xref: /freebsd/sys/xdr/xdr_reference.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*	$NetBSD: xdr_reference.c,v 1.13 2000/01/22 22:19:18 mycroft Exp	$ */
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 #include <sys/cdefs.h>
33 /*
34  * xdr_reference.c, Generic XDR routines implementation.
35  *
36  * Copyright (C) 1987, Sun Microsystems, Inc.
37  *
38  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
39  * "pointers".  See xdr.h for more info on the interface to xdr.
40  */
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/malloc.h>
45 
46 #include <rpc/types.h>
47 #include <rpc/xdr.h>
48 
49 /*
50  * XDR an indirect pointer
51  * xdr_reference is for recursively translating a structure that is
52  * referenced by a pointer inside the structure that is currently being
53  * translated.  pp references a pointer to storage. If *pp is null
54  * the  necessary storage is allocated.
55  * size is the sizeof the referneced structure.
56  * proc is the routine to handle the referenced structure.
57  */
58 bool_t
59 xdr_reference(XDR *xdrs,
60     caddr_t *pp,		/* the pointer to work on */
61     u_int size,			/* size of the object pointed to */
62     xdrproc_t proc)		/* xdr routine to handle the object */
63 {
64 	caddr_t loc = *pp;
65 	bool_t stat;
66 
67 	if (loc == NULL)
68 		switch (xdrs->x_op) {
69 		case XDR_FREE:
70 			return (TRUE);
71 
72 		case XDR_DECODE:
73 			*pp = loc = (caddr_t) mem_alloc(size);
74 			if (loc == NULL) {
75 				printf("xdr_reference: out of memory");
76 				return (FALSE);
77 			}
78 			memset(loc, 0, size);
79 			break;
80 
81 		case XDR_ENCODE:
82 			break;
83 		}
84 
85 	stat = (*proc)(xdrs, loc);
86 
87 	if (xdrs->x_op == XDR_FREE) {
88 		mem_free(loc, size);
89 		*pp = NULL;
90 	}
91 	return (stat);
92 }
93 
94 /*
95  * xdr_pointer():
96  *
97  * XDR a pointer to a possibly recursive data structure. This
98  * differs with xdr_reference in that it can serialize/deserialiaze
99  * trees correctly.
100  *
101  *  What's sent is actually a union:
102  *
103  *  union object_pointer switch (boolean b) {
104  *  case TRUE: object_data data;
105  *  case FALSE: void nothing;
106  *  }
107  *
108  * > objpp: Pointer to the pointer to the object.
109  * > obj_size: size of the object.
110  * > xdr_obj: routine to XDR an object.
111  *
112  */
113 bool_t
114 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
115 {
116 
117 	bool_t more_data;
118 
119 	more_data = (*objpp != NULL);
120 	if (! xdr_bool(xdrs,&more_data)) {
121 		return (FALSE);
122 	}
123 	if (! more_data) {
124 		*objpp = NULL;
125 		return (TRUE);
126 	}
127 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
128 }
129