[Change summary]:

1. Update NetLib to a combined NetLib support dual network stack:
1) Add Network Debug facility for IPv4 stack.
2) Extend the library APIs to support IPv6 stack:
   a. NetIp6IsUnspecifiedAddr
   b. NetIp6IsLinkLocalAddr   
   c. NetIp6IsNetEqual
   d. NetLibCreateIPv6DPathNode.
   e. NetIp6PseudoHeadChecksum
   f. NetIp6IsValidUnicast
3) Update the structure definitions:
   a. Update NET_BUF to add EFI_IP6_HEADER and EFI_UDP_HEADER
   b. Add NET_IP6_PSEUDO_HDR
4) Update Ip4IsUnicast to NetIp4IsUnicast

2. Update the impacted modules to adopt the combined NetLib.

3. Clean up coding style errors in all network drivers and libraries.


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9391 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Library/DxeNetLib/NetBuffer.c

@@ -1803,3 +1803,41 @@ NetPseudoHeadChecksum (
 
   return NetblockChecksum ((UINT8 *) &Hdr, sizeof (Hdr));
 }
+
+/**
+  Compute the checksum for TCP6/UDP6 pseudo header. 
+   
+  Src and Dst are in network byte order, and Len is in host byte order.
+
+  @param[in]   Src                   The source address of the packet.
+  @param[in]   Dst                   The destination address of the packet.
+  @param[in]   NextHeader            The protocol type of the packet.
+  @param[in]   Len                   The length of the packet.
+
+  @return   The computed checksum.
+
+**/
+UINT16
+NetIp6PseudoHeadChecksum (
+  IN EFI_IPv6_ADDRESS       *Src,
+  IN EFI_IPv6_ADDRESS       *Dst,
+  IN UINT8                  NextHeader,
+  IN UINT32                 Len
+  )
+{
+  NET_IP6_PSEUDO_HDR        Hdr;
+
+  //
+  // Zero the memory to relieve align problems
+  //
+  ZeroMem (&Hdr, sizeof (Hdr));
+
+  IP6_COPY_ADDRESS (&Hdr.SrcIp, Src);
+  IP6_COPY_ADDRESS (&Hdr.DstIp, Dst);
+
+  Hdr.NextHeader = NextHeader;
+  Hdr.Len        = HTONL (Len); 
+
+  return NetblockChecksum ((UINT8 *) &Hdr, sizeof (Hdr));
+}
+