xref: /freebsd/lib/libc/xdr/xdr_reference.c (revision edf8578117e8844e02c0121147f45e4609b30680)
1 /*	$NetBSD: xdr_reference.c,v 1.13 2000/01/22 22:19:18 mycroft Exp	$ */
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 2010, Oracle America, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are
10  * met:
11  *
12  *     * Redistributions of source code must retain the above copyright
13  *       notice, this list of conditions and the following disclaimer.
14  *     * Redistributions in binary form must reproduce the above
15  *       copyright notice, this list of conditions and the following
16  *       disclaimer in the documentation and/or other materials
17  *       provided with the distribution.
18  *     * Neither the name of the "Oracle America, Inc." nor the names of its
19  *       contributors may be used to endorse or promote products derived
20  *       from this software without specific prior written permission.
21  *
22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
29  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
33  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char *sccsid2 = "@(#)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 #endif
40 #include <sys/cdefs.h>
41 /*
42  * xdr_reference.c, Generic XDR routines implementation.
43  *
44  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
45  * "pointers".  See xdr.h for more info on the interface to xdr.
46  */
47 
48 #include "namespace.h"
49 #include <err.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 
54 #include <rpc/types.h>
55 #include <rpc/xdr.h>
56 #include "libc_private.h"
57 
58 /*
59  * XDR an indirect pointer
60  * xdr_reference is for recursively translating a structure that is
61  * referenced by a pointer inside the structure that is currently being
62  * translated.  pp references a pointer to storage. If *pp is null
63  * the  necessary storage is allocated.
64  * size is the sizeof the referneced structure.
65  * proc is the routine to handle the referenced structure.
66  */
67 bool_t
68 xdr_reference(XDR *xdrs, caddr_t *pp, u_int size, xdrproc_t proc)
69 /*
70  *	XDR *xdrs;
71  *	caddr_t *pp;		// the pointer to work on
72  *	u_int size;		// size of the object pointed to
73  *	xdrproc_t proc;		// xdr routine to handle the object
74  */
75 {
76 	caddr_t loc = *pp;
77 	bool_t stat;
78 
79 	if (loc == NULL)
80 		switch (xdrs->x_op) {
81 		case XDR_FREE:
82 			return (TRUE);
83 
84 		case XDR_DECODE:
85 			*pp = loc = (caddr_t) mem_alloc(size);
86 			if (loc == NULL) {
87 				warnx("xdr_reference: out of memory");
88 				return (FALSE);
89 			}
90 			memset(loc, 0, size);
91 			break;
92 
93 		case XDR_ENCODE:
94 			break;
95 		}
96 
97 	stat = (*proc)(xdrs, loc);
98 
99 	if (xdrs->x_op == XDR_FREE) {
100 		mem_free(loc, size);
101 		*pp = NULL;
102 	}
103 	return (stat);
104 }
105 
106 
107 /*
108  * xdr_pointer():
109  *
110  * XDR a pointer to a possibly recursive data structure. This
111  * differs with xdr_reference in that it can serialize/deserialiaze
112  * trees correctly.
113  *
114  *  What's sent is actually a union:
115  *
116  *  union object_pointer switch (boolean b) {
117  *  case TRUE: object_data data;
118  *  case FALSE: void nothing;
119  *  }
120  *
121  * > objpp: Pointer to the pointer to the object.
122  * > obj_size: size of the object.
123  * > xdr_obj: routine to XDR an object.
124  *
125  */
126 bool_t
127 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
128 {
129 
130 	bool_t more_data;
131 
132 	more_data = (*objpp != NULL);
133 	if (! xdr_bool(xdrs,&more_data)) {
134 		return (FALSE);
135 	}
136 	if (! more_data) {
137 		*objpp = NULL;
138 		return (TRUE);
139 	}
140 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
141 }
142