to add by adding

    42  * extra methods to register MAC multicast addresses to

    43  * filter out unwanted packets before handing them to the

    44  * higher layers.

    45  *

    46  * In Linux, this interface is analogous to the interface

    47  * just above dev_queue_xmit() (i.e., IP packet is fully

    48  * constructed with destination MAC address already selected).

    49  * 

    50  * If you want to write a new MAC layer, you need to subclass

    51  * this base class and implement your own version of the 

    52  * NetDevice::SendTo method.

    53  */

    54 class NetDevice {

    55  public:

    56   /**

    57    * \param node base class node pointer of device's node 

    58    */

    59   NetDevice(Node& node, const MacAddress& addr);

    60   virtual ~NetDevice() {}

    61   /**

    62    * \return the current MacAddress of this interface.

    63    */

    64   MacAddress GetAddress (void) const;

    65   /**

    66    * \param mtu MTU value, in bytes, to set for the device

    67    * \return whether the MTU value was within legal bounds

    68    * 

    69    * Override for default MTU defined on a per-type basis.

    70    */

    71   bool SetMtu (const uint16_t mtu);

    72   /**

    73    * \return the link-level MTU in bytes for this interface.

    74    * 

    75    * This value is typically used by the IP layer to perform

    76    * IP fragmentation when needed.

    77    */

    78   uint16_t GetMtu (void) const;

    79   /**

    80    * \param name name of the device (e.g. "eth0")

    81    */

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

    83   /**

    84    * \return name name of the device (e.g. "eth0")

    85    */

    86   std::string GetName(void) const;

    87   /**

    88    * \return true if link is up; false otherwise

    89    */

    90   bool IsLinkUp (void) const;

    91   /**

    92    * \param callback the callback to invoke

    93    *

    94    * Register a callback invoked whenever the link 

    95    * status changes to UP. This callback is typically used

    96    * by the IP/ARP layer to flush the ARP cache 

    97    * whenever the link goes up.

    98    */

    99   void SetLinkChangeCallback (Callback<void> callback);

   100   /**

   101    * \return true if this interface supports a broadcast address,

   102    *         false otherwise.

   103    */

   104   bool IsBroadcast (void) const;

   105   /**

   106    * \return the broadcast address supported by

   107    *         this netdevice.

   108    *

   109    * Calling this method is invalid if IsBroadcast returns

   110    * not true.

   111    */

   112   MacAddress const &GetBroadcast (void) const;

   113   /**

   114    * \return value of m_isMulticast flag

   115    */

   116   bool IsMulticast (void) const;

   117   /**

   118    * \return value of m_isPointToPoint flag

   119    */

   120   bool IsPointToPoint (void) const;

   121   /**

   122    * \param p packet sent from above down to Network Device

   123    * \param dest mac address of the destination (already resolved)

   124    * \param protocolNumber identifies the type of payload contained in

   125    *        this packet. Used to call the right L3Protocol when the packet

   126    *        is received.

   127    * 

   128    *  Called from higher layer to send packet into Network Device

   129    *  to the specified destination MacAddress

   130    * 

   131    * \return whether the Send operation succeeded 

   132    */

   133   bool Send(Packet& p, const MacAddress& dest, uint16_t protocolNumber);

   134 

   135  protected:

   136   /**

   137    * Enable broadcast support. This method should be

   138    * called by subclasses from their constructor

   139    */

   140   void EnableBroadcast (MacAddress broadcast);

   141   /**

   142    * Set m_isBroadcast flag to false

   143    */

   144   void DisableBroadcast (void);

   145   /**

   146    * Set m_isMulticast flag to true

   147    */

   148   void EnableMulticast (void);

   149   /**

   150    * Set m_isMulticast flag to false

   151    */

   152   void DisableMulticast (void);

   153   /**

   154    * Set m_isPointToPoint flag to true

   155    */

   156   void EnablePointToPoint (void);

   157   /**

   158    * Set m_isPointToPoint flag to false

   159    */

   160   void DisablePointToPoint (void);

   161   /**

   162    * When a subclass notices that the link status has changed to up,

   163    * it notifies its parent class by calling this method. This method

   164    * is responsible for notifying any LinkUp callbacks. 

   165    */

   166   void NotifyLinkUp (void);

   167   /**

   168    * When a subclass notices that the link status has changed to 

   169    * down, it notifies its parent class by calling this method.

   170    */

   171   void NotifyLinkDown (void);

   172   /**

   173    * \returns the node base class which contains this network

   174    *          interface.

   175    *

   176    * When a subclass needs to get access to the underlying node

   177    * base class to print the nodeid for example, it can invoke

   178    * this method.

   179    */

   180   Node& GetNode (void) const;

   181 

   182   /**

   183    * \param p packet sent from below up to Network Device

   184    * \param from source mac address of the sender 

   185    * \returns true if the packet was forwarded successfully,

   186    *          false otherwise.

   187    *

   188    * When a subclass gets a packet from the PHY layer, it 

   189    * forwards it to the higher layers by calling this method

   190    * which is responsible for passing it up to the Rx callback.

   191    */

   192   bool ForwardUp (Packet& p);

   193 

   194  private:

   195   /**

   196    * \param p packet to send

   197    * \param dest address of destination to which packet must be sent

   198    * \returns true if the packet could be sent successfully, false

   199    *          otherwise.

   200    *

   201    * This is the private virtual target function of the public Send()

   202    * method.  When the link is Up, this method is invoked to ask 

   203    * subclasses to forward packets down to the PHY layer. Subclasses 

   204    * MUST override this method.

   205    */

   206   virtual bool SendTo (Packet& p, const MacAddress& dest) = 0;

   207   Node&         m_node;

   208   std::string   m_name;

   209   uint16_t      m_ifIndex;

   210   MacAddress    m_address;

   211   MacAddress    m_broadcast;

   212   uint16_t      m_mtu;

   213   bool          m_isUp;

   214   bool          m_isBroadcast;

   215   bool          m_isMulticast;

   216   bool          m_isPointToPoint;

   217   Callback<void> m_linkChangeCallback;

   218 };

   219 

   220 }; // namespace ns3

   221 #endif