From 26eb6ea30de77451438283ddaaecfe19ea9f9c3d Mon Sep 17 00:00:00 2001
From: Tommaso Pecorella <tommaso.pecorella@unifi.it>
Date: Sat, 5 Apr 2025 17:39:51 +0200
Subject: [PATCH] internet: fix ARP cache entries handling

---
 src/internet/model/arp-cache.h        |  3 ---
 src/internet/model/arp-l3-protocol.cc | 22 ++++++++++++++++++----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/internet/model/arp-cache.h b/src/internet/model/arp-cache.h
index e78d903b7..f3a186991 100644
--- a/src/internet/model/arp-cache.h
+++ b/src/internet/model/arp-cache.h
@@ -278,8 +278,6 @@ class ArpCache : public Object
          */
         void UpdateSeen();
 
-<<<<<<< HEAD
-=======
         /**
          * @brief Print this ARP entry to the given output stream
          *
@@ -293,7 +291,6 @@ class ArpCache : public Object
          */
         Time GetTimeout() const;
 
->>>>>>> 04b17e847 (internet: add functions to print an ArpCache::Entry)
       private:
         /**
          * @brief ARP cache entry states
diff --git a/src/internet/model/arp-l3-protocol.cc b/src/internet/model/arp-l3-protocol.cc
index 0cbcb9d65..46539e479 100644
--- a/src/internet/model/arp-l3-protocol.cc
+++ b/src/internet/model/arp-l3-protocol.cc
@@ -309,10 +309,23 @@ ArpL3Protocol::Lookup(Ptr<Packet> packet,
                                     cache,
                                     destination);
             }
+            else if (entry->IsWaitReply())
+            {
+                NS_LOG_LOGIC("node=" << m_node->GetId() << ", entry for " << destination
+                                     << " waiting for a reply -- adding the packet to the queue");
+                if (!entry->UpdateWaitReply(ArpCache::Ipv4PayloadHeaderPair(packet, ipHeader)))
+                {
+                    // add the Ipv4 header for tracing purposes
+                    packet->AddHeader(ipHeader);
+                    m_dropTrace(packet);
+                }
+                return false;
+            }
             else
             {
-                NS_FATAL_ERROR("Test for possibly unreachable code-- please file a bug report, "
-                               "with a test case, if this is ever hit");
+                NS_FATAL_ERROR("Test for possibly unreachable code -- please file a bug report, "
+                               "with a test case - "
+                               << *entry);
             }
         }
         else
@@ -352,8 +365,9 @@ ArpL3Protocol::Lookup(Ptr<Packet> packet,
             }
             else
             {
-                NS_LOG_LOGIC("Test for possibly unreachable code-- please file a bug report, with "
-                             "a test case, if this is ever hit");
+                NS_FATAL_ERROR("Test for possibly unreachable code -- please file a bug report, "
+                               "with a test case - "
+                               << *entry);
             }
         }
     }