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