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.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Wu Jiaxin <jiaxin.wu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>

diff --git a/NetworkPkg/TcpDxe/TcpMisc.c b/NetworkPkg/TcpDxe/TcpMisc.c
index a8592c968956a26fd1037751e943de47954aa751..44350362855f761a86b60e79b0940686255e338a 100644 (file)
--- a/NetworkPkg/TcpDxe/TcpMisc.c
+++ b/NetworkPkg/TcpDxe/TcpMisc.c
@@ -2,7 +2,7 @@
   Misc support routines for TCP driver.\r
 \r
   (C) Copyright 2014 Hewlett-Packard Development Company, L.P.<BR>\r
-  Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>\r
 \r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -86,6 +86,7 @@ TcpInitTcbLocal (
   // First window size is never scaled\r
   //\r
   Tcb->RcvWndScale  = 0;\r
+  Tcb->RetxmitSeqMax = 0;\r
 \r
   Tcb->ProbeTimerOn = FALSE;\r
 }\r

diff --git a/NetworkPkg/TcpDxe/TcpOutput.c b/NetworkPkg/TcpDxe/TcpOutput.c
index a46cb6099ea8ab72050c9d9bca35f9fa0763d172..a7e59f0ed6e0e60aa97aa2e755f0be4222eccd38 100644 (file)
--- a/NetworkPkg/TcpDxe/TcpOutput.c
+++ b/NetworkPkg/TcpDxe/TcpOutput.c
@@ -1,7 +1,7 @@
 /** @file\r
   TCP output process routines.\r
 \r
-  Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>\r
 \r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -664,7 +664,27 @@ TcpRetransmit (
   // 2. Must in the current send window\r
   // 3. Will not change the boundaries of queued segments.\r
   //\r
-  if (TCP_SEQ_LT (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {\r
+\r
+  //\r
+  // Handle the Window Retraction if TCP window scale is enabled according to RFC7323:\r
+  //   On first retransmission, or if the sequence number is out of\r
+  //   window by less than 2^Rcv.Wind.Shift, then do normal\r
+  //   retransmission(s) without regard to the receiver window as long\r
+  //   as the original segment was in window when it was sent.\r
+  //\r
+  if ((Tcb->SndWndScale != 0) &&\r
+      (TCP_SEQ_GT (Seq, Tcb->RetxmitSeqMax) || TCP_SEQ_BETWEEN (Tcb->SndWl2 + Tcb->SndWnd, Seq, Tcb->SndWl2 + Tcb->SndWnd + (1 << Tcb->SndWndScale)))) {\r
+    Len = TCP_SUB_SEQ (Tcb->SndNxt, Seq);\r
+    DEBUG (\r
+      (EFI_D_WARN,\r
+      "TcpRetransmit: retransmission without regard to the receiver window for TCB %p\n",\r
+      Tcb)\r
+      );\r
+    \r
+  } else if (TCP_SEQ_GEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {\r
+    Len = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);\r
+    \r
+  } else {\r
     DEBUG (\r
       (EFI_D_WARN,\r
       "TcpRetransmit: retransmission cancelled because send window too small for TCB %p\n",\r
@@ -674,10 +694,9 @@ TcpRetransmit (
     return 0;\r
   }\r
 \r
-  Len   = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);\r
-  Len   = MIN (Len, Tcb->SndMss);\r
+  Len = MIN (Len, Tcb->SndMss);\r
 \r
-  Nbuf  = TcpGetSegmentSndQue (Tcb, Seq, Len);\r
+  Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r
   if (Nbuf == NULL) {\r
     return -1;\r
   }\r
@@ -688,6 +707,10 @@ TcpRetransmit (
     goto OnError;\r
   }\r
 \r
+  if (TCP_SEQ_GT (Seq, Tcb->RetxmitSeqMax)) {\r
+    Tcb->RetxmitSeqMax = Seq;\r
+  }\r
+\r
   //\r
   // The retransmitted buffer may be on the SndQue,\r
   // trim TCP head because all the buffers on SndQue\r

diff --git a/NetworkPkg/TcpDxe/TcpProto.h b/NetworkPkg/TcpDxe/TcpProto.h
index ee351348339e0b7919bbe1fa89693c28cee8d884..81397d704d13eaafb99641a95e6908ef9c271062 100644 (file)
--- a/NetworkPkg/TcpDxe/TcpProto.h
+++ b/NetworkPkg/TcpDxe/TcpProto.h
@@ -1,7 +1,7 @@
 /** @file\r
   TCP protocol header file.\r
 \r
-  Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>\r
 \r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -315,6 +315,12 @@ struct _TCP_CONTROL_BLOCK {
   UINT8             LossTimes;    ///< Number of retxmit timeouts in a row.\r
   TCP_SEQNO         LossRecover;  ///< Recover point for retxmit.\r
 \r
+  //\r
+  // RFC7323\r
+  // Addressing Window Retraction for TCP Window Scale Option.\r
+  //\r
+  TCP_SEQNO         RetxmitSeqMax;       ///< Max Seq number in previous retransmission.\r
+\r
   //\r
   // configuration parameters, for EFI_TCP4_PROTOCOL specification\r
   //\r