Update README and add contrib dir

contrib/tsn/model/frer-base-recovery-function.h

@@ -0,0 +1,68 @@
+#ifndef FRER_BASE_RECOVERY_FUNCTION_H
+#define FRER_BASE_RECOVERY_FUNCTION_H
+
+#include "ns3/object.h"
+
+#include "ns3/nstime.h"
+
+
+namespace ns3
+{
+
+class BaseRecoveryFunction : public Object
+{
+  public:
+    /**
+     * \brief Get the TypeId
+     *
+     * \return The TypeId for this class
+     */
+    static TypeId GetTypeId();
+
+    /**
+     * \brief Create a BaseRecoveryFunction
+     */
+    BaseRecoveryFunction();
+
+    /**
+     * Destroy a BaseRecoveryFunction
+     *
+     * This is the destructor for the BaseRecoveryFunction.
+     */
+    ~BaseRecoveryFunction();
+
+    // Delete copy constructor and assignment operator to avoid misuse
+    BaseRecoveryFunction& operator=(const BaseRecoveryFunction&) = delete;
+    BaseRecoveryFunction(const BaseRecoveryFunction&) = delete;
+
+    uint GetFrerCpsSeqRcvyPassedPackets();
+    uint GetFrerCpsSeqRcvyDiscardedPackets();
+
+    void resetRecoveryFunction();
+
+    virtual bool DoRecovery(uint16_t seqNumber);
+
+  protected:
+    uint m_recovSeqSpace = 65536;                                   //802.1CB-2017 : 7.4.3.2.1
+    uint16_t m_recovSeqNum = 0;                                   //802.1CB-2017 : 7.4.3.2.3
+    bool m_takeAny = true;                                        //802.1CB-2017 : 7.4.3.2.6
+    Time m_frerSeqRcvyResetMSec;                                  //802.1CB-2017 : 10.4.1.7
+    bool m_frerSeqRcvyIndividualRecovery = false;                 //802.1CB-2017 : 10.4.1.10
+
+    uint m_frerCpsSeqRcvyOutOfOrderPackets = 0;                 //802.1CB-2017 : 10.8.3
+    uint m_frerCpsSeqRcvyPassedPackets = 0;                     //802.1CB-2017 : 10.8.5
+    uint m_frerCpsSeqRcvyDiscardedPackets = 0;                  //802.1CB-2017 : 10.8.6
+
+    Time m_frerMinSeqRcvyResetMSec;
+    Time m_frerMaxSeqRcvyResetMSec;
+
+    EventId m_resetEvent;
+
+
+  private:
+
+
+};
+
+}
+#endif /* FRER_BASE_RECOVERY_FUNCTION_H */