lib/libc/xdr/xdr_sizeof.c

   1 /*-
   2  * Copyright (c) 2010, Oracle America, Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  *       notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  *       copyright notice, this list of conditions and the following
  12  *       disclaimer in the documentation and/or other materials
  13  *       provided with the distribution.
  14  *     * Neither the name of the "Oracle America, Inc." nor the names of its
  15  *       contributors may be used to endorse or promote products derived
  16  *       from this software without specific prior written permission.
  17  *
  18  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  21  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  22  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  23  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  25  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  27  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $FreeBSD: head/lib/libc/xdr/xdr_sizeof.c 283835 2015-05-31 19:09:24Z rodrigc $
  32  */
  33
  34 /*
  35  * xdr_sizeof.c
  36  *
  37  * General purpose routine to see how much space something will use
  38  * when serialized using XDR.
  39  */
  40
  41 #include "namespace.h"
  42 #include <rpc/types.h>
  43 #include <rpc/xdr.h>
  44 #include <sys/types.h>
  45 #include <stdlib.h>
  46 #include "un-namespace.h"
  47
  48 /* ARGSUSED */
  49 static bool_t
  50 x_putlong(XDR *xdrs, const long *longp __unused)
  51 {
  52         xdrs->x_handy += BYTES_PER_XDR_UNIT;
  53         return (TRUE);
  54 }
  55
  56 /* ARGSUSED */
  57 static bool_t
  58 x_putbytes(XDR *xdrs, const char *bp __unused, u_int len)
  59 {
  60         xdrs->x_handy += len;
  61         return (TRUE);
  62 }
  63
  64 static u_int
  65 x_getpostn(XDR *xdrs)
  66 {
  67         return (xdrs->x_handy);
  68 }
  69
  70 /* ARGSUSED */
  71 static bool_t
  72 x_setpostn(XDR *xdrs __unused, u_int pos __unused)
  73 {
  74         /* This is not allowed */
  75         return (FALSE);
  76 }
  77
  78 static int32_t *
  79 x_inline(XDR *xdrs, u_int len)
  80 {
  81         if (len == 0) {
  82                 return (NULL);
  83         }
  84         if (xdrs->x_op != XDR_ENCODE) {
  85                 return (NULL);
  86         }
  87         if (len < (u_int)(uintptr_t)xdrs->x_base) {
  88                 /* x_private was already allocated */
  89                 xdrs->x_handy += len;
  90                 return ((int32_t *) xdrs->x_private);
  91         } else {
  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                         xdrs->x_base = 0;
  97                         return (NULL);
  98                 }
  99                 xdrs->x_base = (caddr_t)(uintptr_t)len;
 100                 xdrs->x_handy += len;
 101                 return ((int32_t *) xdrs->x_private);
 102         }
 103 }
 104
 105 static int
 106 harmless(void)
 107 {
 108         /* Always return FALSE/NULL, as the case may be */
 109         return (0);
 110 }
 111
 112 static void
 113 x_destroy(XDR *xdrs)
 114 {
 115         xdrs->x_handy = 0;
 116         xdrs->x_base = 0;
 117         if (xdrs->x_private) {
 118                 free(xdrs->x_private);
 119                 xdrs->x_private = NULL;
 120         }
 121         return;
 122 }
 123
 124 unsigned long
 125 xdr_sizeof(xdrproc_t func, void *data)
 126 {
 127         XDR x;
 128         struct xdr_ops ops;
 129         bool_t stat;
 130         /* to stop ANSI-C compiler from complaining */
 131         typedef  bool_t (* dummyfunc1)(XDR *, long *);
 132         typedef  bool_t (* dummyfunc2)(XDR *, caddr_t, u_int);
 133
 134         ops.x_putlong = x_putlong;
 135         ops.x_putbytes = x_putbytes;
 136         ops.x_inline = x_inline;
 137         ops.x_getpostn = x_getpostn;
 138         ops.x_setpostn = x_setpostn;
 139         ops.x_destroy = x_destroy;
 140
 141         /* the other harmless ones */
 142         ops.x_getlong =  (dummyfunc1) harmless;
 143         ops.x_getbytes = (dummyfunc2) harmless;
 144
 145         x.x_op = XDR_ENCODE;
 146         x.x_ops = &ops;
 147         x.x_handy = 0;
 148         x.x_private = NULL;
 149         x.x_base = (caddr_t) 0;
 150
 151         stat = func(&x, data);
 152         if (x.x_private)
 153                 free(x.x_private);
 154         return (stat == TRUE ? (unsigned) x.x_handy: 0);
 155 }