xref: /freebsd/lib/libc/xdr/xdr_reference.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 __FBSDID("$FreeBSD$");
42 
43 /*
44  * xdr_reference.c, Generic XDR routines implementation.
45  *
46  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
47  * "pointers".  See xdr.h for more info on the interface to xdr.
48  */
49 
50 #include "namespace.h"
51 #include <err.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 
56 #include <rpc/types.h>
57 #include <rpc/xdr.h>
58 #include "libc_private.h"
59 
60 /*
61  * XDR an indirect pointer
62  * xdr_reference is for recursively translating a structure that is
63  * referenced by a pointer inside the structure that is currently being
64  * translated.  pp references a pointer to storage. If *pp is null
65  * the  necessary storage is allocated.
66  * size is the sizeof the referneced structure.
67  * proc is the routine to handle the referenced structure.
68  */
69 bool_t
70 xdr_reference(XDR *xdrs, caddr_t *pp, u_int size, xdrproc_t proc)
71 /*
72  *	XDR *xdrs;
73  *	caddr_t *pp;		// the pointer to work on
74  *	u_int size;		// size of the object pointed to
75  *	xdrproc_t proc;		// xdr routine to handle the object
76  */
77 {
78 	caddr_t loc = *pp;
79 	bool_t stat;
80 
81 	if (loc == NULL)
82 		switch (xdrs->x_op) {
83 		case XDR_FREE:
84 			return (TRUE);
85 
86 		case XDR_DECODE:
87 			*pp = loc = (caddr_t) mem_alloc(size);
88 			if (loc == NULL) {
89 				warnx("xdr_reference: out of memory");
90 				return (FALSE);
91 			}
92 			memset(loc, 0, size);
93 			break;
94 
95 		case XDR_ENCODE:
96 			break;
97 		}
98 
99 	stat = (*proc)(xdrs, loc);
100 
101 	if (xdrs->x_op == XDR_FREE) {
102 		mem_free(loc, size);
103 		*pp = NULL;
104 	}
105 	return (stat);
106 }
107 
108 
109 /*
110  * xdr_pointer():
111  *
112  * XDR a pointer to a possibly recursive data structure. This
113  * differs with xdr_reference in that it can serialize/deserialiaze
114  * trees correctly.
115  *
116  *  What's sent is actually a union:
117  *
118  *  union object_pointer switch (boolean b) {
119  *  case TRUE: object_data data;
120  *  case FALSE: void nothing;
121  *  }
122  *
123  * > objpp: Pointer to the pointer to the object.
124  * > obj_size: size of the object.
125  * > xdr_obj: routine to XDR an object.
126  *
127  */
128 bool_t
129 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
130 {
131 
132 	bool_t more_data;
133 
134 	more_data = (*objpp != NULL);
135 	if (! xdr_bool(xdrs,&more_data)) {
136 		return (FALSE);
137 	}
138 	if (! more_data) {
139 		*objpp = NULL;
140 		return (TRUE);
141 	}
142 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
143 }
144