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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2011 University of California, Los Angeles
*
* 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
*
* Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
*/
#ifndef NDN_FORWARDING_STRATEGY_H
#define NDN_FORWARDING_STRATEGY_H
#include "ns3/packet.h"
#include "ns3/callback.h"
#include "ns3/object.h"
#include "ns3/traced-callback.h"
namespace ns3 {
namespace ndn {
class Face;
class Interest;
class ContentObject;
typedef Interest InterestHeader;
typedef ContentObject ContentObjectHeader;
class Pit;
namespace pit { class Entry; }
class FibFaceMetric;
class Fib;
namespace fib { class Entry; }
class ContentStore;
/**
* \ingroup ndn
* \brief Abstract base class for Ndn forwarding strategies
*/
class ForwardingStrategy :
public Object
{
public:
static TypeId GetTypeId (void);
/**
* @brief Helper function to retrieve logging name for the forwarding strategy
*/
static std::string GetLogName ();
/**
* @brief Default constructor
*/
ForwardingStrategy ();
virtual ~ForwardingStrategy ();
/**
* \brief Actual processing of incoming Ndn interests. Note, interests do not have payload
*
* Processing Interest packets
* @param face incoming face
* @param header deserialized Interest header
* @param origPacket original packet
*/
virtual void
OnInterest (Ptr<Face> face,
Ptr<const Interest> header,
Ptr<const Packet> origPacket);
/**
* \brief Actual processing of incoming Ndn content objects
*
* Processing ContentObject packets
* @param face incoming face
* @param header deserialized ContentObject header
* @param payload data packet payload
* @param origPacket original packet
*/
virtual void
OnData (Ptr<Face> face,
Ptr<const ContentObject> header,
Ptr<Packet> payload,
Ptr<const Packet> origPacket);
/**
* @brief Event fired just before PIT entry is removed by timeout
* @param pitEntry PIT entry to be removed
*/
virtual void
WillEraseTimedOutPendingInterest (Ptr<pit::Entry> pitEntry);
/**
* @brief Event fired every time face is added to NDN stack
* @param face face to be removed
*/
virtual void
AddFace (Ptr<Face> face);
/**
* @brief Event fired every time face is removed from NDN stack
* @param face face to be removed
*
* For example, when an application terminates, AppFace is removed and this method called by NDN stack.
*/
virtual void
RemoveFace (Ptr<Face> face);
/**
* @brief Event fired every time a FIB entry is added to FIB
* @param fibEntry FIB entry that was added
*/
virtual void
DidAddFibEntry (Ptr<fib::Entry> fibEntry);
/**
* @brief Fired just before FIB entry will be removed from FIB
* @param fibEntry FIB entry that will be removed
*/
virtual void
WillRemoveFibEntry (Ptr<fib::Entry> fibEntry);
protected:
/**
* @brief An event that is fired every time a new PIT entry is created
*
* Note that if NDN node is receiving a similar interest (interest for the same name),
* then either DidReceiveDuplicateInterest, DidSuppressSimilarInterest, or DidForwardSimilarInterest
* will be called
*
* Suppression of similar Interests is controlled using ShouldSuppressIncomingInterest virtual method
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
* @param pitEntry created PIT entry (incoming and outgoing face sets are empty)
*
* @see DidReceiveDuplicateInterest, DidSuppressSimilarInterest, DidForwardSimilarInterest, ShouldSuppressIncomingInterest
*/
virtual void
DidCreatePitEntry (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief An event that is fired every time a new PIT entry cannot be created (e.g., PIT container imposes a limit)
*
* Note that this call can be called only for non-similar Interest (i.e., there is an attempt to create a new PIT entry).
* For any non-similar Interests, either FailedToCreatePitEntry or DidCreatePitEntry is called.
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
*/
virtual void
FailedToCreatePitEntry (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket);
/**
* @brief An event that is fired every time a duplicated Interest is received
*
* This even is the last action that is performed before the Interest processing is halted
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*
* @see DidReceiveDuplicateInterest, DidSuppressSimilarInterest, DidForwardSimilarInterest, ShouldSuppressIncomingInterest
*/
virtual void
DidReceiveDuplicateInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief An event that is fired every time when a similar Interest is received and suppressed (collapsed)
*
* This even is the last action that is performed before the Interest processing is halted
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*
* @see DidReceiveDuplicateInterest, DidForwardSimilarInterest, ShouldSuppressIncomingInterest
*/
virtual void
DidSuppressSimilarInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief An event that is fired every time when a similar Interest is received and further forwarded (not suppressed/collapsed)
*
* This even is fired just before handling the Interest to PropagateInterest method
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*
* @see DidReceiveDuplicateInterest, DidSuppressSimilarInterest, ShouldSuppressIncomingInterest
*/
virtual void
DidForwardSimilarInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief An even that is fired when Interest cannot be forwarded
*
* Note that the event will not fire if retransmission detection is enabled (by default)
* and retransmitted Interest cannot by forwarded. For more details, refer to the implementation.
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*
* @see DetectRetransmittedInterest
*/
virtual void
DidExhaustForwardingOptions (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Method that implements logic to distinguish between new and retransmitted interest
*
* This method is called only when DetectRetransmissions attribute is set true (by default).
*
* Currently, the retransmission detection logic relies on the fact that list of incoming faces
* already has inFace (i.e., a similar interest is received on the same face more than once).
*
* @param inFace incoming face
* @param header deserialized Interest header
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
* @return true if Interest should be considered as retransmitted
*/
virtual bool
DetectRetransmittedInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Even fired just before Interest will be satisfied
*
* Note that when Interest is satisfied from the cache, incoming face will be 0
*
* @param inFace incoming face
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*/
virtual void
WillSatisfyPendingInterest (Ptr<Face> inFace,
Ptr<pit::Entry> pitEntry);
/**
* @brief Actual procedure to satisfy Interest
*
* Note that when Interest is satisfied from the cache, incoming face will be 0
*
* @param inFace incoming face
* @param header deserialized ContentObject header
* @param payload ContentObject payload
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*/
virtual void
SatisfyPendingInterest (Ptr<Face> inFace, // 0 allowed (from cache)
Ptr<const ContentObject> header,
Ptr<const Packet> payload,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Event which is fired just after data was send out on the face
*
* @param inFace incoming face of the ContentObject
* @param outFace outgoing face
* @param header deserialized ContentObject header
* @param payload ContentObject payload
* @param origPacket original packet
* @param pitEntry an existing PIT entry, corresponding to the duplicated Interest
*/
virtual void
DidSendOutData (Ptr<Face> inFace,
Ptr<Face> outFace,
Ptr<const ContentObject> header,
Ptr<const Packet> payload,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Event which is fired every time a requested (solicited) DATA packet (there is an active PIT entry) is received
*
* @param inFace incoming face
* @param header deserialized ContentObject header
* @param payload ContentObject payload
* @param origPacket original packet
* @param didCreateCacheEntry flag indicating whether a cache entry was added for this data packet or not (e.g., packet already exists in cache)
*/
virtual void
DidReceiveSolicitedData (Ptr<Face> inFace,
Ptr<const ContentObject> header,
Ptr<const Packet> payload,
Ptr<const Packet> origPacket,
bool didCreateCacheEntry);
/**
* @brief Event which is fired every time an unsolicited DATA packet (no active PIT entry) is received
*
* The current implementation allows ignoring unsolicited DATA (by default), or cache it by setting
* attribute CacheUnsolicitedData true
*
* @param inFace incoming face
* @param header deserialized ContentObject header
* @param payload ContentObject payload
* @param origPacket original packet
* @param didCreateCacheEntry flag indicating whether a cache entry was added for this data packet or not (e.g., packet already exists in cache)
*/
virtual void
DidReceiveUnsolicitedData (Ptr<Face> inFace,
Ptr<const ContentObject> header,
Ptr<const Packet> payload,
Ptr<const Packet> origPacket,
bool didCreateCacheEntry);
/**
* @brief Method implementing logic to suppress (collapse) similar Interests
*
* In the base class implementation this method checks list of incoming/outgoing faces of the PIT entry
* (for new Intersets, both lists are empty before this call)
*
* For more details, refer to the source code.
*
* @param inFace incoming face
* @param header deserialized ContentObject header
* @param payload ContentObject payload
* @param origPacket original packet
*/
virtual bool
ShouldSuppressIncomingInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Method to check whether Interest can be send out on the particular face or not
*
* In the base class, this method perfoms two checks:
* 1. If inFace is equal to outFace (when equal, Interest forwarding is prohibited)
* 2. Whether Interest should be suppressed (list of outgoing faces include outFace),
* considering (if enabled) retransmission logic
*
* @param inFace incoming face of the Interest
* @param outFace proposed outgoing face of the Interest
* @param header parsed Interest header
* @param origPacket original Interest packet
* @param pitEntry reference to PIT entry (reference to corresponding FIB entry inside)
*
* @see DetectRetransmittedInterest
*/
virtual bool
CanSendOutInterest (Ptr<Face> inFace,
Ptr<Face> outFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Method implementing actual interest forwarding, taking into account CanSendOutInterest decision
*
* If event returns false, then there is some kind of a problem exists
*
* @param inFace incoming face of the Interest
* @param outFace proposed outgoing face of the Interest
* @param header parsed Interest header
* @param origPacket original Interest packet
* @param pitEntry reference to PIT entry (reference to corresponding FIB entry inside)
*
* @see CanSendOutInterest
*/
virtual bool
TrySendOutInterest (Ptr<Face> inFace,
Ptr<Face> outFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Event fired just after forwarding the Interest
*
* @param inFace incoming face of the Interest
* @param outFace outgoing face of the Interest
* @param header parsed Interest header
* @param origPacket original Interest packet
* @param pitEntry reference to PIT entry (reference to corresponding FIB entry inside)
*/
virtual void
DidSendOutInterest (Ptr<Face> inFace,
Ptr<Face> outFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Wrapper method, which performs general tasks and calls DoPropagateInterest method
*
* General tasks so far are adding face to the list of incoming face, updating
* PIT entry lifetime, calling DoPropagateInterest, and retransmissions (enabled by default).
*
* @param inFace incoming face
* @param header Interest header
* @param origPacket original Interest packet
* @param pitEntry reference to PIT entry (reference to corresponding FIB entry inside)
*
* @see DoPropagateInterest
*/
virtual void
PropagateInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry);
/**
* @brief Virtual method to perform Interest propagation according to the forwarding strategy logic
*
* In most cases, this is the call that needs to be implemented/re-implemented in order
* to perform forwarding of Interests according to the desired logic.
*
* There is also PropagateInterest method (generally, do not require to be overriden)
* which performs general tasks (adding face to the list of incoming face, updating
* PIT entry lifetime, calling DoPropagateInterest, as well as perform retransmissions (enabled by default).
*
* @param inFace incoming face
* @param header Interest header
* @param origPacket original Interest packet
* @param pitEntry reference to PIT entry (reference to corresponding FIB entry inside)
*
* @return true if interest was successfully propagated, false if all options have failed
*
* @see PropagateInterest
*/
virtual bool
DoPropagateInterest (Ptr<Face> inFace,
Ptr<const Interest> header,
Ptr<const Packet> origPacket,
Ptr<pit::Entry> pitEntry) = 0;
protected:
// inherited from Object class
virtual void NotifyNewAggregate (); ///< @brief Even when object is aggregated to another Object
virtual void DoDispose (); ///< @brief Do cleanup
protected:
Ptr<Pit> m_pit; ///< \brief Reference to PIT to which this forwarding strategy is associated
Ptr<Fib> m_fib; ///< \brief FIB
Ptr<ContentStore> m_contentStore; ///< \brief Content store (for caching purposes only)
bool m_cacheUnsolicitedData;
bool m_detectRetransmissions;
TracedCallback<Ptr<const Interest>,
Ptr<const Face> > m_outInterests; ///< @brief Transmitted interests trace
TracedCallback<Ptr<const Interest>,
Ptr<const Face> > m_inInterests; ///< @brief trace of incoming Interests
TracedCallback<Ptr<const Interest>,
Ptr<const Face> > m_dropInterests; ///< @brief trace of dropped Interests
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
TracedCallback<Ptr<const ContentObject>, Ptr<const Packet>,
bool /*from cache*/,
Ptr<const Face> > m_outData; ///< @brief trace of outgoing Data
TracedCallback<Ptr<const ContentObject>, Ptr<const Packet>,
Ptr<const Face> > m_inData; ///< @brief trace of incoming Data
TracedCallback<Ptr<const ContentObject>, Ptr<const Packet>,
Ptr<const Face> > m_dropData; ///< @brief trace of dropped Data
};
} // namespace ndn
} // namespace ns3
#endif /* NDN_FORWARDING_STRATEGY_H */