xref: /illumos-gate/usr/src/uts/common/rpc/xdr_refer.c (revision d48be21240dfd051b689384ce2b23479d757f2d8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Portions of this source code were derived from Berkeley 4.3 BSD
32  * under license from the Regents of the University of California.
33  */
34 
35 /*
36  * #if !defined(lint) && defined(SCCSIDS)
37  * static char sccsid[] = "@(#)xdr_refer.c 1.21 89/02/28 SMI";
38  * #endif
39  */
40 
41 /*
42  * xdr_refer.c, Generic XDR routines impelmentation.
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 <sys/param.h>
49 #include <sys/systm.h>
50 
51 #include <rpc/types.h>
52 #include <rpc/xdr.h>
53 
54 #define	LASTUNSIGNED	((uint_t)0-1)
55 
56 /*
57  * XDR an indirect pointer
58  * xdr_reference is for recursively translating a structure that is
59  * referenced by a pointer inside the structure that is currently being
60  * translated.  pp references a pointer to storage. If *pp is null
61  * the  necessary storage is allocated.
62  * size is the sizeof the referneced structure.
63  * proc is the routine to handle the referenced structure.
64  */
65 bool_t
66 xdr_reference(XDR *xdrs, caddr_t *pp, uint_t size, const xdrproc_t proc)
67 {
68 	caddr_t loc = *pp;
69 	bool_t stat;
70 
71 	if (loc == NULL) {
72 		switch (xdrs->x_op) {
73 		case XDR_FREE:
74 			return (TRUE);
75 
76 		case XDR_DECODE:
77 			*pp = loc = (caddr_t)mem_alloc(size);
78 			bzero(loc, size);
79 			break;
80 
81 		case XDR_ENCODE:
82 			break;
83 		}
84 	}
85 
86 	stat = (*proc)(xdrs, loc, LASTUNSIGNED);
87 
88 	if (xdrs->x_op == XDR_FREE) {
89 		mem_free(loc, size);
90 		*pp = NULL;
91 	}
92 	return (stat);
93 }
94 
95 /*
96  * xdr_pointer():
97  *
98  * XDR a pointer to a possibly recursive data structure. This
99  * differs with xdr_reference in that it can serialize/deserialiaze
100  * trees correctly.
101  *
102  *  What's sent is actually a union:
103  *
104  *  union object_pointer switch (boolean b) {
105  *  case TRUE: object_data data;
106  *  case FALSE: void nothing;
107  *  }
108  *
109  * > objpp: Pointer to the pointer to the object.
110  * > obj_size: size of the object.
111  * > xdr_obj: routine to XDR an object.
112  *
113  */
114 bool_t
115 xdr_pointer(XDR *xdrs, char **objpp, uint_t obj_size, const xdrproc_t xdr_obj)
116 {
117 	bool_t more_data;
118 
119 	more_data = (*objpp != NULL);
120 	if (!xdr_bool(xdrs, &more_data))
121 		return (FALSE);
122 	if (!more_data) {
123 		*objpp = NULL;
124 		return (TRUE);
125 	}
126 	return (xdr_reference(xdrs, objpp, obj_size, xdr_obj));
127 }
128