xref: /openbsd-src/lib/libc/rpc/xdr_reference.c (revision c5f4fad510dd427c0c20c0f4d164f60ce24651b6)
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 *rcsid = "$OpenBSD: xdr_reference.c,v 1.5 2005/04/01 07:44:04 otto Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 
34 /*
35  * xdr_reference.c, Generic XDR routines impelmentation.
36  *
37  * Copyright (C) 1987, Sun Microsystems, Inc.
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 
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
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 				(void) fprintf(stderr,
76 				    "xdr_reference: out of memory\n");
77 				return (FALSE);
78 			}
79 			memset(loc, 0, (int)size);
80 			break;
81 	}
82 
83 	stat = (*proc)(xdrs, loc);
84 
85 	if (xdrs->x_op == XDR_FREE) {
86 		mem_free(loc, size);
87 		*pp = NULL;
88 	}
89 	return (stat);
90 }
91 
92 
93 /*
94  * xdr_pointer():
95  *
96  * XDR a pointer to a possibly recursive data structure. This
97  * differs with xdr_reference in that it can serialize/deserialiaze
98  * trees correctly.
99  *
100  *  What's sent is actually a union:
101  *
102  *  union object_pointer switch (boolean b) {
103  *  case TRUE: object_data data;
104  *  case FALSE: void nothing;
105  *  }
106  *
107  * > objpp: Pointer to the pointer to the object.
108  * > obj_size: size of the object.
109  * > xdr_obj: routine to XDR an object.
110  *
111  */
112 bool_t
113 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
114 {
115 
116 	bool_t more_data;
117 
118 	more_data = (*objpp != NULL);
119 	if (! xdr_bool(xdrs,&more_data)) {
120 		return (FALSE);
121 	}
122 	if (! more_data) {
123 		*objpp = NULL;
124 		return (TRUE);
125 	}
126 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
127 }
128