Re: [RFC 2/4] spdm: add spdm storage transport virtual header

[Wilfred Mallawa]

On Fri, 2025-01-10 at 10:04 +0100, Klaus Jensen wrote:
> On Jan  7 15:29, Wilfred Mallawa via wrote:
> > This header contains the transport encoding for an SPDM message
> > that
> > uses the SPDM over Storage transport as defined by the DMTF
> > DSP0286.
> > 
> > Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
> > ---
> >  include/system/spdm-socket.h | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/include/system/spdm-socket.h b/include/system/spdm-
> > socket.h
> > index 2b7d03f82d..fc007e5b48 100644
> > --- a/include/system/spdm-socket.h
> > +++ b/include/system/spdm-socket.h
> > @@ -88,6 +88,18 @@ bool spdm_socket_send(const int socket, uint32_t
> > socket_cmd,
> >   */
> >  void spdm_socket_close(const int socket, uint32_t transport_type);
> >  
> > +/*
> > + * Defines the transport encoding for SPDM, this information shall
> > be passed
> > + * down to the SPDM server, when conforming to the SPDM over
> > Storage standard
> > + * as defined by DSP0286.
> > + */
> > +typedef struct QEMU_PACKED {
> > +    uint8_t security_protocol;
> > +    uint16_t security_protocol_specific;
> > +    bool inc_512;
> > +    uint32_t length;
> > +} StorageSpdmTransportHeader;
> 
> Does it make sense to pack a bool? Is this defined by the SPDM server
> in
> use? I can't find the definition of this header anywhere.
> 
This is essentially a virtual header containing essential storage
transport data as per DSP0286. For example, this is defined in the
upstream effort for 
`libspmd` to add storage binding support [1] and in DSP0286 [2], this
is defined in section 5.1.1.

Current implementation of the SPDM server (i.e in `spdm-utils` only one
to have support for storage), will just pass this header to `libspdm`
to be decoded. Once decoded by `libspdm`, `spdm-utils`/server will
contextually check for validity of the message.

As for inc_512, it just need to be yes or no, is there a better way to
represent that here?

[1]
https://github.com/DMTF/libspdm/pull/2827/files#diff-30c523edca23983e0f16e067772ec18e711a40f53ac49c8dda24301450b724d0R44
[2]
https://www.dmtf.org/sites/default/files/standards/documents/DSP0286_1.0.0WIP90.pdf
> > +
> >  #define SPDM_SOCKET_COMMAND_NORMAL                0x0001
> >  #define SPDM_SOCKET_STORAGE_CMD_IF_SEND           0x0002
> >  #define SPDM_SOCKET_STORAGE_CMD_IF_RECV           0x0003
> > -- 
> > 2.47.1
> > 
> >