From 2ce5c88a7adaea3eeeccc932b18da5f02440f8cd Mon Sep 17 00:00:00 2001
From: vanjeff <vanjeff@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 14 Aug 2009 02:37:23 +0000
Subject: [PATCH 1/1] Use siaddr in DHCP packet, if zero, use option 54
 instead.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9066 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcDhcp.c | 7 ++++---
 MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c | 6 ++++--
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcDhcp.c b/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcDhcp.c
index 1d5557f7a9..5e86cf5779 100644
--- a/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcDhcp.c
+++ b/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcDhcp.c
@@ -275,10 +275,11 @@ PxeBcTryBinl (
   Offer = &Private->Dhcp4Offers[Index].Packet.Offer;
 
   //
-  // use option 54, if zero, use siaddr in header
+  // Use siaddr(next server) in DHCPOFFER packet header, if zero, use option 54(server identifier)
+  // in DHCPOFFER packet.
+  // (It does not comply with PXE Spec, Ver2.1)
   //
-  ZeroMem (&ServerIp, sizeof(EFI_IP_ADDRESS));
-  if (Private->Dhcp4Offers[Index].Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_SERVER_ID] != NULL) {
+  if (EFI_IP4_EQUAL (&Offer->Dhcp4.Header.ServerAddr.Addr, &mZeroIp4Addr)) {
     CopyMem (
       &ServerIp.Addr[0],
       Private->Dhcp4Offers[Index].Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_SERVER_ID]->Data,
diff --git a/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c b/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
index 3eeacdcc5c..659f638930 100644
--- a/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
+++ b/MdeModulePkg/Universal/Network/UefiPxeBcDxe/PxeBcImpl.c
@@ -2480,9 +2480,11 @@ DiscoverBootFile (
   }
 
   //
-  // use option 54, if zero, use siaddr in header
+  // Use siaddr(next server) in DHCPOFFER packet header, if zero, use option 54(server identifier)
+  // in DHCPOFFER packet.
+  // (It does not comply with PXE Spec, Ver2.1)
   //
-  if (Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_SERVER_ID] != NULL) {
+  if (EFI_IP4_EQUAL (&Packet->Packet.Offer.Dhcp4.Header.ServerAddr, &mZeroIp4Addr)) {
     CopyMem (
       &Private->ServerIp,
       Packet->Dhcp4Option[PXEBC_DHCP4_TAG_INDEX_SERVER_ID]->Data,
-- 
2.39.2