xdr_reference.c revision 11669 
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)
31/*static char *sccsid = "from: @(#)xdr_reference.c 1.11 87/08/11 SMI";*/
32/*static char *sccsid = "from: @(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC";*/
33static char *rcsid = "$Id: xdr_reference.c,v 1.2 1995/05/30 05:42:12 rgrimes Exp $";
34#endif
35
36/*
37 * xdr_reference.c, Generic XDR routines impelmentation.
38 *
39 * Copyright (C) 1987, Sun Microsystems, Inc.
40 *
41 * These are the "non-trivial" xdr primitives used to serialize and de-serialize
42 * "pointers".  See xdr.h for more info on the interface to xdr.
43 */
44
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <rpc/types.h>
49#include <rpc/xdr.h>
50
51#define LASTUNSIGNED	((u_int)0-1)
52
53/*
54 * XDR an indirect pointer
55 * xdr_reference is for recursively translating a structure that is
56 * referenced by a pointer inside the structure that is currently being
57 * translated.  pp references a pointer to storage. If *pp is null
58 * the  necessary storage is allocated.
59 * size is the sizeof the referneced structure.
60 * proc is the routine to handle the referenced structure.
61 */
62bool_t
63xdr_reference(xdrs, pp, size, proc)
64	register XDR *xdrs;
65	caddr_t *pp;		/* the pointer to work on */
66	u_int size;		/* size of the object pointed to */
67	xdrproc_t proc;		/* xdr routine to handle the object */
68{
69	register caddr_t loc = *pp;
70	register bool_t stat;
71
72	if (loc == NULL)
73		switch (xdrs->x_op) {
74		case XDR_FREE:
75			return (TRUE);
76
77		case XDR_DECODE:
78			*pp = loc = (caddr_t) mem_alloc(size);
79			if (loc == NULL) {
80				(void) fprintf(stderr,
81				    "xdr_reference: out of memory\n");
82				return (FALSE);
83			}
84			bzero(loc, (int)size);
85			break;
86	}
87
88	stat = (*proc)(xdrs, loc, LASTUNSIGNED);
89
90	if (xdrs->x_op == XDR_FREE) {
91		mem_free(loc, size);
92		*pp = NULL;
93	}
94	return (stat);
95}
96
97
98/*
99 * xdr_pointer():
100 *
101 * XDR a pointer to a possibly recursive data structure. This
102 * differs with xdr_reference in that it can serialize/deserialiaze
103 * trees correctly.
104 *
105 *  What's sent is actually a union:
106 *
107 *  union object_pointer switch (boolean b) {
108 *  case TRUE: object_data data;
109 *  case FALSE: void nothing;
110 *  }
111 *
112 * > objpp: Pointer to the pointer to the object.
113 * > obj_size: size of the object.
114 * > xdr_obj: routine to XDR an object.
115 *
116 */
117bool_t
118xdr_pointer(xdrs,objpp,obj_size,xdr_obj)
119	register XDR *xdrs;
120	char **objpp;
121	u_int obj_size;
122	xdrproc_t xdr_obj;
123{
124
125	bool_t more_data;
126
127	more_data = (*objpp != NULL);
128	if (! xdr_bool(xdrs,&more_data)) {
129		return (FALSE);
130	}
131	if (! more_data) {
132		*objpp = NULL;
133		return (TRUE);
134	}
135	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
136}
137