Full Generic System V ABI

** Reply to an RPC request that was rejected by the server:* The request can be rejected for two reasons: either the* server is not running a compatible version of the RPC* protocol (R P C _ M I S M A T C H), or the server refuses to* authenticate the caller (A U T H _ E R R O R). In case of an RPC* version mismatch, the server returns the lowest and highest* supported RPC version numbers. In case of refused* authentication, failure status is returned.*/u n i o n r e j e c t e d _ r e p l y s w i t c h ( r e j e c t _ s t a t s t a t ) {c a s e R P C _ M I S M A T C H :s t r u c t {u n s i g n e d i n t l o w ;u n s i g n e d i n t h i g h ;} m i s m a t c h _ i n f o ;c a s e A U T H _ E R R O R :a u t h _ s t a t s t a t ;} ;Authentication ProtocolsAs previously stated, authentication parameters are opaque, but open-ended tothe rest of the RPC protocol. This section defines some ‘‘flavors’’ of authenticationwhich are already implemented. Other sites are free to invent new authenticationtypes, with the same rules of flavor number assignment as there is for programnumber assignment.Null AuthenticationOften calls must be made where the caller does not know who he is or the serverdoes not care who the caller is. In this case, the flavor value (the discriminant ofthe o p a q u e _ a u t h’s union) of the RPC message’s credentials, verifier, and responseverifier is A U T H _ N U L L. The bytes of the opaque_auth’s body are undefined. It isrecommended that the opaque length be zero.Basic Authentication for UNIX SystemsThe callers of a remote procedure may wish to identify themselves as they areidentified on a UNIX system. The value of the credential’s discriminant of an RPCcall message is A U T H _ S Y S. The bytes of the credential’s opaque body encode thefollowing structure:⎜7-30 FORMATS AND PROTOCOLS