xref: /freebsd/lib/libc/xdr/xdr_reference.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 /*static char *sccsid = "from: @(#)xdr_reference.c 1.11 87/08/11 SMI";*/
32 /*static char *sccsid = "from: @(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC";*/
33 static char *rcsid = "$Id: xdr_reference.c,v 1.1 1993/10/27 05:41:13 paul Exp $";
34 #endif
35 
36 /*
37  * xdr_reference.c, Generic XDR routines impelmentation.
38  *
39  * Copyright (C) 1987, Sun Microsystems, Inc.
40  *
41  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
42  * "pointers".  See xdr.h for more info on the interface to xdr.
43  */
44 
45 #include <stdio.h>
46 #include <rpc/types.h>
47 #include <rpc/xdr.h>
48 
49 #define LASTUNSIGNED	((u_int)0-1)
50 
51 /*
52  * XDR an indirect pointer
53  * xdr_reference is for recursively translating a structure that is
54  * referenced by a pointer inside the structure that is currently being
55  * translated.  pp references a pointer to storage. If *pp is null
56  * the  necessary storage is allocated.
57  * size is the sizeof the referneced structure.
58  * proc is the routine to handle the referenced structure.
59  */
60 bool_t
61 xdr_reference(xdrs, pp, size, proc)
62 	register XDR *xdrs;
63 	caddr_t *pp;		/* the pointer to work on */
64 	u_int size;		/* size of the object pointed to */
65 	xdrproc_t proc;		/* xdr routine to handle the object */
66 {
67 	register caddr_t loc = *pp;
68 	register bool_t stat;
69 
70 	if (loc == NULL)
71 		switch (xdrs->x_op) {
72 		case XDR_FREE:
73 			return (TRUE);
74 
75 		case XDR_DECODE:
76 			*pp = loc = (caddr_t) mem_alloc(size);
77 			if (loc == NULL) {
78 				(void) fprintf(stderr,
79 				    "xdr_reference: out of memory\n");
80 				return (FALSE);
81 			}
82 			bzero(loc, (int)size);
83 			break;
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 /*
97  * xdr_pointer():
98  *
99  * XDR a pointer to a possibly recursive data structure. This
100  * differs with xdr_reference in that it can serialize/deserialiaze
101  * trees correctly.
102  *
103  *  What's sent is actually a union:
104  *
105  *  union object_pointer switch (boolean b) {
106  *  case TRUE: object_data data;
107  *  case FALSE: void nothing;
108  *  }
109  *
110  * > objpp: Pointer to the pointer to the object.
111  * > obj_size: size of the object.
112  * > xdr_obj: routine to XDR an object.
113  *
114  */
115 bool_t
116 xdr_pointer(xdrs,objpp,obj_size,xdr_obj)
117 	register XDR *xdrs;
118 	char **objpp;
119 	u_int obj_size;
120 	xdrproc_t xdr_obj;
121 {
122 
123 	bool_t more_data;
124 
125 	more_data = (*objpp != NULL);
126 	if (! xdr_bool(xdrs,&more_data)) {
127 		return (FALSE);
128 	}
129 	if (! more_data) {
130 		*objpp = NULL;
131 		return (TRUE);
132 	}
133 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
134 }
135