Yes , it needs to be modified, thank you for the comment.
-----Original Message-----
From: Fu, Siyuan
Sent: Thursday, February 25, 2016 11:39 AM
To: Zhang, Lubo; edk2-devel@lists.01.org
Cc: Ye, Ting; Wu, Jiaxin
Subject: RE: [edk2] [PATCH v2] MdeModulePkg:Fix a robustness issue of Mnp Driver
Hi, Lubo
The "continue" should be "break" in below code, otherwise the Count is not
correct if there are more than 2 duplicate items in the variable. And please
save the correct variable content back to the variable storage after duplicate
items are removed.
> + if (Buffer[Index].Bits.Vid == Buffer[Index2].Bits.Vid) {
> + FoundDuplicateItem = TRUE;
> + Count++;
> + continue;
> + }
Siyuan
> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of
> Zhang Lubo
> Sent: Thursday, February 25, 2016 11:18 AM
> To: edk2-devel@lists.01.org
> Cc: Ye, Ting <ting...@intel.com>; Fu, Siyuan <siyuan...@intel.com>;
> Wu, Jiaxin <jiaxin...@intel.com>
> Subject: [edk2] [PATCH v2] MdeModulePkg:Fix a robustness issue of Mnp
> Driver
>
> v2:
> *
> If the VLAN has duplicate items, try to delete it instead using VLAN
> Id 4095 which is a "reserved" tag number.
>
> 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...@intel.com>
> Cc: Ye Ting <ting...@intel.com>
> Cc: Wu Jiaxin <jiaxin...@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Zhang Lubo <lubo.zh...@intel.com>
> ---
> MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c | 46
> +++++++++++++++++++++++--
> 1 file changed, 44 insertions(+), 2 deletions(-)
>
> diff --git a/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
> b/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
> index 6e14c1f..7000e2e 100644
> --- a/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
> +++ b/MdeModulePkg/Universal/Network/MnpDxe/MnpVlan.c
> @@ -228,10 +228,51 @@ MnpInsertVlanTag (
> VlanTci->Bits.Cfi = VLAN_TCI_CFI_CANONICAL_MAC;
> VlanTci->Bits.Priority = MnpServiceData->Priority;
> VlanTci->Uint16 = HTONS (VlanTci->Uint16);
> }
>
> +/**
> + Check VLAN configuration variable and delete the duplicative
> +content if
> has identical Vlan ID.
> +
> + @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.
> +
> +**/
> +VOID
> +MnpCheckVlanVariable (
> + IN VLAN_TCI *Buffer,
> + IN UINTN NumberOfVlan,
> + OUT UINTN *NewNumberOfVlan
> + )
> +{
> + UINTN Index;
> + UINTN Index2;
> + UINTN Count;
> + BOOLEAN FoundDuplicateItem;
> +
> + Count = 0;
> + FoundDuplicateItem = FALSE;
> +
> + 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++;
> + continue;
> + }
> + }
> + if (FoundDuplicateItem) {
> + for (Index2 = Index +1; Index2 < NumberOfVlan; Index++, Index2++) {
> + CopyMem (Buffer + Index, Buffer + Index2, sizeof (VLAN_TCI));
> + }
> + }
> + FoundDuplicateItem = FALSE;
> + }
> +
> + *NewNumberOfVlan = NumberOfVlan - Count; }
>
> /**
> Get VLAN configuration variable.
>
> @param[in] MnpDeviceData Pointer to the MNP device context data.
> @@ -253,10 +294,11 @@ MnpGetVlanVariable (
> )
> {
> UINTN BufferSize;
> EFI_STATUS Status;
> VLAN_TCI *Buffer;
> + UINTN NewNumberOfVlan;
>
> //
> // Get VLAN configuration from EFI Variable
> //
> Buffer = NULL;
> @@ -290,17 +332,17 @@ MnpGetVlanVariable (
> if (EFI_ERROR (Status)) {
> FreePool (Buffer);
> return Status;
> }
>
> - *NumberOfVlan = BufferSize / sizeof (VLAN_TCI);
> + MnpCheckVlanVariable (Buffer, BufferSize / sizeof (VLAN_TCI),
> &NewNumberOfVlan);
> + *NumberOfVlan = NewNumberOfVlan;
> *VlanVariable = Buffer;
>
> return Status;
> }
>
> -
> /**
> Set VLAN configuration variable.
>
> @param[in] MnpDeviceData Pointer to the MNP device context data.
> @param[in] NumberOfVlan Number of VLAN in array VlanVariable.
> --
> 1.9.5.msysgit.1
>
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