xref: /illumos-gate/usr/src/lib/libnsl/rpc/xdr_refer.c (revision 22cc5755)
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 /*
24  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
29 /* All Rights Reserved */
30 /*
31  * Portions of this source code were derived from Berkeley
32  * 4.3 BSD under license from the Regents of the University of
33  * California.
34  */
35 
36 /*
37  * Generic XDR routines impelmentation.
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 #include "mt.h"
43 #include <sys/types.h>
44 #include <syslog.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <rpc/types.h>
48 #include <rpc/xdr.h>
49 #include <memory.h>
50 
51 #define	LASTUNSIGNED	((uint_t)0-1)
52 char mem_err_msg_ref[] = "xdr_reference: out of memory";
53 
54 /*
55  * XDR an indirect pointer
56  * xdr_reference is for recursively translating a structure that is
57  * referenced by a pointer inside the structure that is currently being
58  * translated.  pp references a pointer to storage. If *pp is null
59  * the  necessary storage is allocated.
60  * size is the sizeof the referneced structure.
61  * proc is the routine to handle the referenced structure.
62  */
63 bool_t
xdr_reference(XDR * xdrs,caddr_t * pp,uint_t size,const xdrproc_t proc)64 xdr_reference(XDR *xdrs, caddr_t *pp, uint_t size, const xdrproc_t proc)
65 {
66 	caddr_t loc = *pp;
67 	bool_t stat;
68 
69 	/* Make sure x_op contains a valid value */
70 	if (xdrs->x_op != XDR_ENCODE &&
71 	    xdrs->x_op != XDR_DECODE &&
72 	    xdrs->x_op != XDR_FREE)
73 		return (FALSE);
74 
75 	if (loc == NULL)
76 		switch (xdrs->x_op) {
77 		case XDR_FREE:
78 			return (TRUE);
79 		case XDR_DECODE:
80 			*pp = loc = malloc(size);
81 			if (loc == NULL) {
82 				(void) syslog(LOG_ERR, mem_err_msg_ref);
83 				return (FALSE);
84 			}
85 			(void) memset(loc, 0, (int)size);
86 			break;
87 	}
88 
89 	stat = (*proc)(xdrs, loc, LASTUNSIGNED);
90 
91 	if (xdrs->x_op == XDR_FREE) {
92 		free(loc);
93 		*pp = NULL;
94 	}
95 	return (stat);
96 }
97 
98 
99 /*
100  * xdr_pointer():
101  *
102  * XDR a pointer to a possibly recursive data structure. This
103  * differs with xdr_reference in that it can serialize/deserialiaze
104  * trees correctly.
105  *
106  *  What's sent is actually a union:
107  *
108  *  union object_pointer switch (boolean b) {
109  *  case TRUE: object_data data;
110  *  case FALSE: void nothing;
111  *  }
112  *
113  * > objpp: Pointer to the pointer to the object.
114  * > obj_size: size of the object.
115  * > xdr_obj: routine to XDR an object.
116  *
117  */
118 bool_t
xdr_pointer(XDR * xdrs,char ** objpp,uint_t obj_size,const xdrproc_t xdr_obj)119 xdr_pointer(XDR *xdrs, char **objpp, uint_t obj_size, const xdrproc_t xdr_obj)
120 {
121 	bool_t more_data;
122 
123 	more_data = (*objpp != NULL);
124 	if (!xdr_bool(xdrs, &more_data))
125 		return (FALSE);
126 	if (!more_data) {
127 		*objpp = NULL;
128 		return (TRUE);
129 	}
130 	return (xdr_reference(xdrs, objpp, obj_size, xdr_obj));
131 }
132