sunrpc/xdr_ref.c

   1 /* @(#)xdr_reference.c  2.1 88/07/29 4.0 RPCSRC */
   2 /*
   3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   4  * unrestricted use provided that this legend is included on all tape
   5  * media and as a part of the software program in whole or part.  Users
   6  * may copy or modify Sun RPC without charge, but are not authorized
   7  * to license or distribute it to anyone else except as part of a product or
   8  * program developed by the user.
   9  *
  10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  13  *
  14  * Sun RPC is provided with no support and without any obligation on the
  15  * part of Sun Microsystems, Inc. to assist in its use, correction,
  16  * modification or enhancement.
  17  *
  18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  20  * OR ANY PART THEREOF.
  21  *
  22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  23  * or profits or other special, indirect and consequential damages, even if
  24  * Sun has been advised of the possibility of such damages.
  25  *
  26  * Sun Microsystems, Inc.
  27  * 2550 Garcia Avenue
  28  * Mountain View, California  94043
  29  */
  30 #if !defined(lint) && defined(SCCSIDS)
  31 static char sccsid[] = "@(#)xdr_reference.c 1.11 87/08/11 SMI";
  32 #endif
  33
  34 /*
  35  * xdr_reference.c, Generic XDR routines implementation.
  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 <string.h>
  45 #include <rpc/types.h>
  46 #include <rpc/xdr.h>
  47
  48 #define LASTUNSIGNED    ((u_int)0-1)
  49
  50 /*
  51  * XDR an indirect pointer
  52  * xdr_reference is for recursively translating a structure that is
  53  * referenced by a pointer inside the structure that is currently being
  54  * translated.  pp references a pointer to storage. If *pp is null
  55  * the  necessary storage is allocated.
  56  * size is the size of the referneced structure.
  57  * proc is the routine to handle the referenced structure.
  58  */
  59 bool_t
  60 xdr_reference (xdrs, pp, size, proc)
  61      XDR *xdrs;
  62      caddr_t *pp;               /* the pointer to work on */
  63      u_int size;                /* size of the object pointed to */
  64      xdrproc_t proc;            /* xdr routine to handle the object */
  65 {
  66   caddr_t loc = *pp;
  67   bool_t stat;
  68
  69   if (loc == NULL)
  70     switch (xdrs->x_op)
  71       {
  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           {
  79             (void) fputs (_("xdr_reference: out of memory\n"), stderr);
  80             return FALSE;
  81           }
  82         bzero (loc, (int) size);
  83         break;
  84       default:
  85         break;
  86       }
  87
  88   stat = (*proc) (xdrs, loc, LASTUNSIGNED);
  89
  90   if (xdrs->x_op == XDR_FREE)
  91     {
  92       mem_free (loc, size);
  93       *pp = NULL;
  94     }
  95   return stat;
  96 }
  97
  98
  99 /*
 100  * xdr_pointer():
 101  *
 102  * XDR a pointer to a possibly recursive data structure. This
 103  * differs with xdr_reference in that it can serialize/deserialize
 104  * trees correctly.
 105  *
 106  *  What's sent is actually a union:
 107  *
 108  *  union object_pointer switch (boolean b) {
 109  *  case TRUE: object_data data;
 110  *  case FALSE: void nothing;
 111  *  }
 112  *
 113  * > objpp: Pointer to the pointer to the object.
 114  * > obj_size: size of the object.
 115  * > xdr_obj: routine to XDR an object.
 116  *
 117  */
 118 bool_t
 119 xdr_pointer (xdrs, objpp, obj_size, xdr_obj)
 120      XDR *xdrs;
 121      char **objpp;
 122      u_int obj_size;
 123      xdrproc_t xdr_obj;
 124 {
 125
 126   bool_t more_data;
 127
 128   more_data = (*objpp != NULL);
 129   if (!xdr_bool (xdrs, &more_data))
 130     {
 131       return FALSE;
 132     }
 133   if (!more_data)
 134     {
 135       *objpp = NULL;
 136       return TRUE;
 137     }
 138   return xdr_reference (xdrs, objpp, obj_size, xdr_obj);
 139 }