Re: [Patch] NetworkPkg: Fix PXEv6 boot failure when DhcpBinl offer received.

["Fu, Siyuan" <siyuan.fu@intel.com>]

Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>

-----Original Message-----
From: Wu, Jiaxin 
Sent: Thursday, April 27, 2017 9:51 AM
To: edk2-devel@lists.01.org
Cc: Ye, Ting; Fu, Siyuan; Wu, Jiaxin
Subject: [Patch] NetworkPkg: Fix PXEv6 boot failure when DhcpBinl offer received.

In case of the DHCP and PXE services on different servers,PXEv6 boot will failure when DhcpBinl offer received. The issue is caused by the following
reasons:
* PXE Client doesn't append VENDOR_CLASS request parameter, so the offer replied from DHCP service will not contain VENDOR_CLASS option (16).
* Once the DhcpBinl offer is selected, the boot discover message should be sent out to request the bootfile by this offer. Current implementation always use servers multi-cast address instead of BootFileUrl address in
dhcp6 offer. we should check it first, then decide whether use multi-cast address or not.
* If DhcpBinl offer is selected, the boot discover message shouldn't find server ID Option from DhcpBinl offer. That's incorrect because DHCP service and PXE service on different servers. In such a case, we can ignore the Server ID Option.

With the above fix in the patch, PXEv6 can boot successfully when DhcpBinl offer received.

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>
---
 NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c | 43 +++++++++++++++++++-----------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
index 4cd1770..f2239fd 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp6.c
@@ -91,15 +91,16 @@ PxeBcBuildDhcp6Options (
 
   //
   // Append client option request option
   //
   OptList[Index]->OpCode     = HTONS (DHCP6_OPT_ORO);
-  OptList[Index]->OpLen      = HTONS (6);
+  OptList[Index]->OpLen      = HTONS (8);
   OptEnt.Oro                 = (PXEBC_DHCP6_OPTION_ORO *) OptList[Index]->Data;
   OptEnt.Oro->OpCode[0]      = HTONS(DHCP6_OPT_BOOT_FILE_URL);
   OptEnt.Oro->OpCode[1]      = HTONS(DHCP6_OPT_BOOT_FILE_PARAM);
   OptEnt.Oro->OpCode[2]      = HTONS(DHCP6_OPT_DNS_SERVERS);
+  OptEnt.Oro->OpCode[3]      = HTONS(DHCP6_OPT_VENDOR_CLASS);
   Index++;
   OptList[Index]             = GET_NEXT_DHCP6_OPTION (OptList[Index - 1]);
 
   //
   // Append client network device interface option @@ -905,16 +906,16 @@ PxeBcRequestBootService (
   UINTN                               ReadSize;
   UINT16                              OpFlags;
   UINT16                              OpCode;
   UINT16                              OpLen;
   EFI_STATUS                          Status;
-  EFI_DHCP6_PACKET                    *ProxyOffer;
+  EFI_DHCP6_PACKET                    *IndexOffer;
   UINT8                               *Option;
 
   PxeBc       = &Private->PxeBc;
   Request     = Private->Dhcp6Request;
-  ProxyOffer = &Private->OfferBuffer[Index].Dhcp6.Packet.Offer;
+  IndexOffer  = &Private->OfferBuffer[Index].Dhcp6.Packet.Offer;
   SrcPort     = PXEBC_BS_DISCOVER_PORT;
   DestPort    = PXEBC_BS_DISCOVER_PORT;
   OpFlags     = 0;
 
   if (Request == NULL) {
@@ -927,36 +928,38 @@ PxeBcRequestBootService (
   }
 
   //
   // Build the request packet by the cached request packet before.
   //
-  Discover->TransactionId = ProxyOffer->Dhcp6.Header.TransactionId;
+  Discover->TransactionId = IndexOffer->Dhcp6.Header.TransactionId;
   Discover->MessageType   = Request->Dhcp6.Header.MessageType;
   RequestOpt              = Request->Dhcp6.Option;
   DiscoverOpt             = Discover->DhcpOptions;
   DiscoverLen             = sizeof (EFI_DHCP6_HEADER);
   RequestLen              = DiscoverLen;
 
   //
   // Find Server ID Option from ProxyOffer.
   //
-  Option = PxeBcDhcp6SeekOption (
-             ProxyOffer->Dhcp6.Option,
-             ProxyOffer->Length - 4,
-             DHCP6_OPT_SERVER_ID
-             );
-  if (Option == NULL) {
-    return EFI_NOT_FOUND;
-  }
+  if (Private->OfferBuffer[Index].Dhcp6.OfferType == PxeOfferTypeProxyBinl) {  
+    Option = PxeBcDhcp6SeekOption (
+               IndexOffer->Dhcp6.Option,
+               IndexOffer->Length - 4,
+               DHCP6_OPT_SERVER_ID
+               );
+    if (Option == NULL) {
+      return EFI_NOT_FOUND;
+    }
   
-  //
-  // Add Server ID Option.
-  //
-  OpLen = NTOHS (((EFI_DHCP6_PACKET_OPTION *) Option)->OpLen);
-  CopyMem (DiscoverOpt, Option, OpLen + 4);
-  DiscoverOpt += (OpLen + 4);
-  DiscoverLen += (OpLen + 4);
+    //
+    // Add Server ID Option.
+    //
+    OpLen = NTOHS (((EFI_DHCP6_PACKET_OPTION *) Option)->OpLen);
+    CopyMem (DiscoverOpt, Option, OpLen + 4);
+    DiscoverOpt += (OpLen + 4);
+    DiscoverLen += (OpLen + 4);
+  }
 
   while (RequestLen < Request->Length) {
     OpCode = NTOHS (((EFI_DHCP6_PACKET_OPTION *) RequestOpt)->OpCode);
     OpLen  = NTOHS (((EFI_DHCP6_PACKET_OPTION *) RequestOpt)->OpLen);
     if (OpCode != EFI_DHCP6_IA_TYPE_NA && @@ -1076,11 +1079,11 @@ PxeBcRetryDhcp6Binl (
           Private->OfferBuffer[Index].Dhcp6.OfferType == PxeOfferTypeProxyBinl);
 
   Mode                  = Private->PxeBc.Mode;
   Private->IsDoDiscover = FALSE;
   Offer                 = &Private->OfferBuffer[Index].Dhcp6;
-  if (Offer->OfferType == PxeOfferTypeDhcpBinl) {
+  if (Offer->OptList[PXEBC_DHCP6_IDX_BOOT_FILE_URL] == NULL) {
     //
     // There is no BootFileUrl option in dhcp6 offer, so use servers multi-cast address instead.
     //
     CopyMem (
       &Private->ServerIp.v6,
--
1.9.5.msysgit.1