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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>
* Ilya Moiseenko <iliamo@cs.ucla.edu>
*/
#include "ndn-forwarding-strategy.h"
#include "ns3/ndn-pit.h"
#include "ns3/ndn-pit-entry.h"
#include "ns3/ndn-interest-header.h"
#include "ns3/ndn-content-object-header.h"
#include "ns3/ndn-pit.h"
#include "ns3/ndn-fib.h"
#include "ns3/ndn-content-store.h"
#include "ns3/ndn-face.h"
#include "ns3/assert.h"
#include "ns3/ptr.h"
#include "ns3/log.h"
#include "ns3/simulator.h"
#include "ns3/boolean.h"
#include "ns3/string.h"
#include <boost/ref.hpp>
#include <boost/foreach.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/bind.hpp>
#include <boost/tuple/tuple.hpp>
namespace ll = boost::lambda;
NS_LOG_COMPONENT_DEFINE ("ndn.ForwardingStrategy");
namespace ns3 {
namespace ndn {
NS_OBJECT_ENSURE_REGISTERED (ForwardingStrategy);
TypeId ForwardingStrategy::GetTypeId (void)
{
static TypeId tid = TypeId ("ns3::ndn::ForwardingStrategy")
.SetGroupName ("Ndn")
.SetParent<Object> ()
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
.AddTraceSource ("OutInterests", "OutInterests", MakeTraceSourceAccessor (&ForwardingStrategy::m_outInterests))
.AddTraceSource ("InInterests", "InInterests", MakeTraceSourceAccessor (&ForwardingStrategy::m_inInterests))
.AddTraceSource ("DropInterests", "DropInterests", MakeTraceSourceAccessor (&ForwardingStrategy::m_dropInterests))
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
.AddTraceSource ("OutData", "OutData", MakeTraceSourceAccessor (&ForwardingStrategy::m_outData))
.AddTraceSource ("InData", "InData", MakeTraceSourceAccessor (&ForwardingStrategy::m_inData))
.AddTraceSource ("DropData", "DropData", MakeTraceSourceAccessor (&ForwardingStrategy::m_dropData))
.AddAttribute ("CacheUnsolicitedData", "Cache overheard data that have not been requested",
BooleanValue (false),
MakeBooleanAccessor (&ForwardingStrategy::m_cacheUnsolicitedData),
MakeBooleanChecker ())
.AddAttribute ("DetectRetransmissions", "If non-duplicate interest is received on the same face more than once, "
"it is considered a retransmission",
BooleanValue (true),
MakeBooleanAccessor (&ForwardingStrategy::m_detectRetransmissions),
MakeBooleanChecker ())
;
return tid;
}
ForwardingStrategy::ForwardingStrategy ()
{
}
ForwardingStrategy::~ForwardingStrategy ()
{
}
void
ForwardingStrategy::NotifyNewAggregate ()
{
if (m_pit == 0)
{
m_pit = GetObject<Pit> ();
}
if (m_fib == 0)
{
m_fib = GetObject<Fib> ();
}
if (m_contentStore == 0)
{
m_contentStore = GetObject<ContentStore> ();
}
Object::NotifyNewAggregate ();
}
void
ForwardingStrategy::DoDispose ()
{
m_pit = 0;
m_contentStore = 0;
m_fib = 0;
Object::DoDispose ();
}
void
ForwardingStrategy::OnInterest (const Ptr<Face> &incomingFace,
Ptr<InterestHeader> &header,
const Ptr<const Packet> &packet)
{
m_inInterests (header, incomingFace);
Ptr<pit::Entry> pitEntry = m_pit->Lookup (*header);
if (pitEntry == 0)
{
pitEntry = m_pit->Create (header);
if (pitEntry != 0)
{
DidCreatePitEntry (incomingFace, header, packet, pitEntry);
}
else
{
FailedToCreatePitEntry (incomingFace, header, packet);
return;
}
}
bool isDuplicated = true;
if (!pitEntry->IsNonceSeen (header->GetNonce ()))
{
pitEntry->AddSeenNonce (header->GetNonce ());
isDuplicated = false;
}
if (isDuplicated)
{
DidReceiveDuplicateInterest (incomingFace, header, packet, pitEntry);
return;
}
Ptr<Packet> contentObject;
Ptr<const ContentObjectHeader> contentObjectHeader; // used for tracing
Ptr<const Packet> payload; // used for tracing
boost::tie (contentObject, contentObjectHeader, payload) = m_contentStore->Lookup (header);
if (contentObject != 0)
{
NS_ASSERT (contentObjectHeader != 0);
pitEntry->AddIncoming (incomingFace/*, Seconds (1.0)*/);
// Do data plane performance measurements
WillSatisfyPendingInterest (0, pitEntry);
// Actually satisfy pending interest
SatisfyPendingInterest (0, contentObjectHeader, payload, contentObject, pitEntry);
return;
}
if (ShouldSuppressIncomingInterest (incomingFace, pitEntry))
{
pitEntry->AddIncoming (incomingFace/*, header->GetInterestLifetime ()*/);
// update PIT entry lifetime
pitEntry->UpdateLifetime (header->GetInterestLifetime ());
// Suppress this interest if we're still expecting data from some other face
NS_LOG_DEBUG ("Suppress interests");
m_dropInterests (header, incomingFace);
return;
}
PropagateInterest (incomingFace, header, packet, pitEntry);
}
void
ForwardingStrategy::OnData (const Ptr<Face> &incomingFace,
Ptr<ContentObjectHeader> &header,
Ptr<Packet> &payload,
const Ptr<const Packet> &packet)
{
NS_LOG_FUNCTION (incomingFace << header->GetName () << payload << packet);
m_inData (header, payload, incomingFace);
// Lookup PIT entry
Ptr<pit::Entry> pitEntry = m_pit->Lookup (*header);
if (pitEntry == 0)
{
DidReceiveUnsolicitedData (incomingFace, header, payload);
return;
}
else
{
// Add or update entry in the content store
m_contentStore->Add (header, payload);
}
while (pitEntry != 0)
{
// Do data plane performance measurements
WillSatisfyPendingInterest (incomingFace, pitEntry);
// Actually satisfy pending interest
SatisfyPendingInterest (incomingFace, header, payload, packet, pitEntry);
// Lookup another PIT entry
pitEntry = m_pit->Lookup (*header);
}
}
void
ForwardingStrategy::DidReceiveDuplicateInterest (const Ptr<Face> &incomingFace,
Ptr<InterestHeader> &header,
const Ptr<const Packet> &packet,
Ptr<pit::Entry> pitEntry)
{
NS_LOG_FUNCTION (this << boost::cref (*incomingFace));
/////////////////////////////////////////////////////////////////////////////////////////
// //
// !!!! IMPORTANT CHANGE !!!! Duplicate interests will create incoming face entry !!!! //
// //
/////////////////////////////////////////////////////////////////////////////////////////
pitEntry->AddIncoming (incomingFace);
m_dropInterests (header, incomingFace);
}
void
ForwardingStrategy::DidExhaustForwardingOptions (const Ptr<Face> &incomingFace,
Ptr<InterestHeader> header,
const Ptr<const Packet> &packet,
Ptr<pit::Entry> pitEntry)
{
NS_LOG_FUNCTION (this << boost::cref (*incomingFace));
m_dropInterests (header, incomingFace);
}
void
ForwardingStrategy::FailedToCreatePitEntry (const Ptr<Face> &incomingFace,
Ptr<InterestHeader> header,
const Ptr<const Packet> &packet)
{
NS_LOG_FUNCTION (this);
m_dropInterests (header, incomingFace);
}
void
ForwardingStrategy::DidCreatePitEntry (const Ptr<Face> &incomingFace,
Ptr<InterestHeader> header,
const Ptr<const Packet> &packet,
Ptr<pit::Entry> pitEntrypitEntry)
{
}
bool
ForwardingStrategy::DetectRetransmittedInterest (const Ptr<Face> &incomingFace,
Ptr<pit::Entry> pitEntry)
{
pit::Entry::in_iterator inFace = pitEntry->GetIncoming ().find (incomingFace);
bool isRetransmitted = false;
if (inFace != pitEntry->GetIncoming ().end ())
{
// this is almost definitely a retransmission. But should we trust the user on that?
isRetransmitted = true;
}
return isRetransmitted;
}
void
ForwardingStrategy::SatisfyPendingInterest (const Ptr<Face> &incomingFace,
Ptr<const ContentObjectHeader> header,
Ptr<const Packet> payload,
const Ptr<const Packet> &packet,
Ptr<pit::Entry> pitEntry)
{
if (incomingFace != 0)
pitEntry->RemoveIncoming (incomingFace);
//satisfy all pending incoming Interests
BOOST_FOREACH (const pit::IncomingFace &incoming, pitEntry->GetIncoming ())
{
bool ok = incoming.m_face->Send (packet->Copy ());
if (ok)
{
m_outData (header, payload, incomingFace == 0, incoming.m_face);
DidSendOutData (incoming.m_face, header, payload, packet);
NS_LOG_DEBUG ("Satisfy " << *incoming.m_face);
}
else
{
m_dropData (header, payload, incoming.m_face);
NS_LOG_DEBUG ("Cannot satisfy data to " << *incoming.m_face);
}
// successfull forwarded data trace
}
// All incoming interests are satisfied. Remove them
pitEntry->ClearIncoming ();
// Remove all outgoing faces
pitEntry->ClearOutgoing ();
// Set pruning timout on PIT entry (instead of deleting the record)
m_pit->MarkErased (pitEntry);
}
void
ForwardingStrategy::DidReceiveUnsolicitedData (const Ptr<Face> &incomingFace,
Ptr<const ContentObjectHeader> header,
Ptr<const Packet> payload)
{
if (m_cacheUnsolicitedData)
{
// Optimistically add or update entry in the content store
m_contentStore->Add (header, payload);
}
else
{
// Drop data packet if PIT entry is not found
// (unsolicited data packets should not "poison" content store)
//drop dulicated or not requested data packet
m_dropData (header, payload, incomingFace);
}
}
void
ForwardingStrategy::WillSatisfyPendingInterest (const Ptr<Face> &incomingFace,
Ptr<pit::Entry> pitEntry)
{
pit::Entry::out_iterator out = pitEntry->GetOutgoing ().find (incomingFace);
// If we have sent interest for this data via this face, then update stats.
if (out != pitEntry->GetOutgoing ().end ())
{
pitEntry->GetFibEntry ()->UpdateFaceRtt (incomingFace, Simulator::Now () - out->m_sendTime);
}
}
bool
ForwardingStrategy::ShouldSuppressIncomingInterest (const Ptr<Face> &incomingFace,
Ptr<pit::Entry> pitEntry)
{
bool isNew = pitEntry->GetIncoming ().size () == 0 && pitEntry->GetOutgoing ().size () == 0;
if (isNew) return false; // never suppress new interests
bool isRetransmitted = m_detectRetransmissions && // a small guard
DetectRetransmittedInterest (incomingFace, pitEntry);
if (pitEntry->GetOutgoing ().find (incomingFace) != pitEntry->GetOutgoing ().end ())
{
NS_LOG_DEBUG ("Non duplicate interests from the face we have sent interest to. Don't suppress");
// got a non-duplicate interest from the face we have sent interest to
// Probably, there is no point in waiting data from that face... Not sure yet
// If we're expecting data from the interface we got the interest from ("producer" asks us for "his own" data)
// Mark interface YELLOW, but keep a small hope that data will come eventually.
// ?? not sure if we need to do that ?? ...
// pitEntry->GetFibEntry ()->UpdateStatus (incomingFace, fib::FaceMetric::NDN_FIB_YELLOW);
}
else
if (!isNew && !isRetransmitted)
{
return true;
}
return false;
}
void
ForwardingStrategy::PropagateInterest (const Ptr<Face> &incomingFace,
Ptr<InterestHeader> header,
const Ptr<const Packet> &packet,
Ptr<pit::Entry> pitEntry)
{
bool isRetransmitted = m_detectRetransmissions && // a small guard
DetectRetransmittedInterest (incomingFace, pitEntry);
pitEntry->AddIncoming (incomingFace/*, header->GetInterestLifetime ()*/);
/// @todo Make lifetime per incoming interface
pitEntry->UpdateLifetime (header->GetInterestLifetime ());
bool propagated = DoPropagateInterest (incomingFace, header, packet, pitEntry);
if (!propagated && isRetransmitted) //give another chance if retransmitted
{
// increase max number of allowed retransmissions
pitEntry->IncreaseAllowedRetxCount ();
// try again
propagated = DoPropagateInterest (incomingFace, header, packet, pitEntry);
}
// ForwardingStrategy will try its best to forward packet to at least one interface.
// If no interests was propagated, then there is not other option for forwarding or
// ForwardingStrategy failed to find it.
if (!propagated && pitEntry->GetOutgoing ().size () == 0)
{
DidExhaustForwardingOptions (incomingFace, header, packet, pitEntry);
}
}
bool
ForwardingStrategy::WillSendOutInterest (const Ptr<Face> &outgoingFace,
Ptr<InterestHeader> header,
Ptr<pit::Entry> pitEntry)
{
pit::Entry::out_iterator outgoing =
pitEntry->GetOutgoing ().find (outgoingFace);
if (outgoing != pitEntry->GetOutgoing ().end () &&
outgoing->m_retxCount >= pitEntry->GetMaxRetxCount ())
{
NS_LOG_ERROR (outgoing->m_retxCount << " >= " << pitEntry->GetMaxRetxCount ());
return false; // already forwarded before during this retransmission cycle
}
bool ok = outgoingFace->IsBelowLimit ();
if (!ok)
return false;
pitEntry->AddOutgoing (outgoingFace);
return true;
}
void
ForwardingStrategy::DidSendOutInterest (const Ptr<Face> &outgoingFace,
Ptr<InterestHeader> header,
const Ptr<const Packet> &packet,
Ptr<pit::Entry> pitEntry)
{
m_outInterests (header, outgoingFace);
}
void
ForwardingStrategy::DidSendOutData (const Ptr<Face> &face,
Ptr<const ContentObjectHeader> header,
Ptr<const Packet> payload,
const Ptr<const Packet> &packet)
{
}
void
ForwardingStrategy::WillErasePendingInterest (Ptr<pit::Entry> pitEntry)
{
// do nothing for now. may be need to do some logging
}
void
ForwardingStrategy::RemoveFace (Ptr<Face> face)
{
// do nothing here
}
} // namespace ndn
} // namespace ns3