internet: added last acked seq in tcp

src/internet/model/tcp-socket-base.cc

@@ -234,6 +234,7 @@ TcpSocketState::TcpSocketState (void)
     m_initialCWnd (0),
     m_initialSsThresh (0),
     m_segmentSize (0),
+    m_lastAckedSeq (0),
     m_congState (CA_OPEN),
     m_highTxMark (0),
     // Change m_nextTxSequence for non-zero initial sequence number
@@ -248,6 +249,7 @@ TcpSocketState::TcpSocketState (const TcpSocketState &other)
     m_initialCWnd (other.m_initialCWnd),
     m_initialSsThresh (other.m_initialSsThresh),
     m_segmentSize (other.m_segmentSize),
+    m_lastAckedSeq (other.m_lastAckedSeq),
     m_congState (other.m_congState),
     m_highTxMark (other.m_highTxMark),
     m_nextTxSequence (other.m_nextTxSequence)
@@ -1464,6 +1466,8 @@ TcpSocketBase::ReceivedAck (Ptr<Packet> packet, const TcpHeader& tcpHeader)
                 " SND.UNA=" << m_txBuffer->HeadSequence () <<
                 " SND.NXT=" << m_tcb->m_nextTxSequence);
 
+  m_tcb->m_lastAckedSeq = ackNumber;
+
   if (ackNumber == m_txBuffer->HeadSequence ()
       && ackNumber < m_tcb->m_nextTxSequence
       && packet->GetSize () == 0)

src/internet/model/tcp-socket-base.h

@@ -158,6 +158,7 @@ public:
 
   // Segment
   uint32_t               m_segmentSize;     //!< Segment size
+  SequenceNumber32       m_lastAckedSeq;    //!< Last sequence ACKed
 
   TracedValue<TcpCongState_t> m_congState;    //!< State in the Congestion state machine
   TracedValue<SequenceNumber32> m_highTxMark; //!< Highest seqno ever sent, regardless of ReTx