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

[Guo Heyi <heyi.guo@linaro.org>]

Not yet; I can do that right now.

Regards,

Gary (Heyi Guo)

On Wed, Dec 13, 2017 at 07:39:21AM +0000, Wu, Jiaxin wrote:
> 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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