From 0bb073b9e2cc58149b41a709c1f78db6c0f9a963 Mon Sep 17 00:00:00 2001
From: Zhang Lubo <lubo.zhang@intel.com>
Date: Wed, 24 Feb 2016 11:54:53 +0800
Subject: MdeModulePkg:Fix a robustness issue of Mnp Driver

v3:
*
When there exists duplicate items in VLAN variable , save the correct
variable content back to the variable storage after duplicate items are removed

Duplicate items in VLAN variable will cause MNP driver binding
start function fall into infinite loop,so we should check it's
content before using it.

Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Ye Ting <ting.ye@intel.com>
Cc: Wu Jiaxin <jiaxin.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Zhang Lubo <lubo.zhang@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Wu Jiaxin <jiaxin.wu@intel.com>
---
 MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c | 64 +++++++++++++++++++++++--
 1 file changed, 60 insertions(+), 4 deletions(-)

(limited to 'MdeModulePkg')

diff --git a/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c b/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
index 6e14c1f..98cbc2e 100644
--- a/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
+++ b/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
@@ -1,7 +1,7 @@
 /** @file
   VLAN Config Protocol implementation and VLAN packet process routine.
 
-Copyright (c) 2009 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 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
@@ -230,6 +230,59 @@ MnpInsertVlanTag (
   VlanTci->Uint16        = HTONS (VlanTci->Uint16);
 }
 
+/**
+  Check VLAN configuration variable and delete the duplicative content if has identical Vlan ID.
+
+  @param[in]      MnpDeviceData      Pointer to the MNP device context data.
+  @param[in]      Buffer             Pointer to the buffer contains the array of VLAN_TCI.
+  @param[in]      NumberOfVlan       Pointer to number of VLAN.
+  @param[out]     NewNumberOfVlan    Pointer to number of unique VLAN.
+  
+  @retval EFI_SUCCESS            The VLAN variable is successfully checked.
+  @retval EFI_OUT_OF_RESOURCES   There is not enough resource to set the configuration.
+
+**/
+EFI_STATUS
+MnpCheckVlanVariable (
+  IN     MNP_DEVICE_DATA   *MnpDeviceData,
+  IN     VLAN_TCI          *Buffer,
+  IN     UINTN             NumberOfVlan,
+     OUT UINTN             *NewNumberOfVlan
+  )
+{
+  UINTN             Index;
+  UINTN             Index2;
+  UINTN             Count;
+  BOOLEAN           FoundDuplicateItem;
+  EFI_STATUS        Status;
+
+  Count = 0;
+  FoundDuplicateItem  = FALSE;
+  Status = EFI_SUCCESS;
+  
+  for (Index = 0; Index < NumberOfVlan; Index++) {
+   for (Index2 = Index + 1; Index2 < NumberOfVlan; Index2++) {
+     if (Buffer[Index].Bits.Vid == Buffer[Index2].Bits.Vid) {
+       FoundDuplicateItem = TRUE;
+       Count++;
+       break;
+     }
+   }
+   if (FoundDuplicateItem) {
+    for (Index2 = Index +1; Index2 < NumberOfVlan; Index++, Index2++) {
+      CopyMem (Buffer + Index, Buffer + Index2, sizeof (VLAN_TCI));
+    }
+   }
+   FoundDuplicateItem = FALSE;
+  }
+
+  *NewNumberOfVlan = NumberOfVlan - Count;
+  if (Count != 0) {
+    Status = MnpSetVlanVariable (MnpDeviceData, *NewNumberOfVlan, Buffer);
+  }
+  
+  return Status;
+}
 
 /**
   Get VLAN configuration variable.
@@ -255,6 +308,7 @@ MnpGetVlanVariable (
   UINTN       BufferSize;
   EFI_STATUS  Status;
   VLAN_TCI    *Buffer;
+  UINTN       NewNumberOfVlan;
 
   //
   // Get VLAN configuration from EFI Variable
@@ -292,13 +346,15 @@ MnpGetVlanVariable (
     return Status;
   }
 
-  *NumberOfVlan = BufferSize / sizeof (VLAN_TCI);
-  *VlanVariable = Buffer;
+  Status = MnpCheckVlanVariable (MnpDeviceData, Buffer, BufferSize / sizeof (VLAN_TCI), &NewNumberOfVlan);
+  if (!EFI_ERROR (Status)) {
+    *NumberOfVlan = NewNumberOfVlan;
+    *VlanVariable = Buffer;
+  }
 
   return Status;
 }
 
-
 /**
   Set VLAN configuration variable.
 
-- 
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