D-Bus: dbus-marshal-byteswap.c Source File

D-Bus 1.14.10

dbus-marshal-byteswap.c
1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* dbus-marshal-byteswap.c Swap a block of marshaled data
3 *
4 * Copyright (C) 2005 Red Hat, Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24#include <config.h>
25#include "dbus-marshal-byteswap.h"
26#include "dbus-marshal-basic.h"
27#include "dbus-signature.h"
28
34static void
35byteswap_body_helper (DBusTypeReader *reader,
36 dbus_bool_t walk_reader_to_end,
37 int old_byte_order,
38 int new_byte_order,
39 unsigned char *p,
40 unsigned char **new_p)
41{
42 int current_type;
43
44 while ((current_type = _dbus_type_reader_get_current_type (reader)) != DBUS_TYPE_INVALID)
45 {
46 switch (current_type)
47 {
48 case DBUS_TYPE_BYTE:
49 ++p;
50 break;
51
52 case DBUS_TYPE_INT16:
53 case DBUS_TYPE_UINT16:
54 {
55 p = _DBUS_ALIGN_ADDRESS (p, 2);
56 *((dbus_uint16_t*)p) = DBUS_UINT16_SWAP_LE_BE (*((dbus_uint16_t*)p));
57 p += 2;
58 }
59 break;
60
61 case DBUS_TYPE_BOOLEAN:
62 case DBUS_TYPE_INT32:
63 case DBUS_TYPE_UINT32:
64 case DBUS_TYPE_UNIX_FD:
65 {
66 p = _DBUS_ALIGN_ADDRESS (p, 4);
67 *((dbus_uint32_t*)p) = DBUS_UINT32_SWAP_LE_BE (*((dbus_uint32_t*)p));
68 p += 4;
69 }
70 break;
71
72 case DBUS_TYPE_INT64:
73 case DBUS_TYPE_UINT64:
74 case DBUS_TYPE_DOUBLE:
75 {
76 p = _DBUS_ALIGN_ADDRESS (p, 8);
77 *((dbus_uint64_t*)p) = DBUS_UINT64_SWAP_LE_BE (*((dbus_uint64_t*)p));
78 p += 8;
79 }
80 break;
81
82 case DBUS_TYPE_ARRAY:
83 case DBUS_TYPE_STRING:
84 case DBUS_TYPE_OBJECT_PATH:
85 {
86 dbus_uint32_t array_len;
87
88 p = _DBUS_ALIGN_ADDRESS (p, 4);
89
90 array_len = _dbus_unpack_uint32 (old_byte_order, p);
91
92 *((dbus_uint32_t*)p) = DBUS_UINT32_SWAP_LE_BE (*((dbus_uint32_t*)p));
93 p += 4;
94
95 if (current_type == DBUS_TYPE_ARRAY)
96 {
97 int elem_type;
98 int alignment;
99
100 elem_type = _dbus_type_reader_get_element_type (reader);
101 alignment = _dbus_type_get_alignment (elem_type);
102
103 _dbus_assert ((array_len / alignment) < DBUS_MAXIMUM_ARRAY_LENGTH);
104
105 p = _DBUS_ALIGN_ADDRESS (p, alignment);
106
107 if (dbus_type_is_fixed (elem_type))
108 {
109 if (alignment > 1)
110 _dbus_swap_array (p, array_len / alignment, alignment);
111 p += array_len;
112 }
113 else
114 {
115 DBusTypeReader sub;
116 const unsigned char *array_end;
117
118 array_end = p + array_len;
119
120 _dbus_type_reader_recurse (reader, &sub);
121
122 while (p < array_end)
123 {
124 byteswap_body_helper (&sub,
125 FALSE,
126 old_byte_order,
127 new_byte_order,
128 p, &p);
129 }
130 }
131 }
132 else
133 {
134 _dbus_assert (current_type == DBUS_TYPE_STRING ||
135 current_type == DBUS_TYPE_OBJECT_PATH);
136
137 p += (array_len + 1); /* + 1 for nul */
138 }
139 }
140 break;
141
142 case DBUS_TYPE_SIGNATURE:
143 {
144 dbus_uint32_t sig_len;
145
146 sig_len = *p;
147
148 p += (sig_len + 2); /* +2 for len and nul */
149 }
150 break;
151
152 case DBUS_TYPE_VARIANT:
153 {
154 /* 1 byte sig len, sig typecodes, align to
155 * contained-type-boundary, values.
156 */
157 dbus_uint32_t sig_len;
158 DBusString sig;
159 DBusTypeReader sub;
160 int contained_alignment;
161
162 sig_len = *p;
163 ++p;
164
165 _dbus_string_init_const_len (&sig, (const char *) p, sig_len);
166
167 p += (sig_len + 1); /* 1 for nul */
168
169 contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (&sig, 0));
170
171 p = _DBUS_ALIGN_ADDRESS (p, contained_alignment);
172
173 _dbus_type_reader_init_types_only (&sub, &sig, 0);
174
175 byteswap_body_helper (&sub, FALSE, old_byte_order, new_byte_order, p, &p);
176 }
177 break;
178
179 case DBUS_TYPE_STRUCT:
180 case DBUS_TYPE_DICT_ENTRY:
181 {
182 DBusTypeReader sub;
183
184 p = _DBUS_ALIGN_ADDRESS (p, 8);
185
186 _dbus_type_reader_recurse (reader, &sub);
187
188 byteswap_body_helper (&sub, TRUE, old_byte_order, new_byte_order, p, &p);
189 }
190 break;
191
192 default:
193 _dbus_assert_not_reached ("invalid typecode in supposedly-validated signature");
194 break;
195 }
196
197 if (walk_reader_to_end)
198 _dbus_type_reader_next (reader);
199 else
200 break;
201 }
202
203 if (new_p)
204 *new_p = p;
205}
206
217void
218_dbus_marshal_byteswap (const DBusString *signature,
219 int signature_start,
220 int old_byte_order,
221 int new_byte_order,
222 DBusString *value_str,
223 int value_pos)
224{
225 DBusTypeReader reader;
226
227 _dbus_assert (value_pos >= 0);
228 _dbus_assert (value_pos <= _dbus_string_get_length (value_str));
229
230 if (old_byte_order == new_byte_order)
231 return;
232
233 _dbus_type_reader_init_types_only (&reader,
234 signature, signature_start);
235
236 byteswap_body_helper (&reader, TRUE,
237 old_byte_order, new_byte_order,
238 _dbus_string_get_udata_len (value_str, value_pos, 0),
239 NULL);
240}
241
244/* Tests in dbus-marshal-byteswap-util.c */
_dbus_assert_not_reached
#define _dbus_assert_not_reached(explanation)
Aborts with an error message if called.
Definition dbus-internals.h:164
_dbus_assert
#define _dbus_assert(condition)
Aborts with an error message if the condition is false.
Definition dbus-internals.h:153
NULL
#define NULL
A null pointer, defined appropriately for C or C++.
Definition dbus-macros.h:49
TRUE
#define TRUE
Expands to "1".
Definition dbus-macros.h:39
FALSE
#define FALSE
Expands to "0".
Definition dbus-macros.h:42
_dbus_type_reader_recurse
void _dbus_type_reader_recurse(DBusTypeReader *reader, DBusTypeReader *sub)
Initialize a new reader pointing to the first type and corresponding value that's a child of the curr...
Definition dbus-marshal-recursive.c:988
_dbus_type_get_alignment
int _dbus_type_get_alignment(int typecode)
Gets the alignment requirement for the given type; will be 1, 4, or 8.
Definition dbus-marshal-basic.c:1236
_dbus_type_reader_init_types_only
void _dbus_type_reader_init_types_only(DBusTypeReader *reader, const DBusString *type_str, int type_pos)
Like _dbus_type_reader_init() but the iteration is over the signature, not over values.
Definition dbus-marshal-recursive.c:761
_dbus_unpack_uint32
dbus_uint32_t _dbus_unpack_uint32(int byte_order, const unsigned char *data)
Unpacks a 32 bit unsigned integer from a data pointer.
Definition dbus-marshal-basic.c:200
_dbus_first_type_in_signature
int _dbus_first_type_in_signature(const DBusString *str, int pos)
Get the first type in the signature.
Definition dbus-marshal-basic.c:1477
_dbus_marshal_byteswap
void _dbus_marshal_byteswap(const DBusString *signature, int signature_start, int old_byte_order, int new_byte_order, DBusString *value_str, int value_pos)
Byteswaps the marshaled data in the given value_str.
Definition dbus-marshal-byteswap.c:218
_dbus_type_reader_get_element_type
int _dbus_type_reader_get_element_type(const DBusTypeReader *reader)
Gets the type of an element of the array the reader is currently pointing to.
Definition dbus-marshal-recursive.c:821
_dbus_type_reader_next
dbus_bool_t _dbus_type_reader_next(DBusTypeReader *reader)
Skip to the next value on this "level".
Definition dbus-marshal-recursive.c:1054
_dbus_type_reader_get_current_type
int _dbus_type_reader_get_current_type(const DBusTypeReader *reader)
Gets the type of the value the reader is currently pointing to; or for a types-only reader gets the t...
Definition dbus-marshal-recursive.c:786
_dbus_swap_array
void _dbus_swap_array(unsigned char *data, int n_elements, int alignment)
Swaps the elements of an array to the opposite byte order.
Definition dbus-marshal-basic.c:937
DBUS_TYPE_SIGNATURE
#define DBUS_TYPE_SIGNATURE
Type code marking a D-Bus type signature.
Definition dbus-protocol.h:110
DBUS_TYPE_OBJECT_PATH
#define DBUS_TYPE_OBJECT_PATH
Type code marking a D-Bus object path.
Definition dbus-protocol.h:106
DBUS_TYPE_BYTE
#define DBUS_TYPE_BYTE
Type code marking an 8-bit unsigned integer.
Definition dbus-protocol.h:66
DBUS_TYPE_INT16
#define DBUS_TYPE_INT16
Type code marking a 16-bit signed integer.
Definition dbus-protocol.h:74
DBUS_TYPE_VARIANT
#define DBUS_TYPE_VARIANT
Type code marking a D-Bus variant type.
Definition dbus-protocol.h:124
DBUS_MAXIMUM_ARRAY_LENGTH
#define DBUS_MAXIMUM_ARRAY_LENGTH
Max length of a marshaled array in bytes (64M, 2^26) We use signed int for lengths so must be INT_MAX...
Definition dbus-protocol.h:203
DBUS_TYPE_INT32
#define DBUS_TYPE_INT32
Type code marking a 32-bit signed integer.
Definition dbus-protocol.h:82
DBUS_TYPE_UNIX_FD
#define DBUS_TYPE_UNIX_FD
Type code marking a unix file descriptor.
Definition dbus-protocol.h:114
DBUS_TYPE_BOOLEAN
#define DBUS_TYPE_BOOLEAN
Type code marking a boolean.
Definition dbus-protocol.h:70
DBUS_TYPE_STRING
#define DBUS_TYPE_STRING
Type code marking a UTF-8 encoded, nul-terminated Unicode string.
Definition dbus-protocol.h:102
DBUS_TYPE_ARRAY
#define DBUS_TYPE_ARRAY
Type code marking a D-Bus array type.
Definition dbus-protocol.h:120
DBUS_TYPE_INVALID
#define DBUS_TYPE_INVALID
Type code that is never equal to a legitimate type code.
Definition dbus-protocol.h:60
DBUS_TYPE_INT64
#define DBUS_TYPE_INT64
Type code marking a 64-bit signed integer.
Definition dbus-protocol.h:90
DBUS_TYPE_DOUBLE
#define DBUS_TYPE_DOUBLE
Type code marking an 8-byte double in IEEE 754 format.
Definition dbus-protocol.h:98
DBUS_TYPE_UINT64
#define DBUS_TYPE_UINT64
Type code marking a 64-bit unsigned integer.
Definition dbus-protocol.h:94
DBUS_TYPE_DICT_ENTRY
#define DBUS_TYPE_DICT_ENTRY
Type code used to represent a dict entry; however, this type code does not appear in type signatures,...
Definition dbus-protocol.h:143
DBUS_TYPE_UINT16
#define DBUS_TYPE_UINT16
Type code marking a 16-bit unsigned integer.
Definition dbus-protocol.h:78
DBUS_TYPE_STRUCT
#define DBUS_TYPE_STRUCT
STRUCT and DICT_ENTRY are sort of special since their codes can't appear in a type string,...
Definition dbus-protocol.h:136
DBUS_TYPE_UINT32
#define DBUS_TYPE_UINT32
Type code marking a 32-bit unsigned integer.
Definition dbus-protocol.h:86
dbus_type_is_fixed
dbus_bool_t dbus_type_is_fixed(int typecode)
Tells you whether values of this type can change length if you set them to some other value.
Definition dbus-signature.c:353
_dbus_string_init_const_len
void _dbus_string_init_const_len(DBusString *str, const char *value, int len)
Initializes a constant string with a length.
Definition dbus-string.c:217
DBusString
Definition dbus-string.h:43
DBusTypeReader
The type reader is an iterator for reading values from a block of values.
Definition dbus-marshal-recursive.h:40