lib/libc/xdr/xdr_reference.c

   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  * @(#)xdr_reference.c 1.11 87/08/11 SMI
  30  * @(#)xdr_reference.c  2.1 88/07/29 4.0 RPCSRC
  31  * $FreeBSD: src/lib/libc/xdr/xdr_reference.c,v 1.8 1999/08/28 00:02:56 peter Exp $
  32  * $DragonFly: src/lib/libc/xdr/xdr_reference.c,v 1.4 2005/12/05 00:47:57 swildner Exp $
  33  */
  34
  35 /*
  36  * xdr_reference.c, Generic XDR routines impelmentation.
  37  *
  38  * Copyright (C) 1987, Sun Microsystems, Inc.
  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 <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <rpc/types.h>
  48 #include <rpc/xdr.h>
  49
  50 #define LASTUNSIGNED ((u_int) 0-1)
  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  * Parameters:
  62  *     pp:      the pointer to work on
  63  *     size:    size of the object pointed to
  64  *     proc:    xdr routine to handle the object
  65  */
  66 bool_t
  67 xdr_reference(XDR *xdrs, caddr_t *pp, u_int size, xdrproc_t proc)
  68 {
  69         caddr_t loc = *pp;
  70         bool_t stat;
  71
  72         if (loc == NULL)
  73                 switch (xdrs->x_op) {
  74                 case XDR_FREE:
  75                         return (TRUE);
  76
  77                 case XDR_DECODE:
  78                         *pp = loc = (caddr_t) mem_alloc(size);
  79                         if (loc == NULL) {
  80                                 fprintf(stderr,
  81                                     "xdr_reference: out of memory\n");
  82                                 return (FALSE);
  83                         }
  84                         memset(loc, 0, (int)size);
  85                         break;
  86                 case XDR_ENCODE:
  87                         break;
  88         }
  89
  90         stat = (*proc)(xdrs, loc, LASTUNSIGNED);
  91
  92         if (xdrs->x_op == XDR_FREE) {
  93                 mem_free(loc, size);
  94                 *pp = NULL;
  95         }
  96         return (stat);
  97 }
  98
  99
 100 /*
 101  * xdr_pointer():
 102  *
 103  * XDR a pointer to a possibly recursive data structure. This
 104  * differs with xdr_reference in that it can serialize/deserialiaze
 105  * trees correctly.
 106  *
 107  *  What's sent is actually a union:
 108  *
 109  *  union object_pointer switch (boolean b) {
 110  *  case TRUE: object_data data;
 111  *  case FALSE: void nothing;
 112  *  }
 113  *
 114  * > objpp: Pointer to the pointer to the object.
 115  * > obj_size: size of the object.
 116  * > xdr_obj: routine to XDR an object.
 117  *
 118  */
 119 bool_t
 120 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
 121 {
 122         bool_t more_data;
 123
 124         more_data = (*objpp != NULL);
 125         if (! xdr_bool(xdrs,&more_data)) {
 126                 return (FALSE);
 127         }
 128         if (! more_data) {
 129                 *objpp = NULL;
 130                 return (TRUE);
 131         }
 132         return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
 133 }