NetworkPkg: Record user configured TargetIP/Port in iBFT

Current ISCSI driver records redirected iSCSI targetIP/Port in iBFT
once redirection occurs, which removes the possibility of the OS
to reconnect to the configured IP for load balancing. The behavior
is not explicitly described in IBFT spec, though the MSFT expert
confirm we should record original user setting rather than
publish the redirected IP.

Thanks Sriram for reviewing and validating this patch in his test-bed.

Cc: Subramanian Sriram <sriram-s@hpe.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Zhang Lubo <lubo.zhang@intel.com>

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ye Ting <ting.ye@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Subramanian Sriram <sriram-s@hpe.com>

NetworkPkg/IScsiDxe/IScsiMisc.h

@@ -50,9 +50,14 @@ typedef struct _ISCSI_SESSION_CONFIG_NVDATA {
   UINT8             PrefixLength;
   UINT8             BootLun[8];
 
-  UINT16            ConnectTimeout; ///< timout value in milliseconds
+  UINT16            ConnectTimeout; ///< timout value in milliseconds.
   UINT8             ConnectRetryCount;
   UINT8             IsId[6];
+
+  BOOLEAN           RedirectFlag;
+  UINT16            OriginalTargetPort;     // The port of proxy/virtual target.
+  EFI_IP_ADDRESS    OriginalTargetIp;       // The address of proxy/virtual target.
+  
 } ISCSI_SESSION_CONFIG_NVDATA;
 #pragma pack()