/*!\file rpc/xdr.h
 * eXternal Data Representation.
 */

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 *
 *	from: @(#)xdr.h 1.19 87/04/22 SMI
 *	from: @(#)xdr.h	2.2 88/07/29 4.0 RPCSRC
 *	$Id: xdr.h,v 1.4 1996/01/30 23:32:45 mpp Exp $
 */

/*
 * xdr.h, External Data Representation Serialization Routines.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */

#ifndef __RPC_XDR_H
#define __RPC_XDR_H

#ifndef __SYS_CDEFS_H
#include <sys/cdefs.h>
#endif

/*
 * 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
 * a type encode/decode routine for each user-defined type.
 *
 * 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)
#define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) / BYTES_PER_XDR_UNIT) \
		    * BYTES_PER_XDR_UNIT)

/*
 * 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 *);
 */
typedef	bool_t (*xdrproc_t)();

/*
 * The XDR handle.
 * Contains operation which is being applied to the stream,
 * an operations vector for the particular implementation (e.g. see xdr_mem.c),
 * and two private fields for the use of the particular implementation.
 */
typedef struct {
	enum xdr_op	x_op;		/* operation; fast additional param */
	struct xdr_ops {
		bool_t	(*x_getlong)();	/* get a long from underlying stream */
		bool_t	(*x_putlong)();	/* put a long to " */
		bool_t	(*x_getbytes)();/* get some bytes from " */
		bool_t	(*x_putbytes)();/* put some bytes to " */
		u_int	(*x_getpostn)();/* returns bytes off from beginning */
		bool_t  (*x_setpostn)();/* lets you reposition the stream */
		long *	(*x_inline)();	/* buf quick ptr to buffered data */
		void	(*x_destroy)();	/* free privates of this xdr_stream */
	} *x_ops;
	caddr_t 	x_public;	/* users' data */
	caddr_t		x_private;	/* pointer to private data */
	caddr_t 	x_base;		/* private used for position info */
	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_GETLONG(xdrs, longp)			\
	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)
#define xdr_getlong(xdrs, longp)			\
	(*(xdrs)->x_ops->x_getlong)(xdrs, longp)

#define XDR_PUTLONG(xdrs, longp)			\
	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)
#define xdr_putlong(xdrs, longp)			\
	(*(xdrs)->x_ops->x_putlong)(xdrs, longp)

#define XDR_GETBYTES(xdrs, addr, len)			\
	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)
#define xdr_getbytes(xdrs, addr, len)			\
	(*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)

#define XDR_PUTBYTES(xdrs, addr, len)			\
	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)
#define xdr_putbytes(xdrs, addr, len)			\
	(*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)

#define XDR_GETPOS(xdrs)				\
	(*(xdrs)->x_ops->x_getpostn)(xdrs)
#define xdr_getpos(xdrs)				\
	(*(xdrs)->x_ops->x_getpostn)(xdrs)

#define XDR_SETPOS(xdrs, pos)				\
	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)
#define xdr_setpos(xdrs, pos)				\
	(*(xdrs)->x_ops->x_setpostn)(xdrs, pos)

#define	XDR_INLINE(xdrs, len)				\
	(*(xdrs)->x_ops->x_inline)(xdrs, len)
#define	xdr_inline(xdrs, len)				\
	(*(xdrs)->x_ops->x_inline)(xdrs, len)

#define	XDR_DESTROY(xdrs)				\
	if ((xdrs)->x_ops->x_destroy) 			\
		(*(xdrs)->x_ops->x_destroy)(xdrs)
#define	xdr_destroy(xdrs)				\
	if ((xdrs)->x_ops->x_destroy) 			\
		(*(xdrs)->x_ops->x_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)0L)
struct xdr_discrim {
	int	value;
	xdrproc_t proc;
};

/*
 * In-line routines for fast encode/decode of primitive data types.
 * 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.
 */
#define IXDR_GET_LONG(buf)         ((long)ntohl((u_long)*(buf)++))
#define IXDR_PUT_LONG(buf, v)      (*(buf)++ = (long)htonl((u_long)v))

#define IXDR_GET_BOOL(buf)         ((bool_t)IXDR_GET_LONG(buf))
#define IXDR_GET_ENUM(buf, t)      ((t)IXDR_GET_LONG(buf))
#define IXDR_GET_U_LONG(buf)       ((u_long)IXDR_GET_LONG(buf))
#define IXDR_GET_SHORT(buf)        ((short)IXDR_GET_LONG(buf))
#define IXDR_GET_U_SHORT(buf)      ((u_short)IXDR_GET_LONG(buf))

#define IXDR_PUT_BOOL(buf, v)      IXDR_PUT_LONG((buf), ((long)(v)))
#define IXDR_PUT_ENUM(buf, v)      IXDR_PUT_LONG((buf), ((long)(v)))
#define IXDR_PUT_U_LONG(buf, v)    IXDR_PUT_LONG((buf), ((long)(v)))
#define IXDR_PUT_SHORT(buf, v)     IXDR_PUT_LONG((buf), ((long)(v)))
#define IXDR_PUT_U_SHORT(buf, v)   IXDR_PUT_LONG((buf), ((long)(v)))

/*
 * These are the "generic" xdr routines.
 */

__BEGIN_DECLS

extern bool_t   xdr_void       (XDR *, caddr_t);
extern bool_t   xdr_int        (XDR *, int *);
extern bool_t   xdr_u_int      (XDR *, u_int *);
extern bool_t   xdr_long       (XDR *, long *);
extern bool_t   xdr_u_long     (XDR *, u_long *);
extern bool_t   xdr_short      (XDR *, short *);
extern bool_t   xdr_u_short    (XDR *, u_short *);
extern bool_t   xdr_bool       (XDR *, bool_t *);
extern bool_t   xdr_enum       (XDR *, enum_t *);
extern bool_t   xdr_array      (XDR *, char **, u_int *, u_int, u_int, xdrproc_t);
extern bool_t   xdr_bytes      (XDR *, char **, u_int *, u_int);
extern bool_t __xdr_opaque     (XDR *, caddr_t, u_int);
extern bool_t   xdr_string     (XDR *, char **, u_int);
extern bool_t   xdr_union      (XDR *, enum_t *, char *, struct xdr_discrim *, xdrproc_t);
extern bool_t   xdr_char       (XDR *, char *);
extern bool_t   xdr_u_char     (XDR *, char *);
extern bool_t   xdr_vector     (XDR *, char *, u_int, u_int, xdrproc_t);
extern bool_t   xdr_float      (XDR *, float *);
extern bool_t   xdr_double     (XDR *, double *);
extern bool_t   xdr_reference  (XDR *, caddr_t *, u_int, xdrproc_t);
extern bool_t   xdr_pointer    (XDR *, caddr_t *, u_int, xdrproc_t);
extern bool_t   xdr_wrapstring (XDR *, char **);
extern void     xdr_free       (xdrproc_t, char *);

/*
 * Hack to avoid missing typecast from rpcgen when
 * producing xdr_opaque()
 */
#define xdr_opaque(xdr,obj,size) __xdr_opaque(xdr,(caddr_t)obj,size) 

__END_DECLS

/*
 * Common opaque bytes objects used by many rpc protocols;
 * declared here due to commonality.
 */
#define MAX_NETOBJ_SZ 1024
struct netobj {
	u_int	n_len;
	char	*n_bytes;
};
typedef struct netobj netobj;

/*
 * These are the public routines for the various implementations of
 * xdr streams.
 */

__BEGIN_DECLS

extern bool_t xdr_netobj (XDR *, struct netobj *);

/* XDR using memory buffers */
extern void xdrmem_create (XDR *, char *, u_int, enum xdr_op);

#if defined(__STDIO_H) || defined(_STDIO_H) || defined(__dj_include_stdio_h_)
/* XDR using stdio library */
extern void xdrstdio_create (XDR *, FILE *, enum xdr_op);
#endif

/* XDR pseudo records for tcp */
extern void xdrrec_create (XDR *, u_int, u_int, char *, int (*)(), int (*)());

/* make end of xdr record */
extern bool_t xdrrec_endofrecord (XDR *, int);

/* move to beginning of next record */
extern bool_t xdrrec_skiprecord (XDR *);

/* true if no more input */
extern bool_t xdrrec_eof (XDR *);

__END_DECLS

#endif
