xdr.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* xdr.h, External Data Representation Serialization Routines.
*
* Copyright (C) 1984, Sun Microsystems, Inc.
*/
#ifndef _rpc_xdr_h
#define _rpc_xdr_h
/*
* XDR provides a conventional way for converting between C data
* types and an external bit-string representation. Library supplied
* routines provide for the conversion on built-in C data types. These
* routines and utility routines defined here are used to help implement
*
* Each data type provides a single procedure which takes two arguments:
*
* bool_t
* xdrproc(xdrs, argresp)
* XDR *xdrs;
* <type> *argresp;
*
* xdrs is an instance of a XDR handle, to which or from which the data
* type is to be converted. argresp is a pointer to the structure to be
* converted. The XDR handle contains an operation field which indicates
* which of the operations (ENCODE, DECODE * or FREE) is to be performed.
*
* XDR_DECODE may allocate space if the pointer argresp is null. This
* data can be freed with the XDR_FREE operation.
*
* We write only one procedure per data type to make it easy
* to keep the encode and decode procedures for a data type consistent.
* In many cases the same code performs all operations on a user defined type,
* because all the hard work is done in the component type routines.
* decode as a series of calls on the nested data types.
*/
/*
* Xdr operations. XDR_ENCODE causes the type to be encoded into the
* stream. XDR_DECODE causes the type to be extracted from the stream.
* XDR_FREE can be used to release the space allocated by an XDR_DECODE
* request.
*/
enum xdr_op {
XDR_ENCODE=0,
XDR_DECODE=1,
XDR_FREE=2
};
/*
* This is the number of bytes per unit of external data.
*/
#define BYTES_PER_XDR_UNIT (4)
/*
* A xdrproc_t exists for each data type which is to be encoded or decoded.
*
* The second argument to the xdrproc_t is a pointer to an opaque pointer.
* The opaque pointer generally points to a structure of the data type
* to be decoded. If this pointer is 0, then the type routines should
* allocate dynamic storage of the appropriate size and return it.
* bool_t (*xdrproc_t)(XDR *, caddr_t *);
*/
/*
* The XDR handle.
* Contains operation which is being applied to the stream,
* an operations vector for the paticular implementation (e.g. see xdr_mem.c),
* and two private fields for the use of the particular impelementation.
*/
typedef struct {
struct xdr_ops {
long * (*x_inline)(); /* buf quick ptr to buffered data */
void (*x_destroy)(); /* free privates of this xdr_stream */
} *x_ops;
int x_handy; /* extra private word */
} XDR;
/*
* Operations defined on a XDR handle
*
* XDR *xdrs;
* long *longp;
* caddr_t addr;
* u_int len;
* u_int pos;
*/
#define XDR_GETPOS(xdrs) \
#define xdr_getpos(xdrs) \
#define XDR_DESTROY(xdrs) \
/*
* Support struct for discriminated unions.
* You create an array of xdrdiscrim structures, terminated with
* a entry with a null procedure pointer. The xdr_union routine gets
* the discriminant value and then searches the array of structures
* for a matching value. If a match is found the associated xdr routine
* is called to handle that part of the union. If there is
* no match, then a default routine may be called.
* If there is no match and no default routine it is an error.
*/
#define NULL_xdrproc_t ((xdrproc_t)0)
struct xdr_discrim {
int value;
};
/*
* Caveat emptor: these use single memory cycles to get the
* data from the underlying buffer, and will fail to operate
* properly if the data is not aligned. The standard way to use these
* is to say:
* if ((buf = XDR_INLINE(xdrs, count)) == NULL)
* return (FALSE);
* <<< macro calls >>>
* where ``count'' is the number of bytes of data occupied
* by the primitive data types.
*
* N.B. and frozen for all time: each data type here uses 4 bytes
* of external representation.
*/
/*
* These are the "generic" xdr routines.
*/
extern bool_t xdr_u_long();
extern bool_t xdr_u_short();
extern bool_t xdr_opaque();
extern bool_t xdr_string();
#ifndef KERNEL
extern void xdr_free();
extern bool_t xdr_u_char();
extern bool_t xdr_vector();
extern bool_t xdr_double();
extern bool_t xdr_reference();
extern bool_t xdr_pointer();
extern bool_t xdr_wrapstring();
#endif !KERNEL
/*
* Common opaque bytes objects used by many rpc protocols;
* declared here due to commonality.
*/
#define MAX_NETOBJ_SZ 1024
struct netobj {
char *n_bytes;
};
extern bool_t xdr_netobj();
/*
* These are the public routines for the various implementations of
* xdr streams.
*/
extern void xdrmem_create(); /* XDR using memory buffers */
#ifndef KERNEL
extern void xdrstdio_create(); /* XDR using stdio library */
extern void xdrrec_create(); /* XDR pseudo records for tcp */
extern int xdrrec_readbytes(); /* like a read on a pipe */
#else
extern void xdrmbuf_init(); /* XDR using kernel mbufs */
#endif !KERNEL
#endif /*!_rpc_xdr_h*/