1/*
2 * xdr_mem.c, XDR implementation using memory buffers.
3 *
4 * Copyright (c) 2010, Oracle America, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 *
10 * * Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials
15 * provided with the distribution.
16 * * Neither the name of the "Oracle America, Inc." nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 * If you have some data to be interpreted as external data representation
34 * or to be converted to external data representation in a memory buffer,
35 * then this is the package for you.
36 */
37
38#include <string.h>
39#include <limits.h>
40#include <rpc/rpc.h>
41
42static bool_t xdrmem_getlong (XDR *, long *);
43static bool_t xdrmem_putlong (XDR *, const long *);
44static bool_t xdrmem_getbytes (XDR *, caddr_t, u_int);
45static bool_t xdrmem_putbytes (XDR *, const char *, u_int);
46static u_int xdrmem_getpos (const XDR *);
47static bool_t xdrmem_setpos (XDR *, u_int);
48static int32_t *xdrmem_inline (XDR *, u_int);
49static void xdrmem_destroy (XDR *);
50static bool_t xdrmem_getint32 (XDR *, int32_t *);
51static bool_t xdrmem_putint32 (XDR *, const int32_t *);
52
53static const struct xdr_ops xdrmem_ops =
54{
55 xdrmem_getlong,
56 xdrmem_putlong,
57 xdrmem_getbytes,
58 xdrmem_putbytes,
59 xdrmem_getpos,
60 xdrmem_setpos,
61 xdrmem_inline,
62 xdrmem_destroy,
63 xdrmem_getint32,
64 xdrmem_putint32
65};
66
67/*
68 * The procedure xdrmem_create initializes a stream descriptor for a
69 * memory buffer.
70 */
71void
72xdrmem_create (XDR *xdrs, const caddr_t addr, u_int size, enum xdr_op op)
73{
74 xdrs->x_op = op;
75 /* We have to add the const since the `struct xdr_ops' in `struct XDR'
76 is not `const'. */
77 xdrs->x_ops = (struct xdr_ops *) &xdrmem_ops;
78 xdrs->x_private = xdrs->x_base = addr;
79 xdrs->x_handy = size;
80}
81#ifdef EXPORT_RPC_SYMBOLS
82libc_hidden_def (xdrmem_create)
83#else
84libc_hidden_nolink_sunrpc (xdrmem_create, GLIBC_2_0)
85#endif
86
87/*
88 * Nothing needs to be done for the memory case. The argument is clearly
89 * const.
90 */
91
92static void
93xdrmem_destroy (XDR *xdrs)
94{
95}
96
97/*
98 * Gets the next word from the memory referenced by xdrs and places it
99 * in the long pointed to by lp. It then increments the private word to
100 * point at the next element. Neither object pointed to is const
101 */
102static bool_t
103xdrmem_getlong (XDR *xdrs, long *lp)
104{
105 if (xdrs->x_handy < 4)
106 return FALSE;
107 xdrs->x_handy -= 4;
108 *lp = (int32_t) ntohl ((*((int32_t *) (xdrs->x_private))));
109 xdrs->x_private += 4;
110 return TRUE;
111}
112
113/*
114 * Puts the long pointed to by lp in the memory referenced by xdrs. It
115 * then increments the private word to point at the next element. The
116 * long pointed at is const
117 */
118static bool_t
119xdrmem_putlong (XDR *xdrs, const long *lp)
120{
121 if (xdrs->x_handy < 4)
122 return FALSE;
123 xdrs->x_handy -= 4;
124 *(int32_t *) xdrs->x_private = htonl (*lp);
125 xdrs->x_private += 4;
126 return TRUE;
127}
128
129/*
130 * Gets an unaligned number of bytes from the xdrs structure and writes them
131 * to the address passed in addr. Be very careful when calling this routine
132 * as it could leave the xdrs pointing to an unaligned structure which is not
133 * a good idea. None of the things pointed to are const.
134 */
135static bool_t
136xdrmem_getbytes (XDR *xdrs, caddr_t addr, u_int len)
137{
138 if (xdrs->x_handy < len)
139 return FALSE;
140 xdrs->x_handy -= len;
141 memcpy (addr, xdrs->x_private, len);
142 xdrs->x_private += len;
143 return TRUE;
144}
145
146/*
147 * The complementary function to the above. The same warnings apply about
148 * unaligned data. The source address is const.
149 */
150static bool_t
151xdrmem_putbytes (XDR *xdrs, const char *addr, u_int len)
152{
153 if (xdrs->x_handy < len)
154 return FALSE;
155 xdrs->x_handy -= len;
156 memcpy (xdrs->x_private, addr, len);
157 xdrs->x_private += len;
158 return TRUE;
159}
160
161/*
162 * Not sure what this one does. But it clearly doesn't modify the contents
163 * of xdrs. **FIXME** does this not assume u_int == u_long?
164 */
165static u_int
166xdrmem_getpos (const XDR *xdrs)
167{
168 return (u_long) xdrs->x_private - (u_long) xdrs->x_base;
169}
170
171/*
172 * xdrs modified
173 */
174static bool_t
175xdrmem_setpos (XDR *xdrs, u_int pos)
176{
177 caddr_t newaddr = xdrs->x_base + pos;
178 caddr_t lastaddr = xdrs->x_private + xdrs->x_handy;
179 size_t handy = lastaddr - newaddr;
180
181 if (newaddr > lastaddr
182 || newaddr < xdrs->x_base
183 || handy != (u_int) handy)
184 return FALSE;
185
186 xdrs->x_private = newaddr;
187 xdrs->x_handy = (u_int) handy;
188 return TRUE;
189}
190
191/*
192 * xdrs modified
193 */
194static int32_t *
195xdrmem_inline (XDR *xdrs, u_int len)
196{
197 int32_t *buf = 0;
198
199 if (xdrs->x_handy >= len)
200 {
201 xdrs->x_handy -= len;
202 buf = (int32_t *) xdrs->x_private;
203 xdrs->x_private += len;
204 }
205 return buf;
206}
207
208/*
209 * Gets the next word from the memory referenced by xdrs and places it
210 * in the int pointed to by ip. It then increments the private word to
211 * point at the next element. Neither object pointed to is const
212 */
213static bool_t
214xdrmem_getint32 (XDR *xdrs, int32_t *ip)
215{
216 if (xdrs->x_handy < 4)
217 return FALSE;
218 xdrs->x_handy -= 4;
219 *ip = ntohl ((*((int32_t *) (xdrs->x_private))));
220 xdrs->x_private += 4;
221 return TRUE;
222}
223
224/*
225 * Puts the long pointed to by lp in the memory referenced by xdrs. It
226 * then increments the private word to point at the next element. The
227 * long pointed at is const
228 */
229static bool_t
230xdrmem_putint32 (XDR *xdrs, const int32_t *ip)
231{
232 if (xdrs->x_handy < 4)
233 return FALSE;
234 xdrs->x_handy -= 4;
235 *(int32_t *) xdrs->x_private = htonl (*ip);
236 xdrs->x_private += 4;
237 return TRUE;
238}
239