Re: [Patch] MdeModulePkg/SnpDxe: Check the value of Nii->Id before use it directly.

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

Thanks to catch that.  The UNDI is started by SNP driver. Then, Nii->Id changes to the none-zero value. But currently, UNDI seems not follow that.  


> -----Original Message-----
> From: Fu, Siyuan
> Sent: Thursday, December 21, 2017 3:39 PM
> To: Wu, Jiaxin <jiaxin.wu@intel.com>; edk2-devel@lists.01.org
> Cc: Wang, Fan <fan.wang@intel.com>; Ye, Ting <ting.ye@intel.com>
> Subject: RE: [Patch] MdeModulePkg/SnpDxe: Check the value of Nii->Id
> before use it directly.
> 
> Hi, Jiaxin
> 
> In the line you are modifying the UDNI is always not started. You should
> move the Nii->Id to the line after PxeStart(), not to check it here.
> 
> BestRegards
> Fu Siyuan
> 
> > -----Original Message-----
> > From: Wu, Jiaxin
> > Sent: Thursday, December 21, 2017 3:13 PM
> > To: edk2-devel@lists.01.org
> > Cc: Wang, Fan <fan.wang@intel.com>; Ye, Ting <ting.ye@intel.com>; Fu,
> > Siyuan <siyuan.fu@intel.com>; Wu, Jiaxin <jiaxin.wu@intel.com>
> > Subject: [Patch] MdeModulePkg/SnpDxe: Check the value of Nii->Id
> before
> > use it directly.
> >
> > Nii->Id is the address of the first byte of the identifying structure
> > for this network interface. This is only valid when the network interface
> > is started. When the network interface is not started, this field is set
> > to zero. So, we should check the value of Nii->Id before use it directly.
> >
> > Cc: Wang Fan <fan.wang@intel.com>
> > Cc: Ye Ting <ting.ye@intel.com>
> > Cc: Fu Siyuan <siyuan.fu@intel.com>
> > Contributed-under: TianoCore Contribution Agreement 1.0
> > Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
> > ---
> >  MdeModulePkg/Universal/Network/SnpDxe/Snp.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
> > b/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
> > index 9f61aee..f0257a2 100644
> > --- a/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
> > +++ b/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
> > @@ -1,9 +1,9 @@
> >  /** @file
> >    Implementation of driver entry point and driver binding protocol.
> >
> > -Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR>
> > +Copyright (c) 2004 - 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
> > which
> >  accompanies this distribution. The full text of the license may be found
> > at
> >  http://opensource.org/licenses/bsd-license.php
> >
> > @@ -333,10 +333,15 @@ SimpleNetworkDriverStart (
> >      return Status;
> >    }
> >
> >    DEBUG ((EFI_D_INFO, "Start(): UNDI3.1 found\n"));
> >
> > +  if (Nii->Id == 0) {
> > +    DEBUG ((EFI_D_NET, "\nUNDI is not started.\n"));
> > +    goto NiiError;
> > +  }
> > +
> >    Pxe = (PXE_UNDI *) (UINTN) (Nii->Id);
> >
> >    if (Calc8BitCksum (Pxe, Pxe->hw.Len) != 0) {
> >      DEBUG ((EFI_D_NET, "\n!PXE checksum is not correct.\n"));
> >      goto NiiError;
> > --
> > 1.9.5.msysgit.1