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      1 /*	$NetBSD: xdr_reference.c,v 1.19 2022/02/13 22:20:08 andvar Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2010, Oracle America, Inc.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions are
      8  * met:
      9  *
     10  *     * Redistributions of source code must retain the above copyright
     11  *       notice, this list of conditions and the following disclaimer.
     12  *     * Redistributions in binary form must reproduce the above
     13  *       copyright notice, this list of conditions and the following
     14  *       disclaimer in the documentation and/or other materials
     15  *       provided with the distribution.
     16  *     * Neither the name of the "Oracle America, Inc." nor the names of its
     17  *       contributors may be used to endorse or promote products derived
     18  *       from this software without specific prior written permission.
     19  *
     20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 #if defined(LIBC_SCCS) && !defined(lint)
     36 #if 0
     37 static char *sccsid = "@(#)xdr_reference.c 1.11 87/08/11 SMI";
     38 static char *sccsid = "@(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC";
     39 #else
     40 __RCSID("$NetBSD: xdr_reference.c,v 1.19 2022/02/13 22:20:08 andvar Exp $");
     41 #endif
     42 #endif
     43 
     44 /*
     45  * xdr_reference.c, Generic XDR routines implementation.
     46  *
     47  * Copyright (C) 1987, Sun Microsystems, Inc.
     48  *
     49  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
     50  * "pointers".  See xdr.h for more info on the interface to xdr.
     51  */
     52 
     53 #include "namespace.h"
     54 
     55 #include <err.h>
     56 #include <stdio.h>
     57 #include <stdlib.h>
     58 #include <string.h>
     59 
     60 #include <rpc/types.h>
     61 #include <rpc/xdr.h>
     62 
     63 #ifdef __weak_alias
     64 __weak_alias(xdr_pointer,_xdr_pointer)
     65 __weak_alias(xdr_reference,_xdr_reference)
     66 #endif
     67 
     68 /*
     69  * XDR an indirect pointer
     70  * xdr_reference is for recursively translating a structure that is
     71  * referenced by a pointer inside the structure that is currently being
     72  * translated.  pp references a pointer to storage. If *pp is null
     73  * the  necessary storage is allocated.
     74  * size is the sizeof the referenced structure.
     75  * proc is the routine to handle the referenced structure.
     76  */
     77 bool_t
     78 xdr_reference(XDR *xdrs, caddr_t *pp, u_int size, xdrproc_t proc)
     79 {
     80 	caddr_t loc = *pp;
     81 	bool_t stat;
     82 
     83 	if (loc == NULL)
     84 		switch (xdrs->x_op) {
     85 		case XDR_FREE:
     86 			return (TRUE);
     87 
     88 		case XDR_DECODE:
     89 			*pp = loc = mem_alloc(size);
     90 			if (loc == NULL) {
     91 				warn("%s: out of memory", __func__);
     92 				return (FALSE);
     93 			}
     94 			memset(loc, 0, size);
     95 			break;
     96 
     97 		case XDR_ENCODE:
     98 			break;
     99 		}
    100 
    101 	stat = (*proc)(xdrs, loc);
    102 
    103 	if (xdrs->x_op == XDR_FREE) {
    104 		mem_free(loc, size);
    105 		*pp = NULL;
    106 	}
    107 	return (stat);
    108 }
    109 
    110 
    111 /*
    112  * xdr_pointer():
    113  *
    114  * XDR a pointer to a possibly recursive data structure. This
    115  * differs with xdr_reference in that it can serialize/deserialize
    116  * trees correctly.
    117  *
    118  *  What's sent is actually a union:
    119  *
    120  *  union object_pointer switch (boolean b) {
    121  *  case TRUE: object_data data;
    122  *  case FALSE: void nothing;
    123  *  }
    124  *
    125  * > objpp: Pointer to the pointer to the object.
    126  * > obj_size: size of the object.
    127  * > xdr_obj: routine to XDR an object.
    128  *
    129  */
    130 bool_t
    131 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
    132 {
    133 
    134 	bool_t more_data;
    135 
    136 	more_data = (*objpp != NULL);
    137 	if (! xdr_bool(xdrs,&more_data)) {
    138 		return (FALSE);
    139 	}
    140 	if (! more_data) {
    141 		*objpp = NULL;
    142 		return (TRUE);
    143 	}
    144 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
    145 }
    146