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 <rpc/types.h>
  45 #include <rpc/xdr.h>
  46
  47 #define LASTUNSIGNED    ((u_int)0-1)
  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 size of the referneced structure.
  56  * proc is the routine to handle the referenced structure.
  57  */
  58 bool_t
  59 xdr_reference(xdrs, pp, size, proc)
  60         register XDR *xdrs;
  61         caddr_t *pp;            /* the pointer to work on */
  62         u_int size;             /* size of the object pointed to */
  63         xdrproc_t proc;         /* xdr routine to handle the object */
  64 {
  65         register caddr_t loc = *pp;
  66         register bool_t stat;
  67
  68         if (loc == NULL)
  69                 switch (xdrs->x_op) {
  70                 case XDR_FREE:
  71                         return (TRUE);
  72
  73                 case XDR_DECODE:
  74                         *pp = loc = (caddr_t) mem_alloc(size);
  75                         if (loc == NULL) {
  76                                 (void) fprintf(stderr,
  77                                     "xdr_reference: out of memory\n");
  78                                 return (FALSE);
  79                         }
  80                         bzero(loc, (int)size);
  81                         break;
  82         }
  83
  84         stat = (*proc)(xdrs, loc, LASTUNSIGNED);
  85
  86         if (xdrs->x_op == XDR_FREE) {
  87                 mem_free(loc, size);
  88                 *pp = NULL;
  89         }
  90         return (stat);
  91 }
  92
  93
  94 /*
  95  * xdr_pointer():
  96  *
  97  * XDR a pointer to a possibly recursive data structure. This
  98  * differs with xdr_reference in that it can serialize/deserialize
  99  * trees correctly.
 100  *
 101  *  What's sent is actually a union:
 102  *
 103  *  union object_pointer switch (boolean b) {
 104  *  case TRUE: object_data data;
 105  *  case FALSE: void nothing;
 106  *  }
 107  *
 108  * > objpp: Pointer to the pointer to the object.
 109  * > obj_size: size of the object.
 110  * > xdr_obj: routine to XDR an object.
 111  *
 112  */
 113 bool_t
 114 xdr_pointer(xdrs,objpp,obj_size,xdr_obj)
 115         register XDR *xdrs;
 116         char **objpp;
 117         u_int obj_size;
 118         xdrproc_t xdr_obj;
 119 {
 120
 121         bool_t more_data;
 122
 123         more_data = (*objpp != NULL);
 124         if (! xdr_bool(xdrs,&more_data)) {
 125                 return (FALSE);
 126         }
 127         if (! more_data) {
 128                 *objpp = NULL;
 129                 return (TRUE);
 130         }
 131         return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
 132 }