sunrpc/xdr_mem.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 /*
  31  * xdr_mem.h, XDR implementation using memory buffers.
  32  *
  33  * Copyright (C) 1984, Sun Microsystems, Inc.
  34  *
  35  * If you have some data to be interpreted as external data representation
  36  * or to be converted to external data representation in a memory buffer,
  37  * then this is the package for you.
  38  *
  39  */
  40
  41 #include <string.h>
  42 #include <limits.h>
  43 #include <rpc/rpc.h>
  44
  45 static bool_t xdrmem_getlong (XDR *, long *);
  46 static bool_t xdrmem_putlong (XDR *, const long *);
  47 static bool_t xdrmem_getbytes (XDR *, caddr_t, u_int);
  48 static bool_t xdrmem_putbytes (XDR *, const char *, u_int);
  49 static u_int xdrmem_getpos (const XDR *);
  50 static bool_t xdrmem_setpos (XDR *, u_int);
  51 static int32_t *xdrmem_inline (XDR *, u_int);
  52 static void xdrmem_destroy (XDR *);
  53 static bool_t xdrmem_getint32 (XDR *, int32_t *);
  54 static bool_t xdrmem_putint32 (XDR *, const int32_t *);
  55
  56 static const struct xdr_ops xdrmem_ops =
  57 {
  58   xdrmem_getlong,
  59   xdrmem_putlong,
  60   xdrmem_getbytes,
  61   xdrmem_putbytes,
  62   xdrmem_getpos,
  63   xdrmem_setpos,
  64   xdrmem_inline,
  65   xdrmem_destroy,
  66   xdrmem_getint32,
  67   xdrmem_putint32
  68 };
  69
  70 /*
  71  * The procedure xdrmem_create initializes a stream descriptor for a
  72  * memory buffer.
  73  */
  74 void
  75 xdrmem_create (XDR *xdrs, const caddr_t addr, u_int size, enum xdr_op op)
  76 {
  77   xdrs->x_op = op;
  78   /* We have to add the const since the `struct xdr_ops' in `struct XDR'
  79      is not `const'.  */
  80   xdrs->x_ops = (struct xdr_ops *) &xdrmem_ops;
  81   xdrs->x_private = xdrs->x_base = addr;
  82   xdrs->x_handy = size;
  83 }
  84 INTDEF(xdrmem_create)
  85
  86 /*
  87  * Nothing needs to be done for the memory case.  The argument is clearly
  88  * const.
  89  */
  90
  91 static void
  92 xdrmem_destroy (XDR *xdrs)
  93 {
  94 }
  95
  96 /*
  97  * Gets the next word from the memory referenced by xdrs and places it
  98  * in the long pointed to by lp.  It then increments the private word to
  99  * point at the next element.  Neither object pointed to is const
 100  */
 101 static bool_t
 102 xdrmem_getlong (XDR *xdrs, long *lp)
 103 {
 104   if (xdrs->x_handy < 4)
 105     return FALSE;
 106   xdrs->x_handy -= 4;
 107   *lp = (int32_t) ntohl ((*((int32_t *) (xdrs->x_private))));
 108   xdrs->x_private += 4;
 109   return TRUE;
 110 }
 111
 112 /*
 113  * Puts the long pointed to by lp in the memory referenced by xdrs.  It
 114  * then increments the private word to point at the next element.  The
 115  * long pointed at is const
 116  */
 117 static bool_t
 118 xdrmem_putlong (XDR *xdrs, const long *lp)
 119 {
 120   if (xdrs->x_handy < 4)
 121     return FALSE;
 122   xdrs->x_handy -= 4;
 123   *(int32_t *) xdrs->x_private = htonl (*lp);
 124   xdrs->x_private += 4;
 125   return TRUE;
 126 }
 127
 128 /*
 129  * Gets an unaligned number of bytes from the xdrs structure and writes them
 130  * to the address passed in addr.  Be very careful when calling this routine
 131  * as it could leave the xdrs pointing to an unaligned structure which is not
 132  * a good idea.  None of the things pointed to are const.
 133  */
 134 static bool_t
 135 xdrmem_getbytes (XDR *xdrs, caddr_t addr, u_int len)
 136 {
 137   if (xdrs->x_handy < len)
 138     return FALSE;
 139   xdrs->x_handy -= len;
 140   memcpy (addr, xdrs->x_private, len);
 141   xdrs->x_private += len;
 142   return TRUE;
 143 }
 144
 145 /*
 146  * The complementary function to the above.  The same warnings apply about
 147  * unaligned data.  The source address is const.
 148  */
 149 static bool_t
 150 xdrmem_putbytes (XDR *xdrs, const char *addr, u_int len)
 151 {
 152   if (xdrs->x_handy < len)
 153     return FALSE;
 154   xdrs->x_handy -= len;
 155   memcpy (xdrs->x_private, addr, len);
 156   xdrs->x_private += len;
 157   return TRUE;
 158 }
 159
 160 /*
 161  * Not sure what this one does.  But it clearly doesn't modify the contents
 162  * of xdrs.  **FIXME** does this not assume u_int == u_long?
 163  */
 164 static u_int
 165 xdrmem_getpos (const XDR *xdrs)
 166 {
 167   return (u_long) xdrs->x_private - (u_long) xdrs->x_base;
 168 }
 169
 170 /*
 171  * xdrs modified
 172  */
 173 static bool_t
 174 xdrmem_setpos (xdrs, pos)
 175      XDR *xdrs;
 176      u_int pos;
 177 {
 178   caddr_t newaddr = xdrs->x_base + pos;
 179   caddr_t lastaddr = xdrs->x_private + xdrs->x_handy;
 180
 181   if ((long) newaddr > (long) lastaddr
 182       || (UINT_MAX < LONG_MAX
 183           && (long) UINT_MAX < (long) lastaddr - (long) newaddr))
 184     return FALSE;
 185   xdrs->x_private = newaddr;
 186   xdrs->x_handy = (long) lastaddr - (long) newaddr;
 187   return TRUE;
 188 }
 189
 190 /*
 191  * xdrs modified
 192  */
 193 static int32_t *
 194 xdrmem_inline (XDR *xdrs, u_int len)
 195 {
 196   int32_t *buf = 0;
 197
 198   if (xdrs->x_handy >= len)
 199     {
 200       xdrs->x_handy -= len;
 201       buf = (int32_t *) xdrs->x_private;
 202       xdrs->x_private += len;
 203     }
 204   return buf;
 205 }
 206
 207 /*
 208  * Gets the next word from the memory referenced by xdrs and places it
 209  * in the int pointed to by ip.  It then increments the private word to
 210  * point at the next element.  Neither object pointed to is const
 211  */
 212 static bool_t
 213 xdrmem_getint32 (XDR *xdrs, int32_t *ip)
 214 {
 215   if (xdrs->x_handy < 4)
 216     return FALSE;
 217   xdrs->x_handy -= 4;
 218   *ip = ntohl ((*((int32_t *) (xdrs->x_private))));
 219   xdrs->x_private += 4;
 220   return TRUE;
 221 }
 222
 223 /*
 224  * Puts the long pointed to by lp in the memory referenced by xdrs.  It
 225  * then increments the private word to point at the next element.  The
 226  * long pointed at is const
 227  */
 228 static bool_t
 229 xdrmem_putint32 (XDR *xdrs, const int32_t *ip)
 230 {
 231   if (xdrs->x_handy < 4)
 232     return FALSE;
 233   xdrs->x_handy -= 4;
 234   *(int32_t *) xdrs->x_private = htonl (*ip);
 235   xdrs->x_private += 4;
 236   return TRUE;
 237 }