/*	$OpenBSD: xdr_array.c,v 1.10 2010/09/01 14:43:34 millert Exp $ */

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * 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 the "Oracle America, 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
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 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * xdr_array.c, Generic XDR routines implementation.
 *
 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
 * arrays.  See xdr.h for more info on the interface to xdr.
 */



#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <rpc/types.h>
#include <rpc/xdr.h>

/*
 * XDR an array of arbitrary elements
 * *addrp is a pointer to the array, *sizep is the number of elements.
 * If addrp is NULL (*sizep * elsize) bytes are allocated.
 * elsize is the size (in bytes) of each element, and elproc is the
 * xdr procedure to call to handle each element of the array.
 */
bool_t
xdr_array(XDR *xdrs,
    caddr_t *addrp,	/* array pointer */
    u_int *sizep,	/* number of elements */
    u_int maxsize,	/* max numberof elements */
    u_int elsize,	/* size in bytes of each element */
    xdrproc_t elproc)	/* xdr routine to handle each element */
{
	caddr_t target = *addrp;
	u_int nodesize, c, i;
	bool_t stat = TRUE;

	/* like strings, arrays are really counted arrays */
	if (!xdr_u_int(xdrs, sizep))
		return (FALSE);

	c = *sizep;
	if ((c > maxsize || c > UINT_MAX/elsize) &&
	    xdrs->x_op != XDR_FREE)
		return (FALSE);
	nodesize = c * elsize;

	/*
	 * if we are deserializing, we may need to allocate an array.
	 * We also save time by checking for a null array if we are freeing.
	 */
	if (target == NULL) {
		switch (xdrs->x_op) {
		case XDR_DECODE:
			if (c == 0)
				return (TRUE);
			*addrp = target = mem_alloc(nodesize);
			if (target == NULL) {
				(void) fprintf(stderr, 
				    "xdr_array: out of memory\n");
				return (FALSE);
			}
			memset(target, 0, nodesize);
			break;
		case XDR_FREE:
			return (TRUE);
		}
	}
	
	/*
	 * now we xdr each element of array
	 */
	for (i = 0; (i < c) && stat; i++) {
		stat = (*elproc)(xdrs, target);
		target += elsize;
	}

	/*
	 * the array may need freeing
	 */
	if (xdrs->x_op == XDR_FREE) {
		mem_free(*addrp, nodesize);
		*addrp = NULL;
	}
	return (stat);
}

/*
 * xdr_vector():
 *
 * XDR a fixed length array. Unlike variable-length arrays,
 * the storage of fixed length arrays is static and unfreeable.
 * > basep: base of the array
 * > size: size of the array
 * > elemsize: size of each element
 * > xdr_elem: routine to XDR each element
 */
bool_t
xdr_vector(XDR *xdrs, char *basep, u_int nelem, u_int elemsize,
    xdrproc_t xdr_elem)
{
	char *elptr;
	u_int i;

	elptr = basep;
	for (i = 0; i < nelem; i++) {
		if (!(*xdr_elem)(xdrs, elptr))
			return(FALSE);
		elptr += elemsize;
	}
	return(TRUE);	
}