MdeModulePkg: Move to new location

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Guo Mang <mang.guo@intel.com>

1 files changed, 0 insertions, 1478 deletions

diff --git a/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Input.c b/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Input.c
deleted file mode 100644
index 1000538f87..0000000000
--- a/MdeModulePkg/Universal/Network/Tcp4Dxe/Tcp4Input.c
+++ /dev/null
@@ -1,1478 +0,0 @@
-/** @file

-  TCP input process routines.

-

-Copyright (c) 2005 - 2016, Intel Corporation. All rights reserved.<BR>

-This program and the accompanying materials

-are licensed and made available under the terms and conditions of the BSD License

-which accompanies this distribution.  The full text of the license may be found at

-http://opensource.org/licenses/bsd-license.php<BR>

-

-THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,

-WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

-

-**/

-

-

-#include "Tcp4Main.h"

-

-

-/**

-  Check whether the sequence number of the incoming segment is acceptable.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Seg      Pointer to the incoming segment.

-

-  @retval 1       The sequence number is acceptable.

-  @retval 0       The sequence number is not acceptable.

-

-**/

-INTN

-TcpSeqAcceptable (

-  IN TCP_CB  *Tcb,

-  IN TCP_SEG *Seg

-  )

-{

-  return (TCP_SEQ_LEQ (Tcb->RcvNxt, Seg->End) &&

-          TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2 + Tcb->RcvWnd));

-}

-

-

-/**

-  NewReno fast recovery, RFC3782.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Seg      Segment that triggers the fast recovery.

-

-**/

-VOID

-TcpFastRecover (

-  IN OUT TCP_CB  *Tcb,

-  IN     TCP_SEG *Seg

-  )

-{

-  UINT32  FlightSize;

-  UINT32  Acked;

-

-  //

-  // Step 1: Three duplicate ACKs and not in fast recovery

-  //

-  if (Tcb->CongestState != TCP_CONGEST_RECOVER) {

-

-    //

-    // Step 1A: Invoking fast retransmission.

-    //

-    FlightSize        = TCP_SUB_SEQ (Tcb->SndNxt, Tcb->SndUna);

-

-    Tcb->Ssthresh     = MAX (FlightSize >> 1, (UINT32) (2 * Tcb->SndMss));

-    Tcb->Recover      = Tcb->SndNxt;

-

-    Tcb->CongestState = TCP_CONGEST_RECOVER;

-    TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);

-

-    //

-    // Step 2: Entering fast retransmission

-    //

-    TcpRetransmit (Tcb, Tcb->SndUna);

-    Tcb->CWnd = Tcb->Ssthresh + 3 * Tcb->SndMss;

-

-    DEBUG ((EFI_D_NET, "TcpFastRecover: enter fast retransmission"

-      " for TCB %p, recover point is %d\n", Tcb, Tcb->Recover));

-    return;

-  }

-

-  //

-  // During fast recovery, execute Step 3, 4, 5 of RFC3782

-  //

-  if (Seg->Ack == Tcb->SndUna) {

-

-    //

-    // Step 3: Fast Recovery,

-    // If this is a duplicated ACK, increse Cwnd by SMSS.

-    //

-

-    // Step 4 is skipped here only to be executed later

-    // by TcpToSendData

-    //

-    Tcb->CWnd += Tcb->SndMss;

-    DEBUG ((EFI_D_NET, "TcpFastRecover: received another"

-      " duplicated ACK (%d) for TCB %p\n", Seg->Ack, Tcb));

-

-  } else {

-

-    //

-    // New data is ACKed, check whether it is a

-    // full ACK or partial ACK

-    //

-    if (TCP_SEQ_GEQ (Seg->Ack, Tcb->Recover)) {

-

-      //

-      // Step 5 - Full ACK:

-      // deflate the congestion window, and exit fast recovery

-      //

-      FlightSize        = TCP_SUB_SEQ (Tcb->SndNxt, Tcb->SndUna);

-

-      Tcb->CWnd         = MIN (Tcb->Ssthresh, FlightSize + Tcb->SndMss);

-

-      Tcb->CongestState = TCP_CONGEST_OPEN;

-      DEBUG ((EFI_D_NET, "TcpFastRecover: received a full ACK(%d)"

-        " for TCB %p, exit fast recovery\n", Seg->Ack, Tcb));

-

-    } else {

-

-      //

-      // Step 5 - Partial ACK:

-      // fast retransmit the first unacknowledge field

-      // , then deflate the CWnd

-      //

-      TcpRetransmit (Tcb, Seg->Ack);

-      Acked = TCP_SUB_SEQ (Seg->Ack, Tcb->SndUna);

-

-      //

-      // Deflate the CWnd by the amount of new data

-      // ACKed by SEG.ACK. If more than one SMSS data

-      // is ACKed, add back SMSS byte to CWnd after

-      //

-      if (Acked >= Tcb->SndMss) {

-        Acked -= Tcb->SndMss;

-

-      }

-

-      Tcb->CWnd -= Acked;

-

-      DEBUG ((EFI_D_NET, "TcpFastRecover: received a partial"

-        " ACK(%d) for TCB %p\n", Seg->Ack, Tcb));

-

-    }

-  }

-}

-

-

-/**

-  NewReno fast loss recovery, RFC3792.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Seg      Segment that triggers the fast loss recovery.

-

-**/

-VOID

-TcpFastLossRecover (

-  IN OUT TCP_CB  *Tcb,

-  IN     TCP_SEG *Seg

-  )

-{

-  if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {

-

-    //

-    // New data is ACKed, check whether it is a

-    // full ACK or partial ACK

-    //

-    if (TCP_SEQ_GEQ (Seg->Ack, Tcb->LossRecover)) {

-

-      //

-      // Full ACK: exit the loss recovery.

-      //

-      Tcb->LossTimes    = 0;

-      Tcb->CongestState = TCP_CONGEST_OPEN;

-

-      DEBUG ((EFI_D_NET, "TcpFastLossRecover: received a "

-        "full ACK(%d) for TCB %p\n", Seg->Ack, Tcb));

-

-    } else {

-

-      //

-      // Partial ACK:

-      // fast retransmit the first unacknowledge field.

-      //

-      TcpRetransmit (Tcb, Seg->Ack);

-      DEBUG ((EFI_D_NET, "TcpFastLossRecover: received a "

-        "partial ACK(%d) for TCB %p\n", Seg->Ack, Tcb));

-    }

-  }

-}

-

-

-/**

-  Compute the RTT as specified in RFC2988.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Measure  Currently measured RTT in heart beats.

-

-**/

-VOID

-TcpComputeRtt (

-  IN OUT TCP_CB *Tcb,

-  IN     UINT32 Measure

-  )

-{

-  INT32 Var;

-

-  //

-  // Step 2.3: Compute the RTO for subsequent RTT measurement.

-  //

-  if (Tcb->SRtt != 0) {

-

-    Var = Tcb->SRtt - (Measure << TCP_RTT_SHIFT);

-

-    if (Var < 0) {

-      Var = -Var;

-    }

-

-    Tcb->RttVar = (3 * Tcb->RttVar + Var) >> 2;

-    Tcb->SRtt   = 7 * (Tcb->SRtt >> 3) + Measure;

-

-  } else {

-    //

-    // Step 2.2: compute the first RTT measure

-    //

-    Tcb->SRtt   = Measure << TCP_RTT_SHIFT;

-    Tcb->RttVar = Measure << (TCP_RTT_SHIFT - 1);

-  }

-

-  Tcb->Rto = (Tcb->SRtt + MAX (8, 4 * Tcb->RttVar)) >> TCP_RTT_SHIFT;

-

-  //

-  // Step 2.4: Limit the RTO to at least 1 second

-  // Step 2.5: Limit the RTO to a maxium value that

-  // is at least 60 second

-  //

-  if (Tcb->Rto < TCP_RTO_MIN) {

-    Tcb->Rto = TCP_RTO_MIN;

-

-  } else if (Tcb->Rto > TCP_RTO_MAX) {

-    Tcb->Rto = TCP_RTO_MAX;

-

-  }

-

-  DEBUG ((EFI_D_NET, "TcpComputeRtt: new RTT for TCB %p"

-    " computed SRTT: %d RTTVAR: %d RTO: %d\n",

-    Tcb, Tcb->SRtt, Tcb->RttVar, Tcb->Rto));

-

-}

-

-

-/**

-  Trim the data, SYN and FIN to fit into the window defined by Left and Right.

-

-  @param  Nbuf     Buffer that contains received TCP segment without IP header.

-  @param  Left     The sequence number of the window's left edge.

-  @param  Right    The sequence number of the window's right edge.

-

-**/

-VOID

-TcpTrimSegment (

-  IN NET_BUF   *Nbuf,

-  IN TCP_SEQNO Left,

-  IN TCP_SEQNO Right

-  )

-{

-  TCP_SEG   *Seg;

-  TCP_SEQNO Urg;

-  UINT32    Drop;

-

-  Seg = TCPSEG_NETBUF (Nbuf);

-

-  //

-  // If the segment is completely out of window,

-  // truncate every thing, include SYN and FIN.

-  //

-  if (TCP_SEQ_LEQ (Seg->End, Left) || TCP_SEQ_LEQ (Right, Seg->Seq)) {

-

-    TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_SYN);

-    TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_FIN);

-

-    Seg->Seq = Seg->End;

-    NetbufTrim (Nbuf, Nbuf->TotalSize, NET_BUF_HEAD);

-    return;

-  }

-

-  //

-  // Adjust the buffer header

-  //

-  if (TCP_SEQ_LT (Seg->Seq, Left)) {

-

-    Drop      = TCP_SUB_SEQ (Left, Seg->Seq);

-    Urg       = Seg->Seq + Seg->Urg;

-    Seg->Seq  = Left;

-

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {

-      TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_SYN);

-      Drop--;

-    }

-

-    //

-    // Adjust the urgent point

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG)) {

-

-      if (TCP_SEQ_LT (Urg, Seg->Seq)) {

-

-        TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);

-      } else {

-        Seg->Urg = (UINT16) TCP_SUB_SEQ (Urg, Seg->Seq);

-      }

-    }

-

-    if (Drop != 0) {

-      NetbufTrim (Nbuf, Drop, NET_BUF_HEAD);

-    }

-  }

-

-  //

-  // Adjust the buffer tail

-  //

-  if (TCP_SEQ_GT (Seg->End, Right)) {

-

-    Drop      = TCP_SUB_SEQ (Seg->End, Right);

-    Seg->End  = Right;

-

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {

-      TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_FIN);

-      Drop--;

-    }

-

-    if (Drop != 0) {

-      NetbufTrim (Nbuf, Drop, NET_BUF_TAIL);

-    }

-  }

-

-  ASSERT (TcpVerifySegment (Nbuf) != 0);

-}

-

-

-/**

-  Trim off the data outside the tcb's receive window.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Nbuf     Pointer to the NET_BUF containing the received tcp segment.

-

-**/

-VOID

-TcpTrimInWnd (

-  IN TCP_CB  *Tcb,

-  IN NET_BUF *Nbuf

-  )

-{

-  TcpTrimSegment (Nbuf, Tcb->RcvNxt, Tcb->RcvWl2 + Tcb->RcvWnd);

-}

-

-

-/**

-  Process the data and FIN flag, check whether to deliver

-  data to the socket layer.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-

-  @retval 0        No error occurred to deliver data.

-  @retval -1       Error condition occurred. Proper response is to reset the

-                   connection.

-

-**/

-INTN

-TcpDeliverData (

-  IN OUT TCP_CB *Tcb

-  )

-{

-  LIST_ENTRY      *Entry;

-  NET_BUF         *Nbuf;

-  TCP_SEQNO       Seq;

-  TCP_SEG         *Seg;

-  UINT32          Urgent;

-

-  ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));

-

-  //

-  // make sure there is some data queued,

-  // and TCP is in a proper state

-  //

-  if (IsListEmpty (&Tcb->RcvQue) || !TCP_CONNECTED (Tcb->State)) {

-

-    return 0;

-  }

-

-  //

-  // Deliver data to the socket layer

-  //

-  Entry = Tcb->RcvQue.ForwardLink;

-  Seq   = Tcb->RcvNxt;

-

-  while (Entry != &Tcb->RcvQue) {

-    Nbuf  = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);

-    Seg   = TCPSEG_NETBUF (Nbuf);

-

-    ASSERT (TcpVerifySegment (Nbuf) != 0);

-    ASSERT (Nbuf->Tcp == NULL);

-

-    if (TCP_SEQ_GT (Seg->Seq, Seq)) {

-      break;

-    }

-

-    Entry       = Entry->ForwardLink;

-    Seq         = Seg->End;

-    Tcb->RcvNxt = Seq;

-

-    RemoveEntryList (&Nbuf->List);

-

-    //

-    // RFC793 Eighth step: process FIN in sequence

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {

-

-      //

-      // The peer sends to us junky data after FIN,

-      // reset the connection.

-      //

-      if (!IsListEmpty (&Tcb->RcvQue)) {

-        DEBUG ((EFI_D_ERROR, "TcpDeliverData: data received after"

-          " FIN from peer of TCB %p, reset connection\n", Tcb));

-

-        NetbufFree (Nbuf);

-        return -1;

-      }

-

-      DEBUG ((EFI_D_NET, "TcpDeliverData: processing FIN "

-        "from peer of TCB %p\n", Tcb));

-

-      switch (Tcb->State) {

-      case TCP_SYN_RCVD:

-      case TCP_ESTABLISHED:

-

-        TcpSetState (Tcb, TCP_CLOSE_WAIT);

-        break;

-

-      case TCP_FIN_WAIT_1:

-

-        if (!TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {

-

-          TcpSetState (Tcb, TCP_CLOSING);

-          break;

-        }

-

-      //

-      // fall through

-      //

-      case TCP_FIN_WAIT_2:

-

-        TcpSetState (Tcb, TCP_TIME_WAIT);

-        TcpClearAllTimer (Tcb);

-

-        if (Tcb->TimeWaitTimeout != 0) {

-

-          TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);

-        } else {

-

-          DEBUG ((EFI_D_WARN, "Connection closed immediately "

-            "because app disables TIME_WAIT timer for %p\n", Tcb));

-

-          TcpSendAck (Tcb);

-          TcpClose (Tcb);

-        }

-        break;

-

-      case TCP_CLOSE_WAIT:

-      case TCP_CLOSING:

-      case TCP_LAST_ACK:

-      case TCP_TIME_WAIT:

-        //

-        // The peer sends to us junk FIN byte. Discard

-        // the buffer then reset the connection

-        //

-        NetbufFree (Nbuf);

-        return -1;

-      default:

-        break;

-      }

-

-      TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);

-

-      Seg->End--;

-    }

-

-    //

-    // Don't delay the ack if PUSH flag is on.

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_PSH)) {

-

-      TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);

-    }

-

-    if (Nbuf->TotalSize != 0) {

-      Urgent = 0;

-

-      if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) &&

-          TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvUp)) {

-

-        if (TCP_SEQ_LEQ (Seg->End, Tcb->RcvUp)) {

-          Urgent = Nbuf->TotalSize;

-        } else {

-          Urgent = TCP_SUB_SEQ (Tcb->RcvUp, Seg->Seq) + 1;

-        }

-      }

-

-      SockDataRcvd (Tcb->Sk, Nbuf, Urgent);

-    }

-

-    if (TCP_FIN_RCVD (Tcb->State)) {

-

-      SockNoMoreData (Tcb->Sk);

-    }

-

-    NetbufFree (Nbuf);

-  }

-

-  return 0;

-}

-

-

-/**

-  Store the data into the reassemble queue.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Nbuf     Pointer to the buffer containing the data to be queued.

-

-**/

-VOID

-TcpQueueData (

-  IN OUT TCP_CB  *Tcb,

-  IN     NET_BUF *Nbuf

-  )

-{

-  TCP_SEG         *Seg;

-  LIST_ENTRY      *Head;

-  LIST_ENTRY      *Prev;

-  LIST_ENTRY      *Cur;

-  NET_BUF         *Node;

-

-  ASSERT ((Tcb != NULL) && (Nbuf != NULL) && (Nbuf->Tcp == NULL));

-

-  NET_GET_REF (Nbuf);

-

-  Seg   = TCPSEG_NETBUF (Nbuf);

-  Head  = &Tcb->RcvQue;

-

-  //

-  // Fast path to process normal case. That is,

-  // no out-of-order segments are received.

-  //

-  if (IsListEmpty (Head)) {

-

-    InsertTailList (Head, &Nbuf->List);

-    return;

-  }

-

-  //

-  // Find the point to insert the buffer

-  //

-  for (Prev = Head, Cur = Head->ForwardLink;

-       Cur != Head;

-       Prev = Cur, Cur = Cur->ForwardLink) {

-

-    Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);

-

-    if (TCP_SEQ_LT (Seg->Seq, TCPSEG_NETBUF (Node)->Seq)) {

-      break;

-    }

-  }

-

-  //

-  // Check whether the current segment overlaps with the

-  // previous segment.

-  //

-  if (Prev != Head) {

-    Node = NET_LIST_USER_STRUCT (Prev, NET_BUF, List);

-

-    if (TCP_SEQ_LT (Seg->Seq, TCPSEG_NETBUF (Node)->End)) {

-

-      if (TCP_SEQ_LEQ (Seg->End, TCPSEG_NETBUF (Node)->End)) {

-

-        NetbufFree (Nbuf);

-        return;

-      }

-

-      TcpTrimSegment (Nbuf, TCPSEG_NETBUF (Node)->End, Seg->End);

-    }

-  }

-

-  InsertHeadList (Prev, &Nbuf->List);

-

-  TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);

-

-  //

-  // Check the segments after the insert point.

-  //

-  while (Cur != Head) {

-    Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);

-

-    if (TCP_SEQ_LEQ (TCPSEG_NETBUF (Node)->End, Seg->End)) {

-

-      Cur = Cur->ForwardLink;

-

-      RemoveEntryList (&Node->List);

-      NetbufFree (Node);

-      continue;

-    }

-

-    if (TCP_SEQ_LT (TCPSEG_NETBUF (Node)->Seq, Seg->End)) {

-

-      if (TCP_SEQ_LEQ (TCPSEG_NETBUF (Node)->Seq, Seg->Seq)) {

-

-        RemoveEntryList (&Nbuf->List);

-        NetbufFree (Nbuf);

-        return ;

-      }

-

-      TcpTrimSegment (Nbuf, Seg->Seq, TCPSEG_NETBUF (Node)->Seq);

-      break;

-    }

-

-    Cur = Cur->ForwardLink;

-  }

-}

-

-

-/**

-  Ajust the send queue or the retransmit queue.

-

-  @param  Tcb      Pointer to the TCP_CB of this TCP instance.

-  @param  Ack      The acknowledge seuqence number of the received segment.

-

-**/

-VOID

-TcpAdjustSndQue (

-  IN TCP_CB    *Tcb,

-  IN TCP_SEQNO Ack

-  )

-{

-  LIST_ENTRY      *Head;

-  LIST_ENTRY      *Cur;

-  NET_BUF         *Node;

-  TCP_SEG         *Seg;

-

-  Head  = &Tcb->SndQue;

-  Cur   = Head->ForwardLink;

-

-  while (Cur != Head) {

-    Node  = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);

-    Seg   = TCPSEG_NETBUF (Node);

-

-    if (TCP_SEQ_GEQ (Seg->Seq, Ack)) {

-      break;

-    }

-

-    //

-    // Remove completely ACKed segments

-    //

-    if (TCP_SEQ_LEQ (Seg->End, Ack)) {

-      Cur = Cur->ForwardLink;

-

-      RemoveEntryList (&Node->List);

-      NetbufFree (Node);

-      continue;

-    }

-

-    TcpTrimSegment (Node, Ack, Seg->End);

-    break;

-  }

-}

-

-

-/**

-  Process the received TCP segments.

-

-  @param  Nbuf     Buffer that contains received TCP segment without IP header.

-  @param  Src      Source address of the segment, or the peer's IP address.

-  @param  Dst      Destination address of the segment, or the local end's IP

-                   address.

-

-  @retval 0        Segment is processed successfully. It is either accepted or

-                   discarded. But no connection is reset by the segment.

-  @retval -1       A connection is reset by the segment.

-

-**/

-INTN

-TcpInput (

-  IN NET_BUF *Nbuf,

-  IN UINT32  Src,

-  IN UINT32  Dst

-  )

-{

-  TCP_CB      *Tcb;

-  TCP_CB      *Parent;

-  TCP_OPTION  Option;

-  TCP_HEAD    *Head;

-  INT32       Len;

-  TCP_SEG     *Seg;

-  TCP_SEQNO   Right;

-  TCP_SEQNO   Urg;

-

-  NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);

-

-  Parent  = NULL;

-  Tcb     = NULL;

-

-  Head    = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);

-  ASSERT (Head != NULL);

-

-  if (Nbuf->TotalSize < sizeof (TCP_HEAD)) {

-    DEBUG ((EFI_D_NET, "TcpInput: received a malformed packet\n"));

-    goto DISCARD;

-  }

-  

-  Len     = Nbuf->TotalSize - (Head->HeadLen << 2);

-

-  if ((Head->HeadLen < 5) || (Len < 0) ||

-      (TcpChecksum (Nbuf, NetPseudoHeadChecksum (Src, Dst, 6, 0)) != 0)) {

-

-    DEBUG ((EFI_D_NET, "TcpInput: received a malformed packet\n"));

-    goto DISCARD;

-  }

-

-  if (TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)) {

-    Len++;

-  }

-

-  if (TCP_FLG_ON (Head->Flag, TCP_FLG_FIN)) {

-    Len++;

-  }

-

-  Tcb = TcpLocateTcb (

-          Head->DstPort,

-          Dst,

-          Head->SrcPort,

-          Src,

-          (BOOLEAN) TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)

-          );

-

-  if ((Tcb == NULL) || (Tcb->State == TCP_CLOSED)) {

-    DEBUG ((EFI_D_NET, "TcpInput: send reset because no TCB found\n"));

-

-    Tcb = NULL;

-    goto SEND_RESET;

-  }

-

-  Seg = TcpFormatNetbuf (Tcb, Nbuf);

-

-  //

-  // RFC1122 recommended reaction to illegal option

-  // (in fact, an illegal option length) is reset.

-  //

-  if (TcpParseOption (Nbuf->Tcp, &Option) == -1) {

-    DEBUG ((EFI_D_ERROR, "TcpInput: reset the peer because"

-      " of malformed option for TCB %p\n", Tcb));

-

-    goto SEND_RESET;

-  }

-

-  //

-  // From now on, the segment is headless

-  //

-  NetbufTrim (Nbuf, (Head->HeadLen << 2), NET_BUF_HEAD);

-  Nbuf->Tcp = NULL;

-

-  //

-  // Process the segment in LISTEN state.

-  //

-  if (Tcb->State == TCP_LISTEN) {

-    //

-    // First step: Check RST

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {

-      DEBUG ((EFI_D_WARN, "TcpInput: discard a reset segment "

-        "for TCB %p in listening\n", Tcb));

-

-      goto DISCARD;

-    }

-

-    //

-    // Second step: Check ACK.

-    // Any ACK sent to TCP in LISTEN is reseted.

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {

-      DEBUG ((EFI_D_WARN, "TcpInput: send reset because of"

-        " segment with ACK for TCB %p in listening\n", Tcb));

-

-      goto SEND_RESET;

-    }

-

-    //

-    // Third step: Check SYN

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {

-      //

-      // create a child TCB to handle the data

-      //

-      Parent  = Tcb;

-

-      Tcb     = TcpCloneTcb (Parent);

-      if (Tcb == NULL) {

-        DEBUG ((EFI_D_ERROR, "TcpInput: discard a segment because"

-          " failed to clone a child for TCB %p\n", Tcb));

-

-        goto DISCARD;

-      }

-

-      DEBUG ((EFI_D_NET, "TcpInput: create a child for TCB %p"

-        " in listening\n", Tcb));

-

-      //

-      // init the TCB structure

-      //

-      Tcb->LocalEnd.Ip    = Dst;

-      Tcb->LocalEnd.Port  = Head->DstPort;

-      Tcb->RemoteEnd.Ip   = Src;

-      Tcb->RemoteEnd.Port = Head->SrcPort;

-

-      TcpInitTcbLocal (Tcb);

-      TcpInitTcbPeer (Tcb, Seg, &Option);

-

-      TcpSetState (Tcb, TCP_SYN_RCVD);

-      TcpSetTimer (Tcb, TCP_TIMER_CONNECT, Tcb->ConnectTimeout);

-      TcpTrimInWnd (Tcb, Nbuf);

-

-      goto StepSix;

-    }

-

-    goto DISCARD;

-

-  } else if (Tcb->State == TCP_SYN_SENT) {

-    //

-    // First step: Check ACK bit

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK) && (Seg->Ack != Tcb->Iss + 1)) {

-

-      DEBUG ((EFI_D_WARN, "TcpInput: send reset because of "

-        "wrong ACK received for TCB %p in SYN_SENT\n", Tcb));

-

-      goto SEND_RESET;

-    }

-

-    //

-    // Second step: Check RST bit

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {

-

-      if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {

-

-        DEBUG ((EFI_D_WARN, "TcpInput: connection reset by"

-          " peer for TCB %p in SYN_SENT\n", Tcb));

-

-        SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);

-        goto DROP_CONNECTION;

-      } else {

-

-        DEBUG ((EFI_D_WARN, "TcpInput: discard a reset segment "

-          "because of no ACK for TCB %p in SYN_SENT\n", Tcb));

-

-        goto DISCARD;

-      }

-    }

-

-    //

-    // Third step: Check security and precedence. Skipped

-    //

-

-    //

-    // Fourth step: Check SYN. Pay attention to simultaneous open

-    //

-    if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {

-

-      TcpInitTcbPeer (Tcb, Seg, &Option);

-

-      if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {

-

-        Tcb->SndUna = Seg->Ack;

-      }

-

-      TcpClearTimer (Tcb, TCP_TIMER_REXMIT);

-

-      if (TCP_SEQ_GT (Tcb->SndUna, Tcb->Iss)) {

-

-        TcpSetState (Tcb, TCP_ESTABLISHED);

-

-        TcpClearTimer (Tcb, TCP_TIMER_CONNECT);

-        TcpDeliverData (Tcb);

-

-        if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&

-            TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {

-

-          TcpComputeRtt (Tcb, Tcb->RttMeasure);

-          TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);

-        }

-

-        TcpTrimInWnd (Tcb, Nbuf);

-

-        TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);

-

-        DEBUG ((EFI_D_NET, "TcpInput: connection established"

-          " for TCB %p in SYN_SENT\n", Tcb));

-

-        goto StepSix;

-      } else {

-        //

-        // Received a SYN segment without ACK, simultaneous open.

-        //

-        TcpSetState (Tcb, TCP_SYN_RCVD);

-

-        ASSERT (Tcb->SndNxt == Tcb->Iss + 1);

-        TcpAdjustSndQue (Tcb, Tcb->SndNxt);

-

-        TcpTrimInWnd (Tcb, Nbuf);

-

-        DEBUG ((EFI_D_WARN, "TcpInput: simultaneous open "

-          "for TCB %p in SYN_SENT\n", Tcb));

-

-        goto StepSix;

-      }

-    }

-

-    goto DISCARD;

-  }

-

-  //

-  // Process segment in SYN_RCVD or TCP_CONNECTED states

-  //

-

-  //

-  // Clear probe timer since the RecvWindow is opened.

-  //

-  if (Tcb->ProbeTimerOn && (Seg->Wnd != 0)) {

-    TcpClearTimer (Tcb, TCP_TIMER_PROBE);

-    Tcb->ProbeTimerOn = FALSE;

-  }

-

-  //

-  // First step: Check whether SEG.SEQ is acceptable

-  //

-  if (TcpSeqAcceptable (Tcb, Seg) == 0) {

-    DEBUG ((EFI_D_WARN, "TcpInput: sequence acceptance"

-      " test failed for segment of TCB %p\n", Tcb));

-

-    if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {

-      TcpSendAck (Tcb);

-    }

-

-    goto DISCARD;

-  }

-

-  if ((TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2)) &&

-      (Tcb->RcvWl2 == Seg->End) &&

-      !TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN | TCP_FLG_FIN)) {

-

-    TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);

-  }

-

-  //

-  // Second step: Check the RST

-  //

-  if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {

-

-    DEBUG ((EFI_D_WARN, "TcpInput: connection reset for TCB %p\n", Tcb));

-

-    if (Tcb->State == TCP_SYN_RCVD) {

-

-      SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_REFUSED);

-

-      //

-      // This TCB comes from either a LISTEN TCB,

-      // or active open TCB with simultanous open.

-      // Do NOT signal user CONNECTION refused

-      // if it comes from a LISTEN TCB.

-      //

-    } else if ((Tcb->State == TCP_ESTABLISHED) ||

-               (Tcb->State == TCP_FIN_WAIT_1) ||

-               (Tcb->State == TCP_FIN_WAIT_2) ||

-               (Tcb->State == TCP_CLOSE_WAIT)) {

-

-      SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);

-

-    } else {

-

-    }

-

-    goto DROP_CONNECTION;

-  }

-

-  //

-  // Trim the data and flags.

-  //

-  TcpTrimInWnd (Tcb, Nbuf);

-

-  //

-  // Third step: Check security and precedence, Ignored

-  //

-

-  //

-  // Fourth step: Check the SYN bit.

-  //

-  if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {

-

-    DEBUG ((EFI_D_WARN, "TcpInput: connection reset "

-      "because received extra SYN for TCB %p\n", Tcb));

-

-    SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);

-    goto RESET_THEN_DROP;

-  }

-

-  //

-  // Fifth step: Check the ACK

-  //

-  if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {

-    DEBUG ((EFI_D_WARN, "TcpInput: segment discard because"

-      " of no ACK for connected TCB %p\n", Tcb));

-

-    goto DISCARD;

-

-  }

-

-  if (Tcb->State == TCP_SYN_RCVD) {

-

-    if (TCP_SEQ_LT (Tcb->SndUna, Seg->Ack) &&

-        TCP_SEQ_LEQ (Seg->Ack, Tcb->SndNxt)) {

-

-      Tcb->SndWnd     = Seg->Wnd;

-      Tcb->SndWndMax  = MAX (Tcb->SndWnd, Tcb->SndWndMax);

-      Tcb->SndWl1     = Seg->Seq;

-      Tcb->SndWl2     = Seg->Ack;

-      TcpSetState (Tcb, TCP_ESTABLISHED);

-

-      TcpClearTimer (Tcb, TCP_TIMER_CONNECT);

-      TcpDeliverData (Tcb);

-

-      DEBUG ((EFI_D_NET, "TcpInput: connection established "

-        " for TCB %p in SYN_RCVD\n", Tcb));

-

-      //

-      // Continue the process as ESTABLISHED state

-      //

-    } else {

-      DEBUG ((EFI_D_WARN, "TcpInput: send reset because of"

-        " wrong ACK for TCB %p in SYN_RCVD\n", Tcb));

-

-      goto SEND_RESET;

-    }

-  }

-

-  if (TCP_SEQ_LT (Seg->Ack, Tcb->SndUna)) {

-

-    DEBUG ((EFI_D_WARN, "TcpInput: ignore the out-of-data"

-      " ACK for connected TCB %p\n", Tcb));

-

-    goto StepSix;

-

-  } else if (TCP_SEQ_GT (Seg->Ack, Tcb->SndNxt)) {

-

-    DEBUG ((EFI_D_WARN, "TcpInput: discard segment for "

-      "future ACK for connected TCB %p\n", Tcb));

-

-    TcpSendAck (Tcb);

-    goto DISCARD;

-  }

-

-  //

-  // From now on: SND.UNA <= SEG.ACK <= SND.NXT.

-  //

-  if (TCP_FLG_ON (Option.Flag, TCP_OPTION_RCVD_TS)) {

-    //

-    // update TsRecent as specified in page 16 RFC1323.

-    // RcvWl2 equals to the variable "LastAckSent"

-    // defined there.

-    //

-    if (TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvWl2) &&

-        TCP_SEQ_LT (Tcb->RcvWl2, Seg->End)) {

-

-      Tcb->TsRecent     = Option.TSVal;

-      Tcb->TsRecentAge  = mTcpTick;

-    }

-

-    TcpComputeRtt (Tcb, TCP_SUB_TIME (mTcpTick, Option.TSEcr));

-

-  } else if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {

-

-    ASSERT (Tcb->CongestState == TCP_CONGEST_OPEN);

-

-    TcpComputeRtt (Tcb, Tcb->RttMeasure);

-    TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);

-  }

-

-  if (Seg->Ack == Tcb->SndNxt) {

-

-    TcpClearTimer (Tcb, TCP_TIMER_REXMIT);

-  } else {

-

-    TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);

-  }

-

-  //

-  // Count duplicate acks.

-  //

-  if ((Seg->Ack == Tcb->SndUna) &&

-      (Tcb->SndUna != Tcb->SndNxt) &&

-      (Seg->Wnd == Tcb->SndWnd) &&

-      (0 == Len)) {

-

-    Tcb->DupAck++;

-  } else {

-

-    Tcb->DupAck = 0;

-  }

-

-  //

-  // Congestion avoidance, fast recovery and fast retransmission.

-  //

-  if (((Tcb->CongestState == TCP_CONGEST_OPEN) && (Tcb->DupAck < 3)) ||

-      (Tcb->CongestState == TCP_CONGEST_LOSS)) {

-

-    if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {

-

-      if (Tcb->CWnd < Tcb->Ssthresh) {

-

-        Tcb->CWnd += Tcb->SndMss;

-      } else {

-

-        Tcb->CWnd += MAX (Tcb->SndMss * Tcb->SndMss / Tcb->CWnd, 1);

-      }

-

-      Tcb->CWnd = MIN (Tcb->CWnd, TCP_MAX_WIN << Tcb->SndWndScale);

-    }

-

-    if (Tcb->CongestState == TCP_CONGEST_LOSS) {

-      TcpFastLossRecover (Tcb, Seg);

-    }

-  } else {

-

-    TcpFastRecover (Tcb, Seg);

-  }

-

-  if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {

-

-    TcpAdjustSndQue (Tcb, Seg->Ack);

-    Tcb->SndUna = Seg->Ack;

-

-    if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&

-        TCP_SEQ_LT (Tcb->SndUp, Seg->Ack)) {

-

-      TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_URG);

-    }

-  }

-

-  //

-  // Update window info

-  //

-  if (TCP_SEQ_LT (Tcb->SndWl1, Seg->Seq) ||

-      ((Tcb->SndWl1 == Seg->Seq) && TCP_SEQ_LEQ (Tcb->SndWl2, Seg->Ack))) {

-

-    Right = Seg->Ack + Seg->Wnd;

-

-    if (TCP_SEQ_LT (Right, Tcb->SndWl2 + Tcb->SndWnd)) {

-

-      if ((Tcb->SndWl1 == Seg->Seq) &&

-          (Tcb->SndWl2 == Seg->Ack) &&

-          (Len == 0)) {

-

-        goto NO_UPDATE;

-      }

-

-      DEBUG ((EFI_D_WARN, "TcpInput: peer shrinks the"

-        " window for connected TCB %p\n", Tcb));

-

-      if ((Tcb->CongestState == TCP_CONGEST_RECOVER) &&

-          (TCP_SEQ_LT (Right, Tcb->Recover))) {

-

-        Tcb->Recover = Right;

-      }

-

-      if ((Tcb->CongestState == TCP_CONGEST_LOSS) &&

-          (TCP_SEQ_LT (Right, Tcb->LossRecover))) {

-

-        Tcb->LossRecover = Right;

-      }

-

-      if (TCP_SEQ_LT (Right, Tcb->SndNxt)) {

-

-        Tcb->SndNxt = Right;

-

-        if (Right == Tcb->SndUna) {

-

-          TcpClearTimer (Tcb, TCP_TIMER_REXMIT);

-          TcpSetProbeTimer (Tcb);

-        }

-      }

-    }

-

-    Tcb->SndWnd     = Seg->Wnd;

-    Tcb->SndWndMax  = MAX (Tcb->SndWnd, Tcb->SndWndMax);

-    Tcb->SndWl1     = Seg->Seq;

-    Tcb->SndWl2     = Seg->Ack;

-  }

-

-NO_UPDATE:

-

-  if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT) &&

-      (Tcb->SndUna == Tcb->SndNxt)) {

-

-    DEBUG ((EFI_D_NET, "TcpInput: local FIN is ACKed by"

-      " peer for connected TCB %p\n", Tcb));

-

-    TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED);

-  }

-

-  //

-  // Transit the state if proper.

-  //

-  switch (Tcb->State) {

-  case TCP_FIN_WAIT_1:

-

-    if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {

-

-      TcpSetState (Tcb, TCP_FIN_WAIT_2);

-

-      TcpClearAllTimer (Tcb);

-      TcpSetTimer (Tcb, TCP_TIMER_FINWAIT2, Tcb->FinWait2Timeout);

-    }

-

-  case TCP_FIN_WAIT_2:

-

-    break;

-

-  case TCP_CLOSE_WAIT:

-    break;

-

-  case TCP_CLOSING:

-

-    if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {

-

-      TcpSetState (Tcb, TCP_TIME_WAIT);

-

-      TcpClearAllTimer (Tcb);

-

-      if (Tcb->TimeWaitTimeout != 0) {

-

-        TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);

-      } else {

-

-        DEBUG ((EFI_D_WARN, "Connection closed immediately "

-          "because app disables TIME_WAIT timer for %p\n", Tcb));

-

-        TcpClose (Tcb);

-      }

-    }

-    break;

-

-  case TCP_LAST_ACK:

-

-    if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {

-

-      TcpSetState (Tcb, TCP_CLOSED);

-    }

-

-    break;

-

-  case TCP_TIME_WAIT:

-

-    TcpSendAck (Tcb);

-

-    if (Tcb->TimeWaitTimeout != 0) {

-

-      TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);

-    } else {

-

-      DEBUG ((EFI_D_WARN, "Connection closed immediately "

-        "because app disables TIME_WAIT timer for %p\n", Tcb));

-

-      TcpClose (Tcb);

-    }

-    break;

-

-  default:

-    break;

-  }

-

-  //

-  // Sixth step: Check the URG bit.update the Urg point

-  // if in TCP_CAN_RECV, otherwise, leave the RcvUp intact.

-  //

-StepSix:

-

-  Tcb->Idle = 0;

-  TcpSetKeepaliveTimer (Tcb);

-

-  if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG) &&

-      !TCP_FIN_RCVD (Tcb->State)) 

-  {

-

-    DEBUG ((EFI_D_NET, "TcpInput: received urgent data "

-      "from peer for connected TCB %p\n", Tcb));

-

-    Urg = Seg->Seq + Seg->Urg;

-

-    if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) &&

-        TCP_SEQ_GT (Urg, Tcb->RcvUp)) {

-

-      Tcb->RcvUp = Urg;

-    } else {

-

-      Tcb->RcvUp = Urg;

-      TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG);

-    }

-  }

-

-  //

-  // Seventh step: Process the segment data

-  //

-  if (Seg->End != Seg->Seq) {

-

-    if (TCP_FIN_RCVD (Tcb->State)) {

-

-      DEBUG ((EFI_D_WARN, "TcpInput: connection reset because"

-        " data is lost for connected TCB %p\n", Tcb));

-

-      goto RESET_THEN_DROP;

-    }

-

-    if (TCP_LOCAL_CLOSED (Tcb->State) && (Nbuf->TotalSize != 0)) {

-      DEBUG ((EFI_D_WARN, "TcpInput: connection reset because"

-        " data is lost for connected TCB %p\n", Tcb));

-

-      goto RESET_THEN_DROP;

-    }

-

-    TcpQueueData (Tcb, Nbuf);

-    if (TcpDeliverData (Tcb) == -1) {

-      goto RESET_THEN_DROP;

-    }

-

-    if (!IsListEmpty (&Tcb->RcvQue)) {

-      TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);

-    }

-  }

-

-  //

-  // Eighth step: check the FIN.

-  // This step is moved to TcpDeliverData. FIN will be

-  // processed in sequence there. Check the comments in

-  // the beginning of the file header for information.

-  //

-

-  //

-  // Tcb is a new child of the listening Parent,

-  // commit it.

-  //

-  if (Parent != NULL) {

-    Tcb->Parent = Parent;

-    TcpInsertTcb (Tcb);

-  }

-

-  if ((Tcb->State != TCP_CLOSED) &&

-      (TcpToSendData (Tcb, 0) == 0) &&

-      (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) || (Nbuf->TotalSize != 0))) {

-

-    TcpToSendAck (Tcb);

-  }

-

-  NetbufFree (Nbuf);

-  return 0;

-

-RESET_THEN_DROP:

-  TcpSendReset (Tcb, Head, Len, Dst, Src);

-

-DROP_CONNECTION:

-  ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));

-

-  NetbufFree (Nbuf);

-  TcpClose (Tcb);

-

-  return -1;

-

-SEND_RESET:

-

-  TcpSendReset (Tcb, Head, Len, Dst, Src);

-

-DISCARD:

-

-  //

-  // Tcb is a child of Parent, and it doesn't survive

-  //

-  DEBUG ((EFI_D_WARN, "Tcp4Input: Discard a packet\n"));

-  NetbufFree (Nbuf);

-

-  if ((Parent != NULL) && (Tcb != NULL)) {

-

-    ASSERT (Tcb->Sk != NULL);

-    TcpClose (Tcb);

-  }

-

-  return 0;

-}

-

-

-/**

-  Process the received ICMP error messages for TCP.

-

-  @param  Nbuf     Buffer that contains part of the TCP segment without IP header

-                   truncated from the ICMP error packet.

-  @param  IcmpErr  The ICMP error code interpreted from ICMP error packet.

-  @param  Src      Source address of the ICMP error message.

-  @param  Dst      Destination address of the ICMP error message.

-

-**/

-VOID

-TcpIcmpInput (

-  IN NET_BUF     *Nbuf,

-  IN UINT8       IcmpErr,

-  IN UINT32      Src,

-  IN UINT32      Dst

-  )

-{

-  TCP_HEAD         *Head;

-  TCP_CB           *Tcb;

-  TCP_SEQNO        Seq;

-  EFI_STATUS       IcmpErrStatus;

-  BOOLEAN          IcmpErrIsHard;

-  BOOLEAN          IcmpErrNotify;

-

-  if (Nbuf->TotalSize < sizeof (TCP_HEAD)) {

-    goto CLEAN_EXIT;

-  }

-

-  Head = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);

-  ASSERT (Head != NULL);

-  Tcb = TcpLocateTcb (

-          Head->DstPort,

-          Dst,

-          Head->SrcPort,

-          Src,

-          FALSE

-          );

-  if (Tcb == NULL || Tcb->State == TCP_CLOSED) {

-

-    goto CLEAN_EXIT;

-  }

-

-  //

-  // Validate the sequence number.

-  //

-  Seq = NTOHL (Head->Seq);

-  if (!(TCP_SEQ_LEQ (Tcb->SndUna, Seq) && TCP_SEQ_LT (Seq, Tcb->SndNxt))) {

-

-    goto CLEAN_EXIT;

-  }

-

-  IcmpErrStatus = IpIoGetIcmpErrStatus (

-                    IcmpErr,

-                    IP_VERSION_4,

-                    &IcmpErrIsHard,

-                    &IcmpErrNotify

-                    );

-

-  if (IcmpErrNotify) {

-

-    SOCK_ERROR (Tcb->Sk, IcmpErrStatus);

-  }

-

-  if (IcmpErrIsHard) {

-

-    TcpClose (Tcb);

-  }

-

-CLEAN_EXIT:

-  NetbufFree (Nbuf);

-}