Re: [Patch V2] NetworkPkg: Addressing TCP Window Retraction when window scale factor is used.

["Wu, Jiaxin" <jiaxin.wu@intel.com>]

Reviewed-by: Wu Jiaxin <jiaxin.wu@intel.com>



> -----Original Message-----
> From: Fu, Siyuan
> Sent: Friday, May 5, 2017 9:56 AM
> To: edk2-devel@lists.01.org
> Cc: Wu, Jiaxin <jiaxin.wu@intel.com>; Andrey Tepin <atepin@kraftway.ru>; Ye,
> Ting <ting.ye@intel.com>
> Subject: [Patch V2] NetworkPkg: Addressing TCP Window Retraction when
> window scale factor is used.
> 
> The RFC1323 which defines the TCP window scale option has been obsoleted by
> RFC7323.
> This patch is to follow the RFC7323 to address the TCP window retraction
> problem
> when a non-zero scale factor is used.
> The changes has been test in high packet loss rate network by using HTTP boot
> and
> iSCSI file read/write.
> 
> Cc: Wu Jiaxin <jiaxin.wu@intel.com>
> Cc: Andrey Tepin <atepin@kraftway.ru>
> Cc: Ye Ting <ting.ye@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
> ---
>  NetworkPkg/TcpDxe/TcpMisc.c   |  3 ++-
>  NetworkPkg/TcpDxe/TcpOutput.c | 33 ++++++++++++++++++++++++++++-----
>  NetworkPkg/TcpDxe/TcpProto.h  |  8 +++++++-
>  3 files changed, 37 insertions(+), 7 deletions(-)
> 
> diff --git a/NetworkPkg/TcpDxe/TcpMisc.c b/NetworkPkg/TcpDxe/TcpMisc.c
> index a8592c9..4435036 100644
> --- a/NetworkPkg/TcpDxe/TcpMisc.c
> +++ b/NetworkPkg/TcpDxe/TcpMisc.c
> @@ -2,7 +2,7 @@
>    Misc support routines for TCP driver.
> 
>    (C) Copyright 2014 Hewlett-Packard Development Company, L.P.<BR>
> -  Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2009 - 2017, 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
> @@ -86,6 +86,7 @@ TcpInitTcbLocal (
>    // First window size is never scaled
>    //
>    Tcb->RcvWndScale  = 0;
> +  Tcb->RetxmitSeqMax = 0;
> 
>    Tcb->ProbeTimerOn = FALSE;
>  }
> diff --git a/NetworkPkg/TcpDxe/TcpOutput.c
> b/NetworkPkg/TcpDxe/TcpOutput.c
> index a46cb60..f3dacf3 100644
> --- a/NetworkPkg/TcpDxe/TcpOutput.c
> +++ b/NetworkPkg/TcpDxe/TcpOutput.c
> @@ -1,7 +1,7 @@
>  /** @file
>    TCP output process routines.
> 
> -  Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2009 - 2017, 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
> @@ -664,7 +664,27 @@ TcpRetransmit (
>    // 2. Must in the current send window
>    // 3. Will not change the boundaries of queued segments.
>    //
> -  if (TCP_SEQ_LT (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {
> +
> +  if ((Tcb->SndWndScale != 0) &&
> +      (TCP_SEQ_GT (Seq, Tcb->RetxmitSeqMax) || TCP_SEQ_GT (Tcb->SndWl2 +
> Tcb->SndWnd + (1 << Tcb->SndWndScale), Seq))) {
> +    //
> +    // Handle the Window Retraction if TCP window scale is enabled according
> to RFC7323:
> +    //   On first retransmission, or if the sequence number is out of
> +    //   window by less than 2^Rcv.Wind.Shift, then do normal
> +    //   retransmission(s) without regard to the receiver window as long
> +    //   as the original segment was in window when it was sent.
> +    //
> +    Len = TCP_SUB_SEQ (Tcb->SndNxt, Seq);
> +    DEBUG (
> +      (EFI_D_WARN,
> +      "TcpRetransmit: retransmission without regard to the receiver window for
> TCB %p\n",
> +      Tcb)
> +      );
> +
> +  } else if (TCP_SEQ_GEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {
> +    Len = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);
> +
> +  } else {
>      DEBUG (
>        (EFI_D_WARN,
>        "TcpRetransmit: retransmission cancelled because send window too small
> for TCB %p\n",
> @@ -674,10 +694,9 @@ TcpRetransmit (
>      return 0;
>    }
> 
> -  Len   = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);
> -  Len   = MIN (Len, Tcb->SndMss);
> +  Len = MIN (Len, Tcb->SndMss);
> 
> -  Nbuf  = TcpGetSegmentSndQue (Tcb, Seq, Len);
> +  Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);
>    if (Nbuf == NULL) {
>      return -1;
>    }
> @@ -688,6 +707,10 @@ TcpRetransmit (
>      goto OnError;
>    }
> 
> +  if (TCP_SEQ_GT (Seq, Tcb->RetxmitSeqMax)) {
> +    Tcb->RetxmitSeqMax = Seq;
> +  }
> +
>    //
>    // The retransmitted buffer may be on the SndQue,
>    // trim TCP head because all the buffers on SndQue
> diff --git a/NetworkPkg/TcpDxe/TcpProto.h b/NetworkPkg/TcpDxe/TcpProto.h
> index ee35134..81397d7 100644
> --- a/NetworkPkg/TcpDxe/TcpProto.h
> +++ b/NetworkPkg/TcpDxe/TcpProto.h
> @@ -1,7 +1,7 @@
>  /** @file
>    TCP protocol header file.
> 
> -  Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2009 - 2017, 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
> @@ -316,6 +316,12 @@ struct _TCP_CONTROL_BLOCK {
>    TCP_SEQNO         LossRecover;  ///< Recover point for retxmit.
> 
>    //
> +  // RFC7323
> +  // Addressing Window Retraction for TCP Window Scale Option.
> +  //
> +  TCP_SEQNO         RetxmitSeqMax;       ///< Max Seq number in previous
> retransmission.
> +
> +  //
>    // configuration parameters, for EFI_TCP4_PROTOCOL specification
>    //
>    UINT32            KeepAliveIdle;   ///< Idle time before sending first probe.
> --
> 1.9.5.msysgit.1