Update README and add contrib dir

contrib/tsn/model/stream-identification-function.cc

@@ -0,0 +1,67 @@
+#include "stream-identification-function.h"
+
+#include "ns3/log.h"
+#include "ns3/uinteger.h"
+#include "ns3/random-variable-stream.h"
+
+namespace ns3
+{
+
+NS_LOG_COMPONENT_DEFINE("StreamIdentificationFunction");
+
+NS_OBJECT_ENSURE_REGISTERED(StreamIdentificationFunction);
+
+TypeId
+StreamIdentificationFunction::GetTypeId()
+{
+    static TypeId tid =
+        TypeId("ns3::StreamIdentificationFunction")
+            .SetParent<Object>()
+            .SetGroupName("tsn")
+            .AddConstructor<StreamIdentificationFunction>()
+            .AddAttribute("MinLatencyOverhead",
+                          "The minimum latency overhead cause by the identification function hardware implementation",
+                          TimeValue(Seconds(0)),
+                          MakeTimeAccessor(&StreamIdentificationFunction::m_minLatencyOverhead),
+                          MakeTimeChecker())
+            .AddAttribute("MaxLatencyOverhead",
+                          "The maximun latency overhead cause by the identification function hardware implementation",
+                          TimeValue(Seconds(0)),
+                          MakeTimeAccessor(&StreamIdentificationFunction::m_maxLatencyOverhead),
+                          MakeTimeChecker());
+    return tid;
+}
+
+
+StreamIdentificationFunction::StreamIdentificationFunction()
+{
+    NS_LOG_FUNCTION(this);
+}
+
+StreamIdentificationFunction::~StreamIdentificationFunction()
+{
+    NS_LOG_FUNCTION(this);
+}
+
+bool
+StreamIdentificationFunction::Match(Ptr<Packet> p)
+{
+  NS_LOG_FUNCTION(this);
+  return false;
+}
+
+void
+StreamIdentificationFunction::GetActiveUpdate(Ptr<Packet> p)
+{
+  NS_LOG_FUNCTION(this);
+}
+
+Time
+StreamIdentificationFunction::GetHardwareLatency()
+{
+  NS_LOG_FUNCTION(this);
+  Ptr<UniformRandomVariable> randVar = CreateObject<UniformRandomVariable>();
+  return NanoSeconds(randVar->GetValue(m_minLatencyOverhead.GetNanoSeconds(), m_maxLatencyOverhead.GetNanoSeconds()));
+}
+
+}