NetworkPkg: Fix the issue EfiPxeBcDhcp() may return wrong status.

if the instance of the EFI DHCP4 protocol driver is in the Dhcp4Bound status
that is DHCP configuration has completed, so the Dhcp4->Start FUNC in
the PxeBcDhcpDora() will return EFI_ALREADY_STARTED status which lead to
EfiPxeBcDhcp FUNC not in correspondence with UEFI spec.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Zhang Lubo <lubo.zhang@intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
[lersek@redhat.com: updated copyright year as requested by Siyuan]
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18049 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c
index df171598b1b19f3bf356ab8560e5df57300af580..c0277706f2aae21f51cd57a1569d0de4aa58ca8b 100644 (file)
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c
@@ -1,7 +1,7 @@
 /** @file\r
   Functions implementation related with DHCPv4 for UefiPxeBc Driver.\r
 \r
-  Copyright (c) 2009 - 2014, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>\r
 \r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -1569,10 +1569,12 @@ PxeBcDhcp4Dora (
   ZeroMem (Private->OfferIndex, sizeof (Private->OfferIndex));\r
 \r
   //\r
-  // Start DHCPv4 D.O.R.A. process to acquire IPv4 address.\r
+  // Start DHCPv4 D.O.R.A. process to acquire IPv4 address. This may \r
+  // have already been done, thus do not leave in error if the return\r
+  // code is EFI_ALREADY_STARTED.\r
   //\r
   Status = Dhcp4->Start (Dhcp4, NULL);\r
-  if (EFI_ERROR (Status)) {\r
+  if (EFI_ERROR (Status) && Status != EFI_ALREADY_STARTED) {\r
     if (Status == EFI_ICMP_ERROR) {\r
       PxeMode->IcmpErrorReceived = TRUE;\r
     }\r