I'm not aware of any method that lets you go from a managed byte array to
struct.  Marshal.PtrToStructure takes an unmanaged pointer and changes it to
struct.  You could possibly try casting your byte[] as byte* (unsafe
required) and seeing if Marshal.PtrToStructure will handle it.

Other than that your stuck with something like this:

BinaryReader:
byte[] buffer = new byte[size];
s.Receive(buffer, size, 0);
MemoryStream bin = new MemoryStream(buffer);
BinaryReader din = new BinaryReader(bin);

/* Read each field using the reader's methods */

You could probably implement this generically using reflection.  If you do,
post us a copy :)

Cole