Serious refactoring. Making forwarding strategy really modular
diff --git a/model/forwarding-strategy/ccnx-forwarding-strategy.cc b/model/forwarding-strategy/ccnx-forwarding-strategy.cc
index 9cdfa4d..3d6f3de 100644
--- a/model/forwarding-strategy/ccnx-forwarding-strategy.cc
+++ b/model/forwarding-strategy/ccnx-forwarding-strategy.cc
@@ -67,26 +67,20 @@
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
- .AddTraceSource ("OutNacks", "OutNacks", MakeTraceSourceAccessor (&CcnxForwardingStrategy::m_outNacks))
- .AddTraceSource ("InNacks", "InNacks", MakeTraceSourceAccessor (&CcnxForwardingStrategy::m_inNacks))
- .AddTraceSource ("DropNacks", "DropNacks", MakeTraceSourceAccessor (&CcnxForwardingStrategy::m_dropNacks))
-
- ////////////////////////////////////////////////////////////////////
- ////////////////////////////////////////////////////////////////////
-
.AddTraceSource ("OutData", "OutData", MakeTraceSourceAccessor (&CcnxForwardingStrategy::m_outData))
.AddTraceSource ("InData", "InData", MakeTraceSourceAccessor (&CcnxForwardingStrategy::m_inData))
.AddTraceSource ("DropData", "DropData", MakeTraceSourceAccessor (&CcnxForwardingStrategy::m_dropData))
- .AddAttribute ("EnableNACKs", "Enabling support of NACKs",
- BooleanValue (false),
- MakeBooleanAccessor (&CcnxForwardingStrategy::m_nacksEnabled),
- MakeBooleanChecker ())
.AddAttribute ("CacheUnsolicitedData", "Cache overheard data that have not been requested",
BooleanValue (false),
MakeBooleanAccessor (&CcnxForwardingStrategy::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 (&CcnxForwardingStrategy::m_detectRetransmissions),
+ MakeBooleanChecker ())
;
return tid;
}
@@ -139,16 +133,17 @@
if (pitEntry == 0)
{
pitEntry = m_pit->Create (header);
+ if (pitEntry != 0)
+ {
+ DidCreatePitEntry (incomingFace, header, packet, pitEntry);
+ }
+ else
+ {
+ FailedToCreatePitEntry (incomingFace, header, packet);
+ return;
+ }
}
- if (pitEntry == 0)
- {
- // if it is still not created, then give up processing
- m_dropInterests (header, incomingFace);
- return;
- }
-
- bool isNew = pitEntry->GetIncoming ().size () == 0 && pitEntry->GetOutgoing ().size () == 0;
bool isDuplicated = true;
if (!pitEntry->IsNonceSeen (header->GetNonce ()))
{
@@ -156,61 +151,9 @@
isDuplicated = false;
}
- NS_LOG_FUNCTION (header->GetName () << header->GetNonce () << boost::cref (*incomingFace) << isDuplicated);
-
- /////////////////////////////////////////////////////////////////////////////////////////
- /////////////////////////////////////////////////////////////////////////////////////////
- /////////////////////////////////////////////////////////////////////////////////////////
- // //
- // !!!! IMPORTANT CHANGE !!!! Duplicate interests will create incoming face entry !!!! //
- // //
- /////////////////////////////////////////////////////////////////////////////////////////
- /////////////////////////////////////////////////////////////////////////////////////////
- /////////////////////////////////////////////////////////////////////////////////////////
-
- // Data is not in cache
- CcnxPitEntry::in_iterator inFace = pitEntry->GetIncoming ().find (incomingFace);
- CcnxPitEntry::out_iterator outFace = pitEntry->GetOutgoing ().find (incomingFace);
-
- bool isRetransmitted = false;
-
- if (inFace != pitEntry->GetIncoming ().end ())
- {
- // CcnxPitEntryIncomingFace.m_arrivalTime keeps track arrival time of the first packet... why?
-
- isRetransmitted = true;
- // this is almost definitely a retransmission. But should we trust the user on that?
- }
- else
- {
- inFace = pitEntry->AddIncoming (incomingFace);
- }
- //////////////////////////////////////////////////////////////////////////////////
- //////////////////////////////////////////////////////////////////////////////////
- //////////////////////////////////////////////////////////////////////////////////
-
if (isDuplicated)
{
- NS_LOG_DEBUG ("Received duplicatie interest on " << *incomingFace);
- m_dropInterests (header, incomingFace);
-
- /**
- * This condition will handle "routing" loops and also recently satisfied interests.
- * Every time interest is satisfied, PIT entry (with empty incoming and outgoing faces)
- * is kept for another small chunk of time.
- */
-
- if (m_nacksEnabled)
- {
- NS_LOG_DEBUG ("Sending NACK_LOOP");
- header->SetNack (CcnxInterestHeader::NACK_LOOP);
- Ptr<Packet> nack = Create<Packet> ();
- nack->AddHeader (*header);
-
- incomingFace->Send (nack);
- m_outNacks (header, incomingFace);
- }
-
+ DidReceiveDuplicateInterest (incomingFace, header, packet, pitEntry);
return;
}
@@ -221,64 +164,25 @@
if (contentObject != 0)
{
NS_ASSERT (contentObjectHeader != 0);
- NS_LOG_LOGIC("Found in cache");
- OnDataDelayed (contentObjectHeader, payload, contentObject);
+ pitEntry->AddIncoming (incomingFace/*, Seconds (1.0)*/);
+ SatisfyPendingInterest (0, contentObjectHeader, payload, contentObject, pitEntry);
return;
}
- // update PIT entry lifetime
- pitEntry->UpdateLifetime (header->GetInterestLifetime ());
-
- if (outFace != pitEntry->GetOutgoing ().end ())
+ if (ShouldSuppressIncomingInterest (incomingFace, pitEntry))
{
- 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
+ pitEntry->AddIncoming (incomingFace/*, header->GetInterestLifetime ()*/);
+ // update PIT entry lifetime
+ pitEntry->UpdateLifetime (header->GetInterestLifetime ());
- // 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, CcnxFibFaceMetric::NDN_FIB_YELLOW);
- // StaticCast<CcnxFibImpl> (m_fib)->modify(pitEntry->GetFibEntry (),
- // ll::bind (&CcnxFibEntry::UpdateStatus,
- // ll::_1, incomingFace, CcnxFibFaceMetric::NDN_FIB_YELLOW));
- }
- else
- if (!isNew && !isRetransmitted)
- {
- // Suppress this interest if we're still expecting data from some other face
- NS_LOG_DEBUG ("Suppress interests");
- m_dropInterests (header, incomingFace);
- return;
- }
-
- /////////////////////////////////////////////////////////////////////
- // Propagate
- /////////////////////////////////////////////////////////////////////
-
- bool propagated = PropagateInterest (pitEntry, incomingFace, header, packet);
-
- if (!propagated && isRetransmitted) //give another chance if retransmitted
- {
- // increase max number of allowed retransmissions
- pitEntry->IncreaseAllowedRetxCount ();
-
- // try again
- propagated = PropagateInterest (pitEntry, incomingFace, header, packet);
- }
-
- // 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)
- {
- NS_LOG_DEBUG ("Not propagated");
+ // Suppress this interest if we're still expecting data from some other face
+ NS_LOG_DEBUG ("Suppress interests");
m_dropInterests (header, incomingFace);
- GiveUpInterest (pitEntry, header);
+ return;
}
+
+ PropagateInterest (incomingFace, header, packet, pitEntry);
}
void
@@ -290,205 +194,220 @@
NS_LOG_FUNCTION (incomingFace << header->GetName () << payload << packet);
m_inData (header, payload, incomingFace);
- // 1. Lookup PIT entry
+ // Lookup PIT entry
Ptr<CcnxPitEntry> pitEntry = m_pit->Lookup (*header);
- if (pitEntry != 0)
+ if (pitEntry == 0)
{
- // Note that with MultiIndex we need to modify entries indirectly
-
- CcnxPitEntry::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);
- // StaticCast<CcnxFibImpl> (m_fib)->modify (pitEntry->GetFibEntry (),
- // ll::bind (&CcnxFibEntry::UpdateFaceRtt,
- // ll::_1,
- // incomingFace,
- // Simulator::Now () - out->m_sendTime));
- }
- else
- {
- // Unsolicited data, but we're interested in it... should we get it?
- // Potential hole for attacks
-
- if (m_cacheUnsolicitedData)
- {
- // Optimistically add or update entry in the content store
- m_contentStore->Add (header, payload);
- }
- else
- {
- NS_LOG_ERROR ("PIT entry for "<< header->GetName ()<<" is valid, "
- "but outgoing entry for interface "<< boost::cref(*incomingFace) <<" doesn't exist\n");
- }
- // ignore unsolicited data
- return;
- }
-
- // Update metric status for the incoming interface in the corresponding FIB entry
- pitEntry->GetFibEntry ()->UpdateStatus (incomingFace, CcnxFibFaceMetric::NDN_FIB_GREEN);
- // StaticCast<CcnxFibImpl>(m_fib)->modify (pitEntry->GetFibEntry (),
- // ll::bind (&CcnxFibEntry::UpdateStatus, ll::_1,
- // incomingFace, CcnxFibFaceMetric::NDN_FIB_GREEN));
-
+ DidReceiveUnsolicitedData (incomingFace, header, payload);
+ return;
+ }
+ else
+ {
// Add or update entry in the content store
m_contentStore->Add (header, payload);
-
- pitEntry->RemoveIncoming (incomingFace);
-
- if (pitEntry->GetIncoming ().size () == 0)
- {
- // Set pruning timout on PIT entry (instead of deleting the record)
- m_pit->MarkErased (pitEntry);
- }
- else
- {
- OnDataDelayed (header, payload, packet);
- }
}
- else
+
+ while (pitEntry != 0)
{
- NS_LOG_DEBUG ("Pit entry not found");
- 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);
- }
- return; // do not process unsoliced data packets
+ // 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
+CcnxForwardingStrategy::DidReceiveDuplicateInterest (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxInterestHeader> &header,
+ const Ptr<const Packet> &packet,
+ Ptr<CcnxPitEntry> pitEntry)
+{
+ NS_LOG_FUNCTION (this << *incomingFace);
+ /////////////////////////////////////////////////////////////////////////////////////////
+ // //
+ // !!!! IMPORTANT CHANGE !!!! Duplicate interests will create incoming face entry !!!! //
+ // //
+ /////////////////////////////////////////////////////////////////////////////////////////
+ pitEntry->AddIncoming (incomingFace);
+ m_dropInterests (header, incomingFace);
+}
+
+void
+CcnxForwardingStrategy::DidExhaustForwardingOptions (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxInterestHeader> header,
+ const Ptr<const Packet> &packet,
+ Ptr<CcnxPitEntry> pitEntry)
+{
+ NS_LOG_FUNCTION (this << *incomingFace);
+ m_dropInterests (header, incomingFace);
+}
+
+void
+CcnxForwardingStrategy::FailedToCreatePitEntry (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxInterestHeader> header,
+ const Ptr<const Packet> &packet)
+{
+ NS_LOG_FUNCTION (this);
+ m_dropInterests (header, incomingFace);
+}
+
+void
+CcnxForwardingStrategy::DidCreatePitEntry (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxInterestHeader> header,
+ const Ptr<const Packet> &packet,
+ Ptr<CcnxPitEntry> pitEntrypitEntry)
+{
+}
+
bool
-CcnxForwardingStrategy::PropagateInterestViaGreen (Ptr<CcnxPitEntry> pitEntry,
- const Ptr<CcnxFace> &incomingFace,
- Ptr<CcnxInterestHeader> &header,
- const Ptr<const Packet> &packet)
+CcnxForwardingStrategy::DetectRetransmittedInterest (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxPitEntry> pitEntry)
{
- NS_LOG_FUNCTION (this);
- NS_ASSERT_MSG (m_pit != 0, "PIT should be aggregated with forwarding strategy");
+ CcnxPitEntry::in_iterator inFace = pitEntry->GetIncoming ().find (incomingFace);
- int propagatedCount = 0;
+ bool isRetransmitted = false;
- BOOST_FOREACH (const CcnxFibFaceMetric &metricFace, pitEntry->GetFibEntry ()->m_faces.get<i_metric> ())
+ if (inFace != pitEntry->GetIncoming ().end ())
{
- if (metricFace.m_status == CcnxFibFaceMetric::NDN_FIB_RED ||
- metricFace.m_status == CcnxFibFaceMetric::NDN_FIB_YELLOW)
- break; //propagate only to green faces
-
- if (pitEntry->GetIncoming ().find (metricFace.m_face) != pitEntry->GetIncoming ().end ())
- continue; // don't forward to face that we received interest from
-
- CcnxPitEntryOutgoingFaceContainer::type::iterator outgoing =
- pitEntry->GetOutgoing ().find (metricFace.m_face);
-
- if (outgoing != pitEntry->GetOutgoing ().end () &&
- outgoing->m_retxCount >= pitEntry->GetMaxRetxCount ())
- {
- NS_LOG_DEBUG ("retxCount: " << outgoing->m_retxCount << ", maxRetxCount: " << pitEntry->GetMaxRetxCount ());
- continue;
- }
-
- bool faceAvailable = metricFace.m_face->IsBelowLimit ();
- if (!faceAvailable) // huh...
- {
- // let's try different green face
- continue;
- }
-
- pitEntry->AddOutgoing (metricFace.m_face);
-
- Ptr<Packet> packetToSend = packet->Copy ();
-
- //transmission
- metricFace.m_face->Send (packetToSend);
- m_outInterests (header, metricFace.m_face);
-
- propagatedCount++;
- break; // propagate only one interest
+ // this is almost definitely a retransmission. But should we trust the user on that?
+ isRetransmitted = true;
}
- return propagatedCount > 0;
+ return isRetransmitted;
}
void
-CcnxForwardingStrategy::OnDataDelayed (Ptr<const CcnxContentObjectHeader> header,
- Ptr<const Packet> payload,
- const Ptr<const Packet> &packet)
+CcnxForwardingStrategy::SatisfyPendingInterest (const Ptr<CcnxFace> &incomingFace,
+ Ptr<const CcnxContentObjectHeader> header,
+ Ptr<const Packet> payload,
+ const Ptr<const Packet> &packet,
+ Ptr<CcnxPitEntry> pitEntry)
{
- // 1. Lookup PIT entry
- Ptr<CcnxPitEntry> pitEntry = m_pit->Lookup (*header);
- if (pitEntry != 0)
+ if (incomingFace != 0)
+ pitEntry->RemoveIncoming (incomingFace);
+
+ //satisfy all pending incoming Interests
+ BOOST_FOREACH (const CcnxPitEntryIncomingFace &incoming, pitEntry->GetIncoming ())
{
- //satisfy all pending incoming Interests
- BOOST_FOREACH (const CcnxPitEntryIncomingFace &incoming, pitEntry->GetIncoming ())
- {
- incoming.m_face->Send (packet->Copy ());
- m_outData (header, payload, false, incoming.m_face);
- NS_LOG_DEBUG ("Satisfy " << *incoming.m_face);
+ incoming.m_face->Send (packet->Copy ());
+ m_outData (header, payload, false, incoming.m_face);
+ NS_LOG_DEBUG ("Satisfy " << *incoming.m_face);
- // successfull forwarded data trace
- }
+ // successfull forwarded data trace
+ }
- if (pitEntry->GetIncoming ().size () > 0)
- {
- // All incoming interests are satisfied. Remove them
- pitEntry->ClearIncoming ();
+ // All incoming interests are satisfied. Remove them
+ pitEntry->ClearIncoming ();
- // Remove all outgoing faces
- pitEntry->ClearOutgoing ();
+ // Remove all outgoing faces
+ pitEntry->ClearOutgoing ();
- // Set pruning timout on PIT entry (instead of deleting the record)
- m_pit->MarkErased (pitEntry);
- }
+ // Set pruning timout on PIT entry (instead of deleting the record)
+ m_pit->MarkErased (pitEntry);
+}
+
+void
+CcnxForwardingStrategy::DidReceiveUnsolicitedData (const Ptr<CcnxFace> &incomingFace,
+ Ptr<const CcnxContentObjectHeader> header,
+ Ptr<const Packet> payload)
+{
+ if (m_cacheUnsolicitedData)
+ {
+ // Optimistically add or update entry in the content store
+ m_contentStore->Add (header, payload);
}
else
{
- NS_LOG_DEBUG ("Pit entry not found (was satisfied and removed before)");
- return; // do not process unsoliced data packets
+ // 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
-CcnxForwardingStrategy::GiveUpInterest (Ptr<CcnxPitEntry> pitEntry,
- Ptr<CcnxInterestHeader> header)
+CcnxForwardingStrategy::WillSatisfyPendingInterest (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxPitEntry> pitEntry)
{
- NS_LOG_FUNCTION (this);
-
- if (m_nacksEnabled)
+ CcnxPitEntry::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 ())
{
- Ptr<Packet> packet = Create<Packet> ();
- header->SetNack (CcnxInterestHeader::NACK_GIVEUP_PIT);
- packet->AddHeader (*header);
-
- BOOST_FOREACH (const CcnxPitEntryIncomingFace &incoming, pitEntry->GetIncoming ())
- {
- NS_LOG_DEBUG ("Send NACK for " << boost::cref (header->GetName ()) << " to " << boost::cref (*incoming.m_face));
- incoming.m_face->Send (packet->Copy ());
-
- m_outNacks (header, incoming.m_face);
- }
-
- // All incoming interests cannot be satisfied. Remove them
- pitEntry->ClearIncoming ();
-
- // Remove also outgoing
- pitEntry->ClearOutgoing ();
-
- // Set pruning timout on PIT entry (instead of deleting the record)
- m_pit->MarkErased (pitEntry);
- }
+ pitEntry->GetFibEntry ()->UpdateFaceRtt (incomingFace, Simulator::Now () - out->m_sendTime);
+ }
}
+bool
+CcnxForwardingStrategy::ShouldSuppressIncomingInterest (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxPitEntry> 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, CcnxFibFaceMetric::NDN_FIB_YELLOW);
+ }
+ else
+ if (!isNew && !isRetransmitted)
+ {
+ return true;
+ }
+
+ return false;
+}
+
+void
+CcnxForwardingStrategy::PropagateInterest (const Ptr<CcnxFace> &incomingFace,
+ Ptr<CcnxInterestHeader> &header,
+ const Ptr<const Packet> &packet,
+ Ptr<CcnxPitEntry> 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);
+ }
+}
} //namespace ns3