1/*	$NetBSD: xdr_reference.c,v 1.13 2000/01/22 22:19:18 mycroft Exp	$ */
2
3/*
4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5 * unrestricted use provided that this legend is included on all tape
6 * media and as a part of the software program in whole or part.  Users
7 * may copy or modify Sun RPC without charge, but are not authorized
8 * to license or distribute it to anyone else except as part of a product or
9 * program developed by the user.
10 *
11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14 *
15 * Sun RPC is provided with no support and without any obligation on the
16 * part of Sun Microsystems, Inc. to assist in its use, correction,
17 * modification or enhancement.
18 *
19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21 * OR ANY PART THEREOF.
22 *
23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24 * or profits or other special, indirect and consequential damages, even if
25 * Sun has been advised of the possibility of such damages.
26 *
27 * Sun Microsystems, Inc.
28 * 2550 Garcia Avenue
29 * Mountain View, California  94043
30 */
31
32#include <sys/cdefs.h>
33/*
34 * xdr_reference.c, Generic XDR routines implementation.
35 *
36 * Copyright (C) 1987, Sun Microsystems, Inc.
37 *
38 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
39 * "pointers".  See xdr.h for more info on the interface to xdr.
40 */
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/malloc.h>
45
46#include <rpc/types.h>
47#include <rpc/xdr.h>
48
49/*
50 * XDR an indirect pointer
51 * xdr_reference is for recursively translating a structure that is
52 * referenced by a pointer inside the structure that is currently being
53 * translated.  pp references a pointer to storage. If *pp is null
54 * the  necessary storage is allocated.
55 * size is the sizeof the referneced structure.
56 * proc is the routine to handle the referenced structure.
57 */
58bool_t
59xdr_reference(XDR *xdrs,
60    caddr_t *pp,		/* the pointer to work on */
61    u_int size,			/* size of the object pointed to */
62    xdrproc_t proc)		/* xdr routine to handle the object */
63{
64	caddr_t loc = *pp;
65	bool_t stat;
66
67	if (loc == NULL)
68		switch (xdrs->x_op) {
69		case XDR_FREE:
70			return (TRUE);
71
72		case XDR_DECODE:
73			*pp = loc = (caddr_t) mem_alloc(size);
74			if (loc == NULL) {
75				printf("xdr_reference: out of memory");
76				return (FALSE);
77			}
78			memset(loc, 0, size);
79			break;
80
81		case XDR_ENCODE:
82			break;
83		}
84
85	stat = (*proc)(xdrs, loc);
86
87	if (xdrs->x_op == XDR_FREE) {
88		mem_free(loc, size);
89		*pp = NULL;
90	}
91	return (stat);
92}
93
94/*
95 * xdr_pointer():
96 *
97 * XDR a pointer to a possibly recursive data structure. This
98 * differs with xdr_reference in that it can serialize/deserialiaze
99 * trees correctly.
100 *
101 *  What's sent is actually a union:
102 *
103 *  union object_pointer switch (boolean b) {
104 *  case TRUE: object_data data;
105 *  case FALSE: void nothing;
106 *  }
107 *
108 * > objpp: Pointer to the pointer to the object.
109 * > obj_size: size of the object.
110 * > xdr_obj: routine to XDR an object.
111 *
112 */
113bool_t
114xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
115{
116
117	bool_t more_data;
118
119	more_data = (*objpp != NULL);
120	if (! xdr_bool(xdrs,&more_data)) {
121		return (FALSE);
122	}
123	if (! more_data) {
124		*objpp = NULL;
125		return (TRUE);
126	}
127	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
128}
129