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