Re: MdeModulePkg/UefiPxeBcDxe: Question about IcmpErrorListenHandler in PxeBcImpl.c

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

Hi Gary,

Do you have reported the Bugzilla for this issue? If not, can you report one for it?

Thank you very much!
Jiaxin



> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> Guo Heyi
> Sent: Monday, December 11, 2017 6:43 PM
> To: Wu, Jiaxin <jiaxin.wu@intel.com>
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Dong, Eric <eric.dong@intel.com>; edk2-
> devel@lists.01.org; Wu, Jiaxin <jiaxin.wu@intel.com>; Fu, Siyuan
> <siyuan.fu@intel.com>; Zeng, Star <star.zeng@intel.com>
> Subject: Re: [edk2] MdeModulePkg/UefiPxeBcDxe: Question about
> IcmpErrorListenHandler in PxeBcImpl.c
> 
> Hi Jiaxin,
> 
> We tested and the patch worked. We also tested PXE boot and no new issue
> was observed.
> 
> Thanks and regards,
> 
> Gary (Heyi Guo)
> 
> 
> On Thu, Dec 07, 2017 at 08:20:28PM +0800, Heyi Guo wrote:
> >
> >
> > 在 12/7/2017 6:40 PM, Wu, Jiaxin 写道:
> > >>You say "IcmpErrorRcvToken is only used to get ICMP error from IP
> > >>layer", does that mean only ICMP error packets will go to
> > >>IcmpErrorListenHandler?
> > >>If it is the case, how do we make it? I can only find a simple
> > >>Ip4->Receive is called to receive IP4 packets; how are other types of
> > >>IP4 packets filtered out?
> > >No, all of the *ICMP* packets with the same station IP address will go to
> IcmpErrorListenHandler() callback function. Because PXE driver has already
> configured the current IP protocol only receive the ICMP packets:
> > >	ZeroMem (&Private->Ip4ConfigData, sizeof
> (EFI_IP4_CONFIG_DATA));
> > >   	Private->Ip4ConfigData.DefaultProtocol   = EFI_IP_PROTO_ICMP;
> > >   	Private->Ip4ConfigData.AcceptIcmpErrors  = TRUE;
> > >	Ip4ConfigData.DefaultProtocol   = EFI_IP_PROTO_ICMP;
> > >So, it is only used to capture background ICMP packets (Including the
> ICMP error message) with the same station IP address.
> > Many thanks; it explains my question clearly.
> >
> > >
> > >>If it is not, why don't we need to filter the packets in
> > >>IcmpErrorListenHandler? If we recycle the packets in
> > >>IcmpErrorListenHandler, will it cause the upper layer of protocols fail
> > >>to fetch RxData?
> > >IcmpErrorListenHandler() should filter the packets and only handle the
> ICMP error message. But currently, the code logic is incorrect. I generated
> one patch as attached one for your reference, can you help to verify
> whether it works or not? (Ignore my previous suggestion check).
> > Sure we can verify it.
> > >In my opinion, the RxData should be recycled since it has been recorded in
> Mode->IcmpError.
> > Agree.
> >
> > Thanks,
> >
> > Gary (Heyi Guo)
> > >
> > >Thanks,
> > >Jiaxin
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >>-----Original Message-----
> > >>From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf
> Of
> > >>Heyi Guo
> > >>Sent: Thursday, December 7, 2017 4:18 PM
> > >>To: Wu, Jiaxin <jiaxin.wu@intel.com>; edk2-devel@lists.01.org
> > >>Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>;
> Dong,
> > >>Eric <eric.dong@intel.com>; Zeng, Star <star.zeng@intel.com>
> > >>Subject: Re: [edk2] MdeModulePkg/UefiPxeBcDxe: Question about
> > >>IcmpErrorListenHandler in PxeBcImpl.c
> > >>
> > >>Hi Jiaxin,
> > >>
> > >>Thanks for your reply.
> > >>
> > >>You say "IcmpErrorRcvToken is only used to get ICMP error from IP
> > >>layer", does that mean only ICMP error packets will go to
> > >>IcmpErrorListenHandler?
> > >>
> > >>If it is the case, how do we make it? I can only find a simple
> > >>Ip4->Receive is called to receive IP4 packets; how are other types of
> > >>IP4 packets filtered out?
> > >>
> > >>If it is not, why don't we need to filter the packets in
> > >>IcmpErrorListenHandler? If we recycle the packets in
> > >>IcmpErrorListenHandler, will it cause the upper layer of protocols fail
> > >>to fetch RxData?
> > >>
> > >>Please forgive me if my questions are too stupid :)
> > >>
> > >>Regards,
> > >>
> > >>Gary (Heyi Guo)
> > >>
> > >>
> > >>在 12/7/2017 3:48 PM, Wu, Jiaxin 写道:
> > >>>Hi Gary,
> > >>>
> > >>>IcmpErrorRcvToken is only used to get ICMP error from IP layer, and
> the
> > >>data will be copied to Mode->IcmpError. So, I think the RxData should be
> > >>recycled.
> > >>>Besides, EFI_IP_PROTO_ICMP should be also checked in the call
> function
> > >>but currently it's not:
> > >>>    if (!EFI_IP4_EQUAL (&RxData->Header->DestinationAddress,
> &Mode-
> > >>>StationIp.v4)) {
> > >>>      //
> > >>>      // The dest address is not equal to Station Ip address, discard it.
> > >>>      //
> > >>>      goto CleanUp;
> > >>>    }
> > >>>
> > >>>    +if (&RxData->Header->Protocol != EFI_IP_PROTO_ICMP) {
> > >>>    +//
> > >>>    +// The protocol value in the header of the receveid packet should
> be
> > >>EFI_IP_PROTO_ICMP.
> > >>>    +//
> > >>>    +goto CleanUp;
> > >>>    +}
> > >>>
> > >>>Thanks the report.
> > >>>
> > >>>Thanks,
> > >>>Jiaxin
> > >>>
> > >>>
> > >>>
> > >>>>-----Original Message-----
> > >>>>From: Guo Heyi [mailto:heyi.guo@linaro.org]
> > >>>>Sent: Thursday, December 7, 2017 12:07 PM
> > >>>>To: edk2-devel@lists.01.org
> > >>>>Cc: Zeng, Star <star.zeng@intel.com>; Dong, Eric
> <eric.dong@intel.com>;
> > >>Ni,
> > >>>>Ruiyu <ruiyu.ni@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>; Wu,
> Jiaxin
> > >>>><jiaxin.wu@intel.com>
> > >>>>Subject: MdeModulePkg/UefiPxeBcDxe: Question about
> > >>>>IcmpErrorListenHandler in PxeBcImpl.c
> > >>>>
> > >>>>Hi folks,
> > >>>>
> > >>>>In PxeBcImpl.c, we have IcmpErrorListenHandler which seems to
> process
> > >>>>ICMP errors. But in EfiPxeBcStart function, we can see Private-
> > >>>>>IcmpErrorRcvToken.Event is only a common event and Ip4->Receive
> is
> > >>>>called to receive IP4 packets. So will IcmpErrorListenHandler receive all
> IP4
> > >>>>packets belonging to this network interface, or will it only receive
> ICMP
> > >>error
> > >>>>packets? If it is the latter situation, how do we make it?
> > >>>>
> > >>>>The background of this question is that when we flush the network
> with
> > >>>>deprecated ICMP packets (type 15, 16, ...), RxData will not be recycled
> and
> > >>>>the list of UEFI events becomes longer and longer, which finally
> impacts
> > >>>>system performance a lot. If only error ICMP will be received by
> > >>>>IcmpErrorListenHandler, we'd like to patch it as below:
> > >>>>
> > >>>>diff --git
> > >>a/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
> > >>>>b/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
> > >>>>index 6d4f33f..f74b264 100644
> > >>>>--- a/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
> > >>>>+++
> b/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
> > >>>>@@ -216,8 +216,6 @@ IcmpErrorListenHandlerDpc (
> > >>>>       CopiedPointer += CopiedLen;
> > >>>>     }
> > >>>>
> > >>>>-  goto Resume;
> > >>>>-
> > >>>>   CleanUp:
> > >>>>     gBS->SignalEvent (RxData->RecycleSignal);
> > >>>>
> > >>>>We tested and it worked, but we are still not sure whether it will
> impact
> > >>>>other code in the network stack.
> > >>>>
> > >>>>Please let me know your comments.
> > >>>>
> > >>>>Thanks,
> > >>>>
> > >>>>Gary (Heyi Guo)
> > >>_______________________________________________
> > >>edk2-devel mailing list
> > >>edk2-devel@lists.01.org
> > >>https://lists.01.org/mailman/listinfo/edk2-devel
> >
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