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

     2 /*

     3  * Copyright (c) 2013 Universita' di Firenze

     4  *

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

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

     7  * published by the Free Software Foundation;

     8  *

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

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

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

    12  * GNU General Public License for more details.

    13  *

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

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

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

    17  *

    18  * Author: Tommaso Pecorella <tommaso.pecorella@unifi.it>

    19  */

    20 

    21 #ifndef IPV6_PMTU_CACHE_H

    22 #define IPV6_PMTU_CACHE_H

    23 

    24 #include <map>

    25 

    26 #include "ns3/core-module.h"

    27 #include "ns3/ipv6-address.h"

    28 

    29 namespace ns3 {

    30 

    31 /**

    32  * \ingroup ipv6

    33  * \brief This class implements the Path MTU cache, as defined by RFC 1981.

    34  *

    35  * The Path MTU is stored according to the destination address, and it is

    36  * cleared upon expiration (default validity time is 10 minutes).

    37  *

    38  * The "infinite lifetime" PMTU entry type is not implemented, since it is

    39  * useful only in an very limited number of cases. See the RFC for further

    40  * details.

    41  */

    42 

    43 class Ipv6PmtuCache : public Object

    44 {

    45 public:

    46   class Entry;

    47 

    48   /**

    49    * \brief Get the type ID

    50    * \return type ID

    51    */

    52   static TypeId GetTypeId ();

    53 

    54   /**

    55    * \brief Constructor.

    56    */

    57   Ipv6PmtuCache ();

    58 

    59   /**

    60    * \brief Destructor.

    61    */

    62   ~Ipv6PmtuCache ();

    63 

    64   /**

    65    * \brief Dispose object.

    66    */

    67   virtual void DoDispose ();

    68 

    69   /**

    70    * \brief Gets the known Path MTU for the specific destination

    71    * \param dst the destination

    72    * \return the Path MTU (zero if unknown)

    73    */

    74   uint32_t GetPmtu (Ipv6Address dst);

    75 

    76   /**

    77    * \brief Sets the Path MTU for the specific destination

    78    * \param dst the destination

    79    * \param pmtu the Path MTU

    80    */

    81   void SetPmtu (Ipv6Address dst, uint32_t pmtu);

    82 

    83   /**

    84    * \brief Gets the Path MTU validity time

    85    * \return the Path MTU validity time

    86    */

    87   Time GetPmtuValidityTime () const;

    88 

    89   /**

    90    * \brief Sets the Path MTU validity time (minimum is 5 minutes)

    91    * \param validity the Path MTU validity time

    92    * \return true if the change was successful

    93    */

    94   bool SetPmtuValidityTime (Time validity);

    95 

    96 private:

    97   /**

    98    * \brief Clears the Path MTU for the specific destination

    99    * \param dst the destination

   100    */

   101   void ClearPmtu (Ipv6Address dst);

   102 

   103   /**

   104    * \brief Path MTU table

   105    */

   106   std::map<Ipv6Address, uint32_t> m_pathMtu;

   107 

   108   typedef std::map<Ipv6Address, EventId> ::iterator pathMtuTimerIter;

   109   /**

   110    * \brief Path MTU Expiration table

   111    */

   112   std::map<Ipv6Address, EventId> m_pathMtuTimer;

   113 

   114   /**

   115    * \brief Path MTU entry validity time

   116    */

   117   Time m_validityTime;

   118 };

   119 

   120 }

   121 

   122 #endif /* IPV6_PMTU_CACHE_H */