[Patch 3/3] NetworkPkg/UefiPxeBcDxe: Allow the NULL configuration for NewStationIP/NewSubnetMask

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

According the UEFI Spec for PxeBc.SetStationIP():
If NewStationIP is NULL, then the current IP address will not be modified.
...
If NewSubnetMask is NULL, then the current subnet mask will not be modified.

Currently, EfiPxeBcSetStationIP() doesn't comply with UEFI Spec. This patch is
to fix the issue.

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/PxeBcSupport.c | 24 ++++++++++++++----------
 NetworkPkg/UefiPxeBcDxe/PxeBcSupport.h |  4 ++--
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.c b/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.c
index 538cb59..52f1e92 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.c
@@ -28,26 +28,26 @@
 
 **/
 EFI_STATUS
 PxeBcFlushStationIp (
   PXEBC_PRIVATE_DATA       *Private,
-  EFI_IP_ADDRESS           *StationIp,
+  EFI_IP_ADDRESS           *StationIp,     OPTIONAL
   EFI_IP_ADDRESS           *SubnetMask     OPTIONAL
   )
 {
   EFI_PXE_BASE_CODE_MODE   *Mode;
   EFI_STATUS               Status;
 
-  ASSERT (StationIp != NULL);
-
   Mode   = Private->PxeBc.Mode;
   Status = EFI_SUCCESS;
 
   if (Mode->UsingIpv6) {
 
-    CopyMem (&Private->Udp6CfgData.StationAddress, StationIp, sizeof (EFI_IPv6_ADDRESS));
-    CopyMem (&Private->Ip6CfgData.StationAddress, StationIp, sizeof (EFI_IPv6_ADDRESS));
+    if (StationIp != NULL) {
+      CopyMem (&Private->Udp6CfgData.StationAddress, StationIp, sizeof (EFI_IPv6_ADDRESS));
+      CopyMem (&Private->Ip6CfgData.StationAddress, StationIp, sizeof (EFI_IPv6_ADDRESS));
+    }
 
     //
     // Reconfigure the Ip6 instance to capture background ICMP6 packets with new station Ip address.
     //
     Private->Ip6->Cancel (Private->Ip6, &Private->Icmp6Token);
@@ -58,15 +58,19 @@ PxeBcFlushStationIp (
       goto ON_EXIT;
     }
 
     Status = Private->Ip6->Receive (Private->Ip6, &Private->Icmp6Token);
   } else {
-    ASSERT (SubnetMask != NULL);
-    CopyMem (&Private->Udp4CfgData.StationAddress, StationIp, sizeof (EFI_IPv4_ADDRESS));
-    CopyMem (&Private->Udp4CfgData.SubnetMask, SubnetMask, sizeof (EFI_IPv4_ADDRESS));
-    CopyMem (&Private->Ip4CfgData.StationAddress, StationIp, sizeof (EFI_IPv4_ADDRESS));
-    CopyMem (&Private->Ip4CfgData.SubnetMask, SubnetMask, sizeof (EFI_IPv4_ADDRESS));
+    if (StationIp != NULL) {
+      CopyMem (&Private->Udp4CfgData.StationAddress, StationIp, sizeof (EFI_IPv4_ADDRESS));
+      CopyMem (&Private->Ip4CfgData.StationAddress, StationIp, sizeof (EFI_IPv4_ADDRESS));
+    }
+    
+    if (SubnetMask != NULL) {
+      CopyMem (&Private->Udp4CfgData.SubnetMask, SubnetMask, sizeof (EFI_IPv4_ADDRESS));
+      CopyMem (&Private->Ip4CfgData.SubnetMask, SubnetMask, sizeof (EFI_IPv4_ADDRESS));
+    }
 
     //
     // Reconfigure the Ip4 instance to capture background ICMP packets with new station Ip address.
     //
     Private->Ip4->Cancel (Private->Ip4, &Private->IcmpToken);
diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.h b/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.h
index b8519ae..17bee5c 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.h
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcSupport.h
@@ -1,9 +1,9 @@
 /** @file
   Support functions declaration for UefiPxeBc Driver.
 
-  Copyright (c) 2007 - 2016, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2007 - 2017, Intel Corporation. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
   http://opensource.org/licenses/bsd-license.php.
@@ -38,11 +38,11 @@
 
 **/
 EFI_STATUS
 PxeBcFlushStationIp (
   PXEBC_PRIVATE_DATA       *Private,
-  EFI_IP_ADDRESS           *StationIp,
+  EFI_IP_ADDRESS           *StationIp,     OPTIONAL
   EFI_IP_ADDRESS           *SubnetMask     OPTIONAL
   );
 
 
 /**
-- 
1.9.5.msysgit.1