From 43b1ccc7c84dfd4c1a33a81eb74af8b335330fe7 Mon Sep 17 00:00:00 2001
From: Josh Pelkey <jpelkey@gatech.edu>
Date: Wed, 7 Oct 2009 23:06:21 -0400
Subject: [PATCH] Fix for bug 615

---
 src/internet-stack/ipv4-l3-protocol.cc |  2 ++
 src/internet-stack/ipv4-l4-protocol.h  |  1 +
 src/internet-stack/tcp-l4-protocol.cc  | 28 +++++++++++++++++++++++++-
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/internet-stack/ipv4-l3-protocol.cc b/src/internet-stack/ipv4-l3-protocol.cc
index 66b592513..8e95c4f70 100644
--- a/src/internet-stack/ipv4-l3-protocol.cc
+++ b/src/internet-stack/ipv4-l3-protocol.cc
@@ -735,6 +735,8 @@ Ipv4L3Protocol::LocalDeliver (Ptr<const Packet> packet, Ipv4Header const&ip, uin
       switch (status) {
       case Ipv4L4Protocol::RX_OK:
         // fall through
+      case Ipv4L4Protocol::RX_ENDPOINT_CLOSED:
+        // fall through
       case Ipv4L4Protocol::RX_CSUM_FAILED:
         break;
       case Ipv4L4Protocol::RX_ENDPOINT_UNREACH:
diff --git a/src/internet-stack/ipv4-l4-protocol.h b/src/internet-stack/ipv4-l4-protocol.h
index 09c04c3b8..810c5d2af 100644
--- a/src/internet-stack/ipv4-l4-protocol.h
+++ b/src/internet-stack/ipv4-l4-protocol.h
@@ -45,6 +45,7 @@ public:
   enum RxStatus {
     RX_OK,
     RX_CSUM_FAILED,
+    RX_ENDPOINT_CLOSED,
     RX_ENDPOINT_UNREACH
   };
 
diff --git a/src/internet-stack/tcp-l4-protocol.cc b/src/internet-stack/tcp-l4-protocol.cc
index f67234a6b..7b9e87cec 100644
--- a/src/internet-stack/tcp-l4-protocol.cc
+++ b/src/internet-stack/tcp-l4-protocol.cc
@@ -512,7 +512,33 @@ TcpL4Protocol::Receive (Ptr<Packet> packet,
     source.Print (oss);
     oss<<" source port: "<<tcpHeader.GetSourcePort ();
     NS_LOG_LOGIC (oss.str ());
-    return Ipv4L4Protocol::RX_ENDPOINT_UNREACH;
+
+    if (!(tcpHeader.GetFlags () & TcpHeader::RST))
+      {
+        // build a RST packet and send
+        Ptr<Packet> rstPacket = Create<Packet> ();
+        TcpHeader header;
+        if (tcpHeader.GetFlags () & TcpHeader::ACK)
+          {
+            // ACK bit was set
+            header.SetFlags (TcpHeader::RST);
+            header.SetSequenceNumber (header.GetAckNumber ());
+          }
+        else
+          {
+            header.SetFlags (TcpHeader::RST | TcpHeader::ACK);
+            header.SetSequenceNumber (SequenceNumber (0));
+            header.SetAckNumber (header.GetSequenceNumber () + SequenceNumber (1));
+          }
+        header.SetSourcePort (tcpHeader.GetDestinationPort ());
+        header.SetDestinationPort (tcpHeader.GetSourcePort ());
+        SendPacket (rstPacket, header, destination, source);
+        return Ipv4L4Protocol::RX_ENDPOINT_CLOSED;
+      }
+    else
+      {
+        return Ipv4L4Protocol::RX_ENDPOINT_CLOSED;
+      }
   }
   NS_ASSERT_MSG (endPoints.size() == 1 , "Demux returned more than one endpoint");
   NS_LOG_LOGIC ("TcpL4Protocol "<<this<<" forwarding up to endpoint/socket");