Re: [dpdk-dev] [PATCH 2/3] cryptodev: add security operation to crypto operation

["Coyle, David" <david.coyle@intel.com>]

Hi Konstantin,

> > >
> > > >
> > > >  /** Status of crypto operation */ @@ -121,6 +123,13 @@ struct
> > > > rte_crypto_op {
> > > >  		struct rte_crypto_asym_op asym[0];
> > > >  		/**< Asymmetric operation parameters */
> > > >
> > > > +#ifdef RTE_LIBRTE_SECURITY
> > > > +		uint8_t security[0];
> > > > +		/**< Security operation parameters
> > > > +		 * - Must be accessed through a rte_security_op pointer
> > > > +		 */
> > > > +#endif
> > > > +
> > > >  	}; /**< operation specific parameters */  };
> > >
> > > Is there any point to have this extra level of indirection?
> > > Might be simply:
> > >
> > > enum rte_crypto_op_type {
> > > 	....
> > > +	RTE_CRYPTO_OP_TYPE_SEC_DOCSIS,
> > > };
> > > ...
> > > struct rte_crypto_op {
> > > 	....
> > > 	__extension__
> > >         union {
> > >                 struct rte_crypto_sym_op sym[0];
> > >                 /**< Symmetric operation parameters */
> > >
> > >                 struct rte_crypto_asym_op asym[0];
> > >                 /**< Asymmetric operation parameters */
> > >
> > > +	struct rte_security_docsis_op docsis[0];
> > >
> > >         }; /**< operation specific parameters */
> > >
> > > ?
> > [DC] This was to allow some form of extensibility and not to limit this to just
> DOCSIS.
> > If it's felt that having the extra level of indirection is overkill, it can be easily
> changed.
> >
> > However, we cannot include a struct of type 'struct
> > rte_security_docsis_op' (or 'struct rte_security_op') directly here,
> > without creating nasty circular dependency of includes between
> rte_cryptodev and rte_security.
> >
> > I had tried defining an opaque version 'struct rte_security_op' (i.e.
> > no fields within the struct) here in rte_crypto.h, but the compiler
> > complained that it couldn't determine the size of the struct, even though
> it's a zero length array.
> >
> > That is why I had to use the uint8_t in 'uint8_t security[0];' - I
> > don't like this, but I couldn't find another way that kept the compiler happy
> and didn't create a circular dependency.
> 
> I see... would it be an option to name this struct 'struct rte_sym_docsis_op
> and and move actual definition inside
> lib/librte_cryptodev/rte_crypto_sym.h?
> 
[DC] It's certainly an option and would work but I don't think it's a good idea to be putting
protocol specific structs like this in rte_cryptodev - that's what rte_security is for.
Do you think it would be ok to do this?

I'd be interested to hear what cryptodev/security maintainers and others think too.
Akhil/Declan - any thoughts on best approach here?
>