WinCE Ethernet(NDIS 5.1)

Madhura
Hi,

I have few queries related to Ethernet(NDIS) in the WINCE 6.0.

I am writing code for a an Ethernet device where i need to 
implement the Offloading the Segmentation of Large TCP Packets.
There is no reference driver code. E100BEX is given in WinCE 6.0
shared directry, but its not helpful, as they are calculating in 
driver code itself. I need some functions where i can access the
TSO Packet info.
 
As there are some api's provided by linux for getting the packet info.
Like : 1. MSS count,
       2. Fragment count,
       3. Payload length, 
       4. TCP/IP header Length,
       5. Offset at which Checksum of TCP, IP start.

I got api's for ,
1.MSS count, 2. Fragment count, 3.TCP Header length.

But Can I get other api's in NDIS WinCE also?
1. Payload length,
2. IP header length,
3. Offset at which checksum starts.

If there are functions which provide it will be good.
And if not should i need to calculate manually all these, if so
can any one get me reference code?