xdr_reference.c revision 1.7 
1/*	$OpenBSD: xdr_reference.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
2/*
3 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4 * unrestricted use provided that this legend is included on all tape
5 * media and as a part of the software program in whole or part.  Users
6 * may copy or modify Sun RPC without charge, but are not authorized
7 * to license or distribute it to anyone else except as part of a product or
8 * program developed by the user.
9 *
10 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13 *
14 * Sun RPC is provided with no support and without any obligation on the
15 * part of Sun Microsystems, Inc. to assist in its use, correction,
16 * modification or enhancement.
17 *
18 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20 * OR ANY PART THEREOF.
21 *
22 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23 * or profits or other special, indirect and consequential damages, even if
24 * Sun has been advised of the possibility of such damages.
25 *
26 * Sun Microsystems, Inc.
27 * 2550 Garcia Avenue
28 * Mountain View, California  94043
29 */
30
31/*
32 * xdr_reference.c, Generic XDR routines implementation.
33 *
34 * Copyright (C) 1987, Sun Microsystems, Inc.
35 *
36 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
37 * "pointers".  See xdr.h for more info on the interface to xdr.
38 */
39
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <rpc/types.h>
44#include <rpc/xdr.h>
45
46/*
47 * XDR an indirect pointer
48 * xdr_reference is for recursively translating a structure that is
49 * referenced by a pointer inside the structure that is currently being
50 * translated.  pp references a pointer to storage. If *pp is null
51 * the  necessary storage is allocated.
52 * size is the sizeof the referneced structure.
53 * proc is the routine to handle the referenced structure.
54 */
55bool_t
56xdr_reference(XDR *xdrs,
57    caddr_t *pp,	/* the pointer to work on */
58    u_int size,		/* size of the object pointed to */
59    xdrproc_t proc)	/* xdr routine to handle the object */
60{
61	caddr_t loc = *pp;
62	bool_t stat;
63
64	if (loc == NULL)
65		switch (xdrs->x_op) {
66		case XDR_FREE:
67			return (TRUE);
68
69		case XDR_DECODE:
70			*pp = loc = (caddr_t) mem_alloc(size);
71			if (loc == NULL) {
72				(void) fprintf(stderr,
73				    "xdr_reference: out of memory\n");
74				return (FALSE);
75			}
76			memset(loc, 0, (int)size);
77			break;
78	}
79
80	stat = (*proc)(xdrs, loc);
81
82	if (xdrs->x_op == XDR_FREE) {
83		mem_free(loc, size);
84		*pp = NULL;
85	}
86	return (stat);
87}
88
89
90/*
91 * xdr_pointer():
92 *
93 * XDR a pointer to a possibly recursive data structure. This
94 * differs with xdr_reference in that it can serialize/deserialiaze
95 * trees correctly.
96 *
97 *  What's sent is actually a union:
98 *
99 *  union object_pointer switch (boolean b) {
100 *  case TRUE: object_data data;
101 *  case FALSE: void nothing;
102 *  }
103 *
104 * > objpp: Pointer to the pointer to the object.
105 * > obj_size: size of the object.
106 * > xdr_obj: routine to XDR an object.
107 *
108 */
109bool_t
110xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
111{
112
113	bool_t more_data;
114
115	more_data = (*objpp != NULL);
116	if (! xdr_bool(xdrs,&more_data)) {
117		return (FALSE);
118	}
119	if (! more_data) {
120		*objpp = NULL;
121		return (TRUE);
122	}
123	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
124}
125