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 INTDEF(xdrmem_create)
  84
  85 /*
  86  * Nothing needs to be done for the memory case.  The argument is clearly
  87  * const.
  88  */
  89
  90 static void
  91 xdrmem_destroy (XDR *xdrs)
  92 {
  93 }
  94
  95 /*
  96  * Gets the next word from the memory referenced by xdrs and places it
  97  * in the long pointed to by lp.  It then increments the private word to
  98  * point at the next element.  Neither object pointed to is const
  99  */
 100 static bool_t
 101 xdrmem_getlong (XDR *xdrs, long *lp)
 102 {
 103   if ((xdrs->x_handy -= 4) < 0)
 104     return FALSE;
 105   *lp = (int32_t) ntohl ((*((int32_t *) (xdrs->x_private))));
 106   xdrs->x_private += 4;
 107   return TRUE;
 108 }
 109
 110 /*
 111  * Puts the long pointed to by lp in the memory referenced by xdrs.  It
 112  * then increments the private word to point at the next element.  The
 113  * long pointed at is const
 114  */
 115 static bool_t
 116 xdrmem_putlong (XDR *xdrs, const long *lp)
 117 {
 118   if ((xdrs->x_handy -= 4) < 0)
 119     return FALSE;
 120   *(int32_t *) xdrs->x_private = htonl (*lp);
 121   xdrs->x_private += 4;
 122   return TRUE;
 123 }
 124
 125 /*
 126  * Gets an unaligned number of bytes from the xdrs structure and writes them
 127  * to the address passed in addr.  Be very careful when calling this routine
 128  * as it could leave the xdrs pointing to an unaligned structure which is not
 129  * a good idea.  None of the things pointed to are const.
 130  */
 131 static bool_t
 132 xdrmem_getbytes (XDR *xdrs, caddr_t addr, u_int len)
 133 {
 134   if ((xdrs->x_handy -= len) < 0)
 135     return FALSE;
 136   memcpy (addr, xdrs->x_private, len);
 137   xdrs->x_private += len;
 138   return TRUE;
 139 }
 140
 141 /*
 142  * The complementary function to the above.  The same warnings apply about
 143  * unaligned data.  The source address is const.
 144  */
 145 static bool_t
 146 xdrmem_putbytes (XDR *xdrs, const char *addr, u_int len)
 147 {
 148   if ((xdrs->x_handy -= len) < 0)
 149     return FALSE;
 150   memcpy (xdrs->x_private, addr, len);
 151   xdrs->x_private += len;
 152   return TRUE;
 153 }
 154
 155 /*
 156  * Not sure what this one does.  But it clearly doesn't modify the contents
 157  * of xdrs.  **FIXME** does this not assume u_int == u_long?
 158  */
 159 static u_int
 160 xdrmem_getpos (const XDR *xdrs)
 161 {
 162   return (u_long) xdrs->x_private - (u_long) xdrs->x_base;
 163 }
 164
 165 /*
 166  * xdrs modified
 167  */
 168 static bool_t
 169 xdrmem_setpos (xdrs, pos)
 170      XDR *xdrs;
 171      u_int pos;
 172 {
 173   caddr_t newaddr = xdrs->x_base + pos;
 174   caddr_t lastaddr = xdrs->x_private + xdrs->x_handy;
 175
 176   if ((long) newaddr > (long) lastaddr)
 177     return FALSE;
 178   xdrs->x_private = newaddr;
 179   xdrs->x_handy = (long) lastaddr - (long) newaddr;
 180   return TRUE;
 181 }
 182
 183 /*
 184  * xdrs modified
 185  */
 186 static int32_t *
 187 xdrmem_inline (XDR *xdrs, int len)
 188 {
 189   int32_t *buf = 0;
 190
 191   if (xdrs->x_handy >= len)
 192     {
 193       xdrs->x_handy -= len;
 194       buf = (int32_t *) xdrs->x_private;
 195       xdrs->x_private += len;
 196     }
 197   return buf;
 198 }
 199
 200 /*
 201  * Gets the next word from the memory referenced by xdrs and places it
 202  * in the int pointed to by ip.  It then increments the private word to
 203  * point at the next element.  Neither object pointed to is const
 204  */
 205 static bool_t
 206 xdrmem_getint32 (XDR *xdrs, int32_t *ip)
 207 {
 208   if ((xdrs->x_handy -= 4) < 0)
 209     return FALSE;
 210   *ip = ntohl ((*((int32_t *) (xdrs->x_private))));
 211   xdrs->x_private += 4;
 212   return TRUE;
 213 }
 214
 215 /*
 216  * Puts the long pointed to by lp in the memory referenced by xdrs.  It
 217  * then increments the private word to point at the next element.  The
 218  * long pointed at is const
 219  */
 220 static bool_t
 221 xdrmem_putint32 (XDR *xdrs, const int32_t *ip)
 222 {
 223   if ((xdrs->x_handy -= 4) < 0)
 224     return FALSE;
 225   *(int32_t *) xdrs->x_private = htonl (*ip);
 226   xdrs->x_private += 4;
 227   return TRUE;
 228 }