xdr_reference.c revision 1.3 
1/*
2 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3 * unrestricted use provided that this legend is included on all tape
4 * media and as a part of the software program in whole or part.  Users
5 * may copy or modify Sun RPC without charge, but are not authorized
6 * to license or distribute it to anyone else except as part of a product or
7 * program developed by the user.
8 *
9 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12 *
13 * Sun RPC is provided with no support and without any obligation on the
14 * part of Sun Microsystems, Inc. to assist in its use, correction,
15 * modification or enhancement.
16 *
17 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19 * OR ANY PART THEREOF.
20 *
21 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22 * or profits or other special, indirect and consequential damages, even if
23 * Sun has been advised of the possibility of such damages.
24 *
25 * Sun Microsystems, Inc.
26 * 2550 Garcia Avenue
27 * Mountain View, California  94043
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char *rcsid = "$OpenBSD: xdr_reference.c,v 1.3 1996/08/19 08:32:06 tholo Exp $";
32#endif /* LIBC_SCCS and not lint */
33
34/*
35 * xdr_reference.c, Generic XDR routines impelmentation.
36 *
37 * Copyright (C) 1987, Sun Microsystems, Inc.
38 *
39 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
40 * "pointers".  See xdr.h for more info on the interface to xdr.
41 */
42
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
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(xdrs, pp, size, proc)
60	register XDR *xdrs;
61	caddr_t *pp;		/* the pointer to work on */
62	u_int size;		/* size of the object pointed to */
63	xdrproc_t proc;		/* xdr routine to handle the object */
64{
65	register caddr_t loc = *pp;
66	register bool_t stat;
67
68	if (loc == NULL)
69		switch (xdrs->x_op) {
70		case XDR_FREE:
71			return (TRUE);
72
73		case XDR_DECODE:
74			*pp = loc = (caddr_t) mem_alloc(size);
75			if (loc == NULL) {
76				(void) fprintf(stderr,
77				    "xdr_reference: out of memory\n");
78				return (FALSE);
79			}
80			memset(loc, 0, (int)size);
81			break;
82	}
83
84	stat = (*proc)(xdrs, loc);
85
86	if (xdrs->x_op == XDR_FREE) {
87		mem_free(loc, size);
88		*pp = NULL;
89	}
90	return (stat);
91}
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(xdrs,objpp,obj_size,xdr_obj)
115	register XDR *xdrs;
116	char **objpp;
117	u_int obj_size;
118	xdrproc_t xdr_obj;
119{
120
121	bool_t more_data;
122
123	more_data = (*objpp != NULL);
124	if (! xdr_bool(xdrs,&more_data)) {
125		return (FALSE);
126	}
127	if (! more_data) {
128		*objpp = NULL;
129		return (TRUE);
130	}
131	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
132}
133