xdr.h

/*	$NetBSD: xdr.h,v 1.19 2000/07/17 05:00:45 matt Exp $	*/

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice, 
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, 
 *   this list of conditions and the following disclaimer in the documentation 
 *   and/or other materials provided with the distribution.
 * - Neither the name of Sun Microsystems, Inc. nor the names of its 
 *   contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */

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

#ifndef _KRPC_XDR_H
#define _KRPC_XDR_H
#include <sys/cdefs.h>

struct mbuf;

/*
 * 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)

/*
 * 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 XDR {
	enum xdr_op	x_op;		/* operation; fast additional param */
	const struct xdr_ops {
		/* get a long from underlying stream */
		bool_t	(*x_getlong)(struct XDR *, long *);
		/* put a long to " */
		bool_t	(*x_putlong)(struct XDR *, const long *);
		/* get some bytes from " */
		bool_t	(*x_getbytes)(struct XDR *, char *, u_int);
		/* put some bytes to " */
		bool_t	(*x_putbytes)(struct XDR *, const char *, u_int);
		/* put mbuf or copy its bytes */
		bool_t	(*x_putmbuf)(struct XDR *, struct mbuf *);
		/* returns bytes off from beginning */
		u_int	(*x_getpostn)(struct XDR *);
		/* lets you reposition the stream */
		bool_t  (*x_setpostn)(struct XDR *, u_int);
		/* buf quick ptr to buffered data */
		int32_t *(*x_inline)(struct XDR *, u_int);
		/* free privates of this xdr_stream */
		void	(*x_destroy)(struct XDR *);
		bool_t	(*x_control)(struct XDR *, int, void *);
	} *x_ops;
	char *	 	x_public;	/* users' data */
	void *		x_private;	/* pointer to private data */
	char * 		x_base;		/* private used for position info */
	u_int		x_handy;	/* extra private word */
} XDR;

/*
 * 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.
 */
#ifdef _KERNEL
typedef	bool_t (*xdrproc_t)(XDR *, void *, ...);
#else
/*
 * XXX can't actually prototype it, because some take three args!!!
 */
typedef	bool_t (*xdrproc_t)(XDR *, ...);
#endif

/*
 * Operations defined on a XDR handle
 *
 * XDR		*xdrs;
 * long		*longp;
 * char *	 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)

static __inline int
xdr_getint32(XDR *xdrs, int32_t *ip)
{
	long l;

	if (!xdr_getlong(xdrs, &l))
		return (FALSE);
	*ip = (int32_t)l;
	return (TRUE);
}

static __inline int
xdr_putint32(XDR *xdrs, int32_t *ip)
{
	long l;

	l = (long)*ip;
	return xdr_putlong(xdrs, &l);
}

#define XDR_GETINT32(xdrs, int32p)	xdr_getint32(xdrs, int32p)
#define XDR_PUTINT32(xdrs, int32p)	xdr_putint32(xdrs, int32p)

#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_PUTMBUF(xdrs, mbuf)				\
	(*(xdrs)->x_ops->x_putmbuf)(xdrs, mbuf)
#define xdr_putmbuf(xdrs, mbuf)				\
	(*(xdrs)->x_ops->x_putmbuf)(xdrs, mbuf)

#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)

#define XDR_CONTROL(xdrs, req, op)			\
	(((xdrs)->x_ops->x_control == NULL) ? (FALSE) :	\
		(*(xdrs)->x_ops->x_control)(xdrs, req, op))
#define xdr_control(xdrs, req, op) XDR_CONTROL(xdrs, req, op)

/*
 * Solaris strips the '_t' from these types -- not sure why.
 * But, let's be compatible.
 */
#define xdr_rpcvers(xdrs, versp) xdr_uint32_t(xdrs, versp)
#define xdr_rpcprog(xdrs, progp) xdr_uint32_t(xdrs, progp)
#define xdr_rpcproc(xdrs, procp) xdr_uint32_t(xdrs, procp)
#define xdr_rpcprot(xdrs, protp) xdr_uint32_t(xdrs, protp)
#define xdr_rpcport(xdrs, portp) xdr_uint32_t(xdrs, portp)

/*
 * Support struct for discriminated unions.
 * You create an array of xdrdiscrim structures, terminated with
 * an 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;
	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_INT32(buf)		((int32_t)__ntohl((uint32_t)*(buf)++))
#define IXDR_PUT_INT32(buf, v)		(*(buf)++ =(int32_t)__htonl((uint32_t)v))
#define IXDR_GET_U_INT32(buf)		((uint32_t)IXDR_GET_INT32(buf))
#define IXDR_PUT_U_INT32(buf, v)	IXDR_PUT_INT32((buf), ((int32_t)(v)))

#define IXDR_GET_UINT32(buf)		((uint32_t)IXDR_GET_INT32(buf))
#define IXDR_PUT_UINT32(buf, v)		IXDR_PUT_INT32((buf), ((int32_t)(v)))

#define IXDR_GET_LONG(buf)		((long)__ntohl((uint32_t)*(buf)++))
#define IXDR_PUT_LONG(buf, v)		(*(buf)++ =(int32_t)__htonl((uint32_t)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), (v))
#define IXDR_PUT_ENUM(buf, v)		IXDR_PUT_LONG((buf), (v))
#define IXDR_PUT_U_LONG(buf, v)		IXDR_PUT_LONG((buf), (v))
#define IXDR_PUT_SHORT(buf, v)		IXDR_PUT_LONG((buf), (v))
#define IXDR_PUT_U_SHORT(buf, v)	IXDR_PUT_LONG((buf), (v))

/*
 * These are the "generic" xdr routines.
 */
__BEGIN_DECLS
extern bool_t	xdr_void(XDR *, void *);
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_int16_t(XDR *, int16_t *);
extern bool_t	xdr_uint16_t(XDR *, uint16_t *);
extern bool_t	xdr_int32_t(XDR *, int32_t *);
extern bool_t	xdr_uint32_t(XDR *, uint32_t *);
extern bool_t	xdr_int64_t(XDR *, int64_t *);
extern bool_t	xdr_uint64_t(XDR *, uint64_t *);
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 *, char *, u_int);
extern bool_t	xdr_string(XDR *, char **, u_int);
extern bool_t	xdr_union(XDR *, enum_t *, char *, const struct xdr_discrim *, xdrproc_t);
extern bool_t	xdr_char(XDR *, char *);
extern bool_t	xdr_u_char(XDR *, u_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_quadruple(XDR *, long double *);
extern bool_t	xdr_reference(XDR *, char **, u_int, xdrproc_t);
extern bool_t	xdr_pointer(XDR *, char **, u_int, xdrproc_t);
extern bool_t	xdr_wrapstring(XDR *, char **);
extern void	xdr_free(xdrproc_t, void *);
extern bool_t	xdr_hyper(XDR *, quad_t *);
extern bool_t	xdr_u_hyper(XDR *, u_quad_t *);
extern bool_t	xdr_longlong_t(XDR *, quad_t *);
extern bool_t	xdr_u_longlong_t(XDR *, u_quad_t *);
extern unsigned long xdr_sizeof(xdrproc_t func, void *data);
__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;
extern bool_t   xdr_netobj(XDR *, struct netobj *);

/*
 * These are XDR control operators
 */

#define	XDR_GET_BYTES_AVAIL 	1
#define	XDR_PEEK		2
#define	XDR_SKIPBYTES		3

struct xdr_bytesrec {
	bool_t xc_is_last_record;
	size_t xc_num_avail;
};

typedef struct xdr_bytesrec xdr_bytesrec;


/*
 * These are the public routines for the various implementations of
 * xdr streams.
 */
__BEGIN_DECLS
/* XDR using memory buffers */
extern void   xdrmem_create(XDR *, char *, u_int, enum xdr_op);

/* XDR using mbufs */
extern void   xdrmbuf_create(XDR *, struct mbuf *, enum xdr_op);
extern struct mbuf * xdrmbuf_getall(XDR *);

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

#endif /* !_KRPC_XDR_H */