sunrpc/xdr_sizeof.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 /*
  30  * xdr_sizeof.c
  31  *
  32  * Copyright 1990 Sun Microsystems, Inc.
  33  *
  34  * General purpose routine to see how much space something will use
  35  * when serialized using XDR.
  36  */
  37
  38 #include <rpc/types.h>
  39 #include <rpc/xdr.h>
  40 #include <sys/types.h>
  41 #include <stdlib.h>
  42
  43 /* ARGSUSED */
  44 static bool_t
  45 x_putlong (XDR *xdrs, const long *longp)
  46 {
  47   xdrs->x_handy += BYTES_PER_XDR_UNIT;
  48   return TRUE;
  49 }
  50
  51 /* ARGSUSED */
  52 static bool_t
  53 x_putbytes (XDR *xdrs, const char *bp, u_int len)
  54 {
  55   xdrs->x_handy += len;
  56   return TRUE;
  57 }
  58
  59 static u_int
  60 x_getpostn (const XDR *xdrs)
  61 {
  62   return xdrs->x_handy;
  63 }
  64
  65 /* ARGSUSED */
  66 static bool_t
  67 x_setpostn (XDR *xdrs, u_int len)
  68 {
  69   /* This is not allowed */
  70   return FALSE;
  71 }
  72
  73 static long *
  74 x_inline (XDR *xdrs, int len)
  75 {
  76   if (len == 0)
  77     {
  78       return NULL;
  79     }
  80   if (xdrs->x_op != XDR_ENCODE)
  81     {
  82       return NULL;
  83     }
  84   if (len < (int) xdrs->x_base)
  85     {
  86       /* x_private was already allocated */
  87       xdrs->x_handy += len;
  88       return (long *) xdrs->x_private;
  89     }
  90   else
  91     {
  92       /* Free the earlier space and allocate new area */
  93       if (xdrs->x_private)
  94         free (xdrs->x_private);
  95       if ((xdrs->x_private = (caddr_t) malloc (len)) == NULL)
  96         {
  97           xdrs->x_base = 0;
  98           return NULL;
  99         }
 100       xdrs->x_base = (caddr_t) len;
 101       xdrs->x_handy += len;
 102       return (long *) xdrs->x_private;
 103     }
 104 }
 105
 106 static int
 107 harmless (void)
 108 {
 109   /* Always return FALSE/NULL, as the case may be */
 110   return 0;
 111 }
 112
 113 static void
 114 x_destroy (XDR *xdrs)
 115 {
 116   xdrs->x_handy = 0;
 117   xdrs->x_base = 0;
 118   if (xdrs->x_private)
 119     {
 120       free (xdrs->x_private);
 121       xdrs->x_private = NULL;
 122     }
 123   return;
 124 }
 125
 126 unsigned long
 127 xdr_sizeof (xdrproc_t func, void *data)
 128 {
 129   XDR x;
 130   struct xdr_ops ops;
 131   bool_t stat;
 132   /* to stop ANSI-C compiler from complaining */
 133   typedef bool_t (*dummyfunc1) (XDR *, long *);
 134   typedef bool_t (*dummyfunc2) (XDR *, caddr_t, u_int);
 135
 136   ops.x_putlong = x_putlong;
 137   ops.x_putbytes = x_putbytes;
 138   ops.x_inline = x_inline;
 139   ops.x_getpostn = x_getpostn;
 140   ops.x_setpostn = x_setpostn;
 141   ops.x_destroy = x_destroy;
 142
 143   /* the other harmless ones */
 144   ops.x_getlong = (dummyfunc1) harmless;
 145   ops.x_getbytes = (dummyfunc2) harmless;
 146
 147   x.x_op = XDR_ENCODE;
 148   x.x_ops = &ops;
 149   x.x_handy = 0;
 150   x.x_private = (caddr_t) NULL;
 151   x.x_base = (caddr_t) 0;
 152
 153   stat = func (&x, data);
 154   if (x.x_private)
 155     free (x.x_private);
 156   return stat == TRUE ? (unsigned) x.x_handy : 0;
 157 }