pidl decode/encode from/to buffer

[Martin Vogt]

Hello,

I'm currently writing a IDL based smartcard interface for freerdp:

http://www.freerdp.com/
http://msdn.microsoft.com/en-us/library/cc242792%28v=PROT.10%29.aspx

with Visual Studio (and midl) everything works fine, but now I like to
use pidl for linux in a similar way like Microsoft midl.

midl has the option to do the serialization to/from a buffer, they
call it "pickle" and in the windows SDK there is an example for it.
(writing a structure as "wire" data into a file and reading
it back from the file into the structure)

The setup with midl is like this: (first define the structures
for marshalling)
sc.idl:

[
    uuid(A35AF600-9CF4-11CD-A076-08002B2BD711),
    version(1.0),
    pointer_default(unique)
]
interface IRepresentation
{

typedef struct _REDIR_SCARDCONTEXT
{
    [range(0, 16)]                  unsigned long       cbContext;
    [unique] [size_is(cbContext)]   byte               *pbContext;
} REDIR_SCARDCONTEXT;

typedef struct _EstablishContext_Call
{
    unsigned long                               dwScope;
} EstablishContext_Call;

typedef struct _EstablishContext_Return
{
    long                                        ReturnCode;
    REDIR_SCARDCONTEXT                          Context;
} EstablishContext_Return;
}

then put additional information into an .ACF file (which is evaluated by
midl). This adds generic functions for marshalling from/to buffers, with
handles.
sc.acf:

interface IRepresentation
{
   typedef [encode, decode] EstablishContext_Call;
   typedef [encode, decode] EstablishContext_Return;
}

with these options in the ACL file "encode,decode" the midl
compiler will now generate interfaces for decoding/encoding from/to
a buffer:

sc_c.c:
EstablishContext_Call_Encode(handle_t _MidlEsHandle,
                             EstablishContext_Call *_pType)
EstablishContext_Call_Decode(handle_t _MidlEsHandle,
                             EstablishContext_Call * _pType)
EstablishContext_Return_Encode(handle_t _MidlEsHandle,
                               EstablishContext_Return * _pType)
EstablishContext_Return_Decode(handle_t _MidlEsHandle,
                               EstablishContext_Return * _pType)

And the handles are (more or less) callbacks for marshalling:

created with:

MesEncodeIncrementalHandleCreate
MesDecodeIncrementalHandleCreate

The C interfaces are: MIDL_ES_READ,MIDL_ES_ALLOC,MIDL_ES_WRITE


These generated interface, plus some additional serialization buffers
then should be used in freerdp to decode/encode the wire data,
based on the IDL file.

Is there a similar way to achieve this kind of serialization from/to a
buffer with pidl?


regards,

Martin