usr/src/uts/common/rpc/xdr_refer.c

   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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  36
  37 /*
  38  * #if !defined(lint) && defined(SCCSIDS)
  39  * static char sccsid[] = "@(#)xdr_refer.c 1.21 89/02/28 SMI";
  40  * #endif
  41  */
  42
  43 /*
  44  * xdr_refer.c, Generic XDR routines impelmentation.
  45  *
  46  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
  47  * "pointers".  See xdr.h for more info on the interface to xdr.
  48  */
  49
  50 #include <sys/param.h>
  51 #include <sys/systm.h>
  52
  53 #include <rpc/types.h>
  54 #include <rpc/xdr.h>
  55
  56 #define LASTUNSIGNED    ((uint_t)0-1)
  57
  58 /*
  59  * XDR an indirect pointer
  60  * xdr_reference is for recursively translating a structure that is
  61  * referenced by a pointer inside the structure that is currently being
  62  * translated.  pp references a pointer to storage. If *pp is null
  63  * the  necessary storage is allocated.
  64  * size is the sizeof the referneced structure.
  65  * proc is the routine to handle the referenced structure.
  66  */
  67 bool_t
  68 xdr_reference(XDR *xdrs, caddr_t *pp, uint_t size, const xdrproc_t proc)
  69 {
  70         caddr_t loc = *pp;
  71         bool_t stat;
  72
  73         if (loc == NULL) {
  74                 switch (xdrs->x_op) {
  75                 case XDR_FREE:
  76                         return (TRUE);
  77
  78                 case XDR_DECODE:
  79                         *pp = loc = (caddr_t)mem_alloc(size);
  80                         bzero(loc, size);
  81                         break;
  82
  83                 case XDR_ENCODE:
  84                         break;
  85                 }
  86         }
  87
  88         stat = (*proc)(xdrs, loc, LASTUNSIGNED);
  89
  90         if (xdrs->x_op == XDR_FREE) {
  91                 mem_free(loc, size);
  92                 *pp = NULL;
  93         }
  94         return (stat);
  95 }
  96
  97 /*
  98  * xdr_pointer():
  99  *
 100  * XDR a pointer to a possibly recursive data structure. This
 101  * differs with xdr_reference in that it can serialize/deserialiaze
 102  * trees correctly.
 103  *
 104  *  What's sent is actually a union:
 105  *
 106  *  union object_pointer switch (boolean b) {
 107  *  case TRUE: object_data data;
 108  *  case FALSE: void nothing;
 109  *  }
 110  *
 111  * > objpp: Pointer to the pointer to the object.
 112  * > obj_size: size of the object.
 113  * > xdr_obj: routine to XDR an object.
 114  *
 115  */
 116 bool_t
 117 xdr_pointer(XDR *xdrs, char **objpp, uint_t obj_size, const xdrproc_t xdr_obj)
 118 {
 119         bool_t more_data;
 120
 121         more_data = (*objpp != NULL);
 122         if (!xdr_bool(xdrs, &more_data))
 123                 return (FALSE);
 124         if (!more_data) {
 125                 *objpp = NULL;
 126                 return (TRUE);
 127         }
 128         return (xdr_reference(xdrs, objpp, obj_size, xdr_obj));
 129 }