dbus-marshal-byteswap.c
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-marshal-byteswap.c Swap a block of marshaled data
*
* Copyright (C) 2005 Red Hat, Inc.
*
* SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "dbus-marshal-byteswap.h"
#include "dbus-marshal-basic.h"
#include "dbus-signature.h"
static void
byteswap_body_helper (DBusTypeReader *reader,
dbus_bool_t walk_reader_to_end,
int old_byte_order,
int new_byte_order,
unsigned char *p,
unsigned char **new_p)
{
int current_type;
while ((current_type = _dbus_type_reader_get_current_type (reader)) != DBUS_TYPE_INVALID)
{
switch (current_type)
{
case DBUS_TYPE_BYTE:
++p;
break;
case DBUS_TYPE_INT16:
case DBUS_TYPE_UINT16:
{
p = _DBUS_ALIGN_ADDRESS (p, 2);
*((dbus_uint16_t *) (void *) p) =
DBUS_UINT16_SWAP_LE_BE (*((dbus_uint16_t *) (void *) p));
p += 2;
}
break;
case DBUS_TYPE_BOOLEAN:
case DBUS_TYPE_INT32:
case DBUS_TYPE_UINT32:
case DBUS_TYPE_UNIX_FD:
{
p = _DBUS_ALIGN_ADDRESS (p, 4);
*((dbus_uint32_t *) (void *) p) =
DBUS_UINT32_SWAP_LE_BE (*((dbus_uint32_t *) (void *) p));
p += 4;
}
break;
case DBUS_TYPE_INT64:
case DBUS_TYPE_UINT64:
case DBUS_TYPE_DOUBLE:
{
p = _DBUS_ALIGN_ADDRESS (p, 8);
*((dbus_uint64_t *) (void *) p) =
DBUS_UINT64_SWAP_LE_BE (*((dbus_uint64_t *) (void *) p));
p += 8;
}
break;
case DBUS_TYPE_ARRAY:
case DBUS_TYPE_STRING:
case DBUS_TYPE_OBJECT_PATH:
{
dbus_uint32_t array_len;
p = _DBUS_ALIGN_ADDRESS (p, 4);
array_len = _dbus_unpack_uint32 (old_byte_order, p);
*((dbus_uint32_t *) (void *) p) =
DBUS_UINT32_SWAP_LE_BE (*((dbus_uint32_t *) (void *) p));
p += 4;
if (current_type == DBUS_TYPE_ARRAY)
{
int elem_type;
int alignment;
elem_type = _dbus_type_reader_get_element_type (reader);
alignment = _dbus_type_get_alignment (elem_type);
_dbus_assert ((array_len / alignment) < DBUS_MAXIMUM_ARRAY_LENGTH);
p = _DBUS_ALIGN_ADDRESS (p, alignment);
if (dbus_type_is_fixed (elem_type))
{
if (alignment > 1)
_dbus_swap_array (p, array_len / alignment, alignment);
p += array_len;
}
else
{
DBusTypeReader sub;
const unsigned char *array_end;
array_end = p + array_len;
_dbus_type_reader_recurse (reader, &sub);
while (p < array_end)
{
byteswap_body_helper (&sub,
FALSE,
old_byte_order,
new_byte_order,
p, &p);
}
}
}
else
{
_dbus_assert (current_type == DBUS_TYPE_STRING ||
current_type == DBUS_TYPE_OBJECT_PATH);
p += (array_len + 1); /* + 1 for nul */
}
}
break;
case DBUS_TYPE_SIGNATURE:
{
dbus_uint32_t sig_len;
sig_len = *p;
p += (sig_len + 2); /* +2 for len and nul */
}
break;
case DBUS_TYPE_VARIANT:
{
/* 1 byte sig len, sig typecodes, align to
* contained-type-boundary, values.
*/
dbus_uint32_t sig_len;
DBusString sig;
DBusTypeReader sub;
int contained_alignment;
sig_len = *p;
++p;
_dbus_string_init_const_len (&sig, (const char *) p, sig_len);
p += (sig_len + 1); /* 1 for nul */
contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (&sig, 0));
p = _DBUS_ALIGN_ADDRESS (p, contained_alignment);
_dbus_type_reader_init_types_only (&sub, &sig, 0);
byteswap_body_helper (&sub, FALSE, old_byte_order, new_byte_order, p, &p);
}
break;
case DBUS_TYPE_STRUCT:
case DBUS_TYPE_DICT_ENTRY:
{
DBusTypeReader sub;
p = _DBUS_ALIGN_ADDRESS (p, 8);
_dbus_type_reader_recurse (reader, &sub);
byteswap_body_helper (&sub, TRUE, old_byte_order, new_byte_order, p, &p);
}
break;
default:
_dbus_assert_not_reached ("invalid typecode in supposedly-validated signature");
break;
}
if (walk_reader_to_end)
_dbus_type_reader_next (reader);
else
break;
}
if (new_p)
*new_p = p;
}
void
_dbus_marshal_byteswap (const DBusString *signature,
int signature_start,
int old_byte_order,
int new_byte_order,
DBusString *value_str,
int value_pos)
{
DBusTypeReader reader;
_dbus_assert (value_pos >= 0);
_dbus_assert (value_pos <= _dbus_string_get_length (value_str));
if (old_byte_order == new_byte_order)
return;
_dbus_type_reader_init_types_only (&reader,
signature, signature_start);
byteswap_body_helper (&reader, TRUE,
old_byte_order, new_byte_order,
_dbus_string_get_udata_len (value_str, value_pos, 0),
NULL);
}
/* 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:51
TRUE
#define TRUE
Expands to "1".
Definition dbus-macros.h:41
FALSE
#define FALSE
Expands to "0".
Definition dbus-macros.h:44
_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:987
_dbus_type_get_alignment
int _dbus_type_get_alignment(int typecode)
Gets the alignment requirement for the given type; will be 1, 2, 4, or 8.
Definition dbus-marshal-basic.c:1244
_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:760
_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:189
_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:1484
_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:224
_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:820
_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:1053
_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:785
_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:927
DBUS_TYPE_SIGNATURE
#define DBUS_TYPE_SIGNATURE
Type code marking a D-Bus type signature.
Definition dbus-protocol.h:112
DBUS_TYPE_OBJECT_PATH
#define DBUS_TYPE_OBJECT_PATH
Type code marking a D-Bus object path.
Definition dbus-protocol.h:108
DBUS_TYPE_BYTE
#define DBUS_TYPE_BYTE
Type code marking an 8-bit unsigned integer.
Definition dbus-protocol.h:68
DBUS_TYPE_INT16
#define DBUS_TYPE_INT16
Type code marking a 16-bit signed integer.
Definition dbus-protocol.h:76
DBUS_TYPE_VARIANT
#define DBUS_TYPE_VARIANT
Type code marking a D-Bus variant type.
Definition dbus-protocol.h:126
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:205
DBUS_TYPE_INT32
#define DBUS_TYPE_INT32
Type code marking a 32-bit signed integer.
Definition dbus-protocol.h:84
DBUS_TYPE_UNIX_FD
#define DBUS_TYPE_UNIX_FD
Type code marking a unix file descriptor.
Definition dbus-protocol.h:116
DBUS_TYPE_BOOLEAN
#define DBUS_TYPE_BOOLEAN
Type code marking a boolean.
Definition dbus-protocol.h:72
DBUS_TYPE_STRING
#define DBUS_TYPE_STRING
Type code marking a UTF-8 encoded, nul-terminated Unicode string.
Definition dbus-protocol.h:104
DBUS_TYPE_ARRAY
#define DBUS_TYPE_ARRAY
Type code marking a D-Bus array type.
Definition dbus-protocol.h:122
DBUS_TYPE_INVALID
#define DBUS_TYPE_INVALID
Type code that is never equal to a legitimate type code.
Definition dbus-protocol.h:62
DBUS_TYPE_INT64
#define DBUS_TYPE_INT64
Type code marking a 64-bit signed integer.
Definition dbus-protocol.h:92
DBUS_TYPE_DOUBLE
#define DBUS_TYPE_DOUBLE
Type code marking an 8-byte double in IEEE 754 format.
Definition dbus-protocol.h:100
DBUS_TYPE_UINT64
#define DBUS_TYPE_UINT64
Type code marking a 64-bit unsigned integer.
Definition dbus-protocol.h:96
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:145
DBUS_TYPE_UINT16
#define DBUS_TYPE_UINT16
Type code marking a 16-bit unsigned integer.
Definition dbus-protocol.h:80
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:138
DBUS_TYPE_UINT32
#define DBUS_TYPE_UINT32
Type code marking a 32-bit unsigned integer.
Definition dbus-protocol.h:88
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:355
_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
dbus_uint16_t
unsigned short dbus_uint16_t
A 16-bit unsigned integer on all platforms.
Definition dbus-arch-deps.h:48
dbus_uint32_t
unsigned int dbus_uint32_t
A 32-bit unsigned integer on all platforms.
Definition dbus-arch-deps.h:45
dbus_bool_t
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition dbus-types.h:37
dbus_uint64_t
_DBUS_GNUC_EXTENSION typedef unsigned long dbus_uint64_t
A 64-bit unsigned integer.
Definition dbus-arch-deps.h:38
DBusString
Definition dbus-string.h:47
DBusTypeReader
The type reader is an iterator for reading values from a block of values.
Definition dbus-marshal-recursive.h:42