From 48079b1184f1fb4ae13955f65ae74ceb463983dc Mon Sep 17 00:00:00 2001
From: "Saswat K. Mishra" <clicksaswat@gmail.com>
Date: Tue, 8 Sep 2015 21:22:49 +0530
Subject: [PATCH 1/2] added support for Ipv6 ndisc cache permanent entries
 added new state PERMANENT new method MarkPermanent () and IsPermanent ()
 moidified Icmpv6L4Protocol::Lookup () to consider new Permanent entries
 modified NdiscCache::PrintCache () to consider new permanent entries as well
 as default case for unknown entry type

---
 src/internet/model/icmpv6-l4-protocol.cc |  4 ++--
 src/internet/model/ndisc-cache.cc        | 22 +++++++++++++++++++++-
 src/internet/model/ndisc-cache.h         | 14 +++++++++++++-
 3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/internet/model/icmpv6-l4-protocol.cc b/src/internet/model/icmpv6-l4-protocol.cc
index a156db7..d7b8ab2 100644
--- a/src/internet/model/icmpv6-l4-protocol.cc
+++ b/src/internet/model/icmpv6-l4-protocol.cc
@@ -1295,7 +1295,7 @@ bool Icmpv6L4Protocol::Lookup (Ipv6Address dst, Ptr<NetDevice> device, Ptr<Ndisc
       NdiscCache::Entry* entry = cache->Lookup (dst);
       if (entry)
         {
-          if (entry->IsReachable () || entry->IsDelay ())
+          if (entry->IsReachable () || entry->IsDelay () || entry->IsPermanent ())
             {
               *hardwareDestination = entry->GetMacAddress ();
               return true;
@@ -1329,7 +1329,7 @@ bool Icmpv6L4Protocol::Lookup (Ptr<Packet> p, Ipv6Address dst, Ptr<NetDevice> de
   NdiscCache::Entry* entry = cache->Lookup (dst);
   if (entry)
     {
-      if (entry->IsReachable () || entry->IsDelay ())
+      if (entry->IsReachable () || entry->IsDelay () || entry->IsPermanent ())
         {
           /* XXX check reachability time */
           /* send packet */
diff --git a/src/internet/model/ndisc-cache.cc b/src/internet/model/ndisc-cache.cc
index 5a9dc0c..b379b23 100644
--- a/src/internet/model/ndisc-cache.cc
+++ b/src/internet/model/ndisc-cache.cc
@@ -187,10 +187,18 @@ void NdiscCache::PrintNdiscCache (Ptr<OutputStreamWrapper> stream)
         {
           *os << " PROBE\n";
         }
-      else
+      else if (i->second->IsStale ())
         {
           *os << " STALE\n";
         }
+      else if (i->second->IsPermanent ())
+	{
+	  *os << " PERMANENT\n";
+	}
+      else
+	{
+	  NS_FATAL_ERROR ("Test for possibly unreachable code-- please file a bug report, with a test case, if this is ever hit");
+	}
     }
 }
 
@@ -495,6 +503,12 @@ void NdiscCache::Entry::MarkDelay ()
   m_state = DELAY;
 }
 
+void NdiscCache::Entry::MarkPermanent ()
+{
+  NS_LOG_FUNCTION_NOARGS ();
+  m_state = PERMANENT;
+}
+
 bool NdiscCache::Entry::IsStale () const
 {
   NS_LOG_FUNCTION_NOARGS ();
@@ -525,6 +539,12 @@ bool NdiscCache::Entry::IsProbe () const
   return (m_state == PROBE);
 }
 
+bool NdiscCache::Entry::IsPermanent () const
+{
+  NS_LOG_FUNCTION_NOARGS ();
+  return (m_state == PERMANENT);
+}
+
 Address NdiscCache::Entry::GetMacAddress () const
 {
   NS_LOG_FUNCTION_NOARGS ();
diff --git a/src/internet/model/ndisc-cache.h b/src/internet/model/ndisc-cache.h
index 81eca93..951e02a 100644
--- a/src/internet/model/ndisc-cache.h
+++ b/src/internet/model/ndisc-cache.h
@@ -185,6 +185,11 @@ public:
     void MarkDelay ();
 
     /**
+     * \brief Change the state to this entry to PERMANENT.
+     */
+    void MarkPermanent ();
+
+    /**
      * \brief Add a packet (or replace old value) in the queue.
      * \param p packet to add
      */
@@ -226,6 +231,12 @@ public:
     bool IsProbe () const;
 
     /**
+     * \brief Is the entry PERMANENT
+     * \return true if the entry is in PERMANENT state, false otherwise
+     */
+    bool IsPermanent () const;
+
+    /**
      * \brief Get the MAC address of this entry.
      * \return the L2 address
      */
@@ -328,7 +339,8 @@ private:
       REACHABLE, /**< Mapping exists between IPv6 and L2 addresses */
       STALE, /**< Mapping is stale */
       DELAY, /**< Try to wait contact from remote host */
-      PROBE /**< Try to contact IPv6 address to know again its L2 address */
+      PROBE, /**< Try to contact IPv6 address to know again its L2 address */
+      PERMANENT /**< Permanent Mapping exists between IPv6 and L2 addresses */
     };
 
     /**
-- 
2.1.0


From dc1cb3d495581c5b8de750c535e1b0cb818223ec Mon Sep 17 00:00:00 2001
From: "Saswat K. Mishra" <clicksaswat@gmail.com>
Date: Wed, 16 Sep 2015 23:40:12 +0530
Subject: [PATCH 2/2] modified a few places where permanet entries were being
 igonred

---
 src/internet/model/icmpv6-l4-protocol.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/internet/model/icmpv6-l4-protocol.cc b/src/internet/model/icmpv6-l4-protocol.cc
index d7b8ab2..37a4840 100644
--- a/src/internet/model/icmpv6-l4-protocol.cc
+++ b/src/internet/model/icmpv6-l4-protocol.cc
@@ -401,7 +401,7 @@ void Icmpv6L4Protocol::ReceiveLLA (Icmpv6OptionLinkLayerAddress lla, Ipv6Address
             }
           else
             {
-              if (!entry->IsReachable ())
+              if (!entry->IsReachable () || !entry->IsPermanent ())
                 {
                   entry->StopNudTimer ();
                   waiting = entry->MarkReachable (lla.GetAddress ());
@@ -708,7 +708,7 @@ void Icmpv6L4Protocol::HandleNA (Ptr<Packet> packet, Ipv6Address const &src, Ipv
 
               if (naHeader.GetFlagS ())
                 {
-                  if (!entry->IsReachable ())
+                  if (!entry->IsReachable () || !entry->IsPermanent ())
                     {
                       if (entry->IsProbe ())
                         {
-- 
2.1.0