[PATCH] NetworkPkg: Fix RSOD issue in Ip6Dxe

[Gary Li <garyli@hpe.com>]

Avoid the Ip6NdFasterTimerTicking is executed again before the previous Ip6NdFasterTimerTicking is done.
When user presses hotkey between the below line, it makes the Ip6NdFasterTimerTicking is dispatched again before the previous Ip6NdFasterTimerTicking is done.
Therefore, the DelayNode node will be removed twice.

DelayNode = NET_LIST_USER_STRUCT (Entry2, IP6_DELAY_JOIN_LIST, Link);
...
RemoveEntryList (&DelayNode->Link);

Contributed-under: TianoCore Contribution Agreement 1.0

Signed-off-by: Gary Li <garyli@hpe.com>
---
 NetworkPkg/Ip6Dxe/Ip6Nd.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/NetworkPkg/Ip6Dxe/Ip6Nd.c b/NetworkPkg/Ip6Dxe/Ip6Nd.c
index a3f49bb..d400d7c 100644
--- a/NetworkPkg/Ip6Dxe/Ip6Nd.c
+++ b/NetworkPkg/Ip6Dxe/Ip6Nd.c
@@ -2,6 +2,7 @@
   Implementation of Neighbor Discovery support routines.
 
   Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
+  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -16,6 +17,7 @@
 #include "Ip6Impl.h"
 
 EFI_MAC_ADDRESS mZeroMacAddress;
+BOOLEAN mIsInIp6NdFasterTimerTicking = FALSE;
 
 /**
   Update the ReachableTime in IP6 service binding instance data, in milliseconds.
@@ -2774,6 +2776,12 @@ Ip6NdFasterTimerTicking (
   IP6_SERVICE               *IpSb;
   BOOLEAN                   Flag;
 
+  if (!mIsInIp6NdFasterTimerTicking) {
+    mIsInIp6NdFasterTimerTicking = TRUE;
+  } else {
+    return;
+  }
+
   IpSb = (IP6_SERVICE *) Context;
   NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);
 
@@ -2848,7 +2856,7 @@ Ip6NdFasterTimerTicking (
                      NULL
                      );
           if (EFI_ERROR (Status)) {
-            return;
+            goto Exit;
           }
 
           DupAddrDetect->Transmit++;
@@ -2896,7 +2904,7 @@ Ip6NdFasterTimerTicking (
           Ip6CreateSNMulticastAddr (&NeighborCache->Neighbor, &Destination);
           Status = Ip6SelectSourceAddress (IpSb, &NeighborCache->Neighbor, &Source);
           if (EFI_ERROR (Status)) {
-            return;
+            goto Exit;
           }
 
           Status = Ip6SendNeighborSolicit (
@@ -2907,7 +2915,7 @@ Ip6NdFasterTimerTicking (
                      &IpSb->SnpMode.CurrentAddress
                      );
           if (EFI_ERROR (Status)) {
-            return;
+            goto Exit;
           }
         }
 
@@ -2934,7 +2942,7 @@ Ip6NdFasterTimerTicking (
                    NULL
                    );
         if (EFI_ERROR (Status)) {
-          return;
+          goto Exit;
         }
       }
 
@@ -2965,7 +2973,7 @@ Ip6NdFasterTimerTicking (
                      NULL
                      );
           if (EFI_ERROR (Status)) {
-            return;
+            goto Exit;
           }
         } else {
           NeighborCache->State = EfiNeighborStale;
@@ -2986,7 +2994,7 @@ Ip6NdFasterTimerTicking (
         //
         Status = Ip6SelectSourceAddress (IpSb, &NeighborCache->Neighbor, &Source);
         if (EFI_ERROR (Status)) {
-          return;
+          goto Exit;
         }
 
         Status = Ip6SendNeighborSolicit (
@@ -2997,7 +3005,7 @@ Ip6NdFasterTimerTicking (
                    &IpSb->SnpMode.CurrentAddress
                    );
         if (EFI_ERROR (Status)) {
-          return;
+          goto Exit;
         }
 
         NeighborCache->Transmit--;
@@ -3023,7 +3031,7 @@ Ip6NdFasterTimerTicking (
           //
           Status = Ip6SelectSourceAddress (IpSb, &NeighborCache->Neighbor, &Source);
           if (EFI_ERROR (Status)) {
-            return;
+            goto Exit;
           }
 
           Status = Ip6SendNeighborSolicit (
@@ -3034,7 +3042,7 @@ Ip6NdFasterTimerTicking (
                      &IpSb->SnpMode.CurrentAddress
                      );
           if (EFI_ERROR (Status)) {
-            return;
+            goto Exit;
           }
         }
 
@@ -3061,7 +3069,7 @@ Ip6NdFasterTimerTicking (
                    NULL
                    );
         if (EFI_ERROR (Status)) {
-          return;
+          goto Exit;
         }
       }
 
@@ -3071,6 +3079,9 @@ Ip6NdFasterTimerTicking (
       break;
     }
   }
+
+Exit:
+  mIsInIp6NdFasterTimerTicking = FALSE;
 }
 
 /**
-- 
2.7.2.windows.1