fdo-mirrors/dbus
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/dbus/dbus.git synced 2026-05-02 10:47:58 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions
dbus/dbus/dbus-marshal-recursive.c
Simon McVittie 26d5d97d5b Don't cast user-supplied pointers to DBusBasicValue * 
If we cast a user-supplied pointer to DBusBasicValue *, that's like
promising that the pointer is to an object at least as strictly aligned
as a DBusBasicValue. In practice, it often isn't: for example, when
we marshal a dbus_uint32_t, a pointer to it is only guaranteed to be
32-bit-aligned, whereas DBusBasicValue typically requires 64-bit
alignment.

Signed-off-by: Simon McVittie <smcv@collabora.com>
2018-12-11 12:23:06 +00:00

2755 lines
94 KiB
C
Raw Blame History

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-marshal-recursive.c Marshalling routines for recursive types
*
* Copyright (C) 2004, 2005 Red Hat, Inc.
*
* 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-recursive.h"
#include "dbus-marshal-basic.h"
#include "dbus-signature.h"
#include "dbus-internals.h"
/**
* @addtogroup DBusMarshal
* @{
*/
static dbus_bool_t _dbus_type_reader_greater_than (const DBusTypeReader *lhs,
const DBusTypeReader *rhs);
static void _dbus_type_writer_set_enabled (DBusTypeWriter *writer,
dbus_bool_t enabled);
static dbus_bool_t _dbus_type_writer_write_reader_partial (DBusTypeWriter *writer,
DBusTypeReader *reader,
const DBusTypeReader *start_after,
int start_after_new_pos,
int start_after_new_len,
DBusList **fixups);
/** turn this on to get deluged in TypeReader verbose spam */
#define RECURSIVE_MARSHAL_READ_TRACE 0
/** turn this on to get deluged in TypeWriter verbose spam */
#define RECURSIVE_MARSHAL_WRITE_TRACE 0
static void
free_fixups (DBusList **fixups)
{
DBusList *link;
link = _dbus_list_get_first_link (fixups);
while (link != NULL)
{
DBusList *next;
next = _dbus_list_get_next_link (fixups, link);
dbus_free (link->data);
_dbus_list_free_link (link);
link = next;
}
*fixups = NULL;
}
static void
apply_and_free_fixups (DBusList **fixups,
DBusTypeReader *reader)
{
DBusList *link;
#if RECURSIVE_MARSHAL_WRITE_TRACE
if (*fixups)
_dbus_verbose (" %d FIXUPS to apply\n",
_dbus_list_get_length (fixups));
#endif
link = _dbus_list_get_first_link (fixups);
while (link != NULL)
{
DBusList *next;
next = _dbus_list_get_next_link (fixups, link);
if (reader)
{
DBusArrayLenFixup *f;
f = link->data;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" applying FIXUP to reader %p at pos %d new_len = %d old len %d\n",
reader, f->len_pos_in_reader, f->new_len,
_dbus_marshal_read_uint32 (reader->value_str,
f->len_pos_in_reader,
reader->byte_order, NULL));
#endif
_dbus_marshal_set_uint32 ((DBusString*) reader->value_str,
f->len_pos_in_reader,
f->new_len,
reader->byte_order);
}
dbus_free (link->data);
_dbus_list_free_link (link);
link = next;
}
*fixups = NULL;
}
/**
* Virtual table for a type reader.
*/
struct DBusTypeReaderClass
{
const char *name; /**< name for debugging */
int id; /**< index in all_reader_classes */
dbus_bool_t types_only; /**< only iterates over types, not values */
void (* recurse) (DBusTypeReader *sub,
DBusTypeReader *parent); /**< recurse with this reader as sub */
dbus_bool_t (* check_finished) (const DBusTypeReader *reader); /**< check whether reader is at the end */
void (* next) (DBusTypeReader *reader,
int current_type); /**< go to the next value */
};
static int
element_type_get_alignment (const DBusString *str,
int pos)
{
return _dbus_type_get_alignment (_dbus_first_type_in_signature (str, pos));
}
static void
reader_init (DBusTypeReader *reader,
int byte_order,
const DBusString *type_str,
int type_pos,
const DBusString *value_str,
int value_pos)
{
_DBUS_ZERO (*reader);
reader->byte_order = byte_order;
reader->finished = FALSE;
reader->type_str = type_str;
reader->type_pos = type_pos;
reader->value_str = value_str;
reader->value_pos = value_pos;
}
static void
base_reader_recurse (DBusTypeReader *sub,
DBusTypeReader *parent)
{
/* point subreader at the same place as parent */
reader_init (sub,
parent->byte_order,
parent->type_str,
parent->type_pos,
parent->value_str,
parent->value_pos);
}
static void
struct_or_dict_entry_types_only_reader_recurse (DBusTypeReader *sub,
DBusTypeReader *parent)
{
base_reader_recurse (sub, parent);
_dbus_assert (_dbus_string_get_byte (sub->type_str,
sub->type_pos) == DBUS_STRUCT_BEGIN_CHAR ||
_dbus_string_get_byte (sub->type_str,
sub->type_pos) == DBUS_DICT_ENTRY_BEGIN_CHAR);
sub->type_pos += 1;
}
static void
struct_or_dict_entry_reader_recurse (DBusTypeReader *sub,
DBusTypeReader *parent)
{
struct_or_dict_entry_types_only_reader_recurse (sub, parent);
/* struct and dict entry have 8 byte alignment */
sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 8);
}
static void
array_types_only_reader_recurse (DBusTypeReader *sub,
DBusTypeReader *parent)
{
base_reader_recurse (sub, parent);
/* point type_pos at the array element type */
sub->type_pos += 1;
/* Init with values likely to crash things if misused */
sub->u.array.start_pos = _DBUS_INT_MAX;
sub->array_len_offset = 7;
}
/** compute position of array length given array_len_offset, which is
the offset back from start_pos to end of the len */
#define ARRAY_READER_LEN_POS(reader) \
((reader)->u.array.start_pos - ((int)(reader)->array_len_offset) - 4)
static int
array_reader_get_array_len (const DBusTypeReader *reader)
{
dbus_uint32_t array_len;
int len_pos;
len_pos = ARRAY_READER_LEN_POS (reader);
_dbus_assert (_DBUS_ALIGN_VALUE (len_pos, 4) == (unsigned) len_pos);
array_len = _dbus_unpack_uint32 (reader->byte_order,
_dbus_string_get_const_udata_len (reader->value_str, len_pos, 4));
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" reader %p len_pos %d array len %u len_offset %d\n",
reader, len_pos, array_len, reader->array_len_offset);
#endif
_dbus_assert (reader->u.array.start_pos - len_pos - 4 < 8);
return array_len;
}
static void
array_reader_recurse (DBusTypeReader *sub,
DBusTypeReader *parent)
{
int alignment;
int len_pos;
array_types_only_reader_recurse (sub, parent);
sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 4);
len_pos = sub->value_pos;
sub->value_pos += 4; /* for the length */
alignment = element_type_get_alignment (sub->type_str,
sub->type_pos);
sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, alignment);
sub->u.array.start_pos = sub->value_pos;
_dbus_assert ((sub->u.array.start_pos - (len_pos + 4)) < 8); /* only 3 bits in array_len_offset */
sub->array_len_offset = sub->u.array.start_pos - (len_pos + 4);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p array start = %d len_offset = %d array len = %d array element type = %s\n",
sub,
sub->u.array.start_pos,
sub->array_len_offset,
array_reader_get_array_len (sub),
_dbus_type_to_string (_dbus_first_type_in_signature (sub->type_str,
sub->type_pos)));
#endif
}
static void
variant_reader_recurse (DBusTypeReader *sub,
DBusTypeReader *parent)
{
int sig_len;
int contained_alignment;
base_reader_recurse (sub, parent);
/* Variant is 1 byte sig length (without nul), signature with nul,
* padding to 8-boundary, then values
*/
sig_len = _dbus_string_get_byte (sub->value_str, sub->value_pos);
sub->type_str = sub->value_str;
sub->type_pos = sub->value_pos + 1;
sub->value_pos = sub->type_pos + sig_len + 1;
contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (sub->type_str,
sub->type_pos));
sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, contained_alignment);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p variant containing '%s'\n",
sub,
_dbus_string_get_const_data_len (sub->type_str,
sub->type_pos, 0));
#endif
}
static dbus_bool_t
array_reader_check_finished (const DBusTypeReader *reader)
{
int end_pos;
/* return the array element type if elements remain, and
* TYPE_INVALID otherwise
*/
end_pos = reader->u.array.start_pos + array_reader_get_array_len (reader);
_dbus_assert (reader->value_pos <= end_pos);
_dbus_assert (reader->value_pos >= reader->u.array.start_pos);
return reader->value_pos == end_pos;
}
static void
skip_one_complete_type (const DBusString *type_str,
int *type_pos)
{
_dbus_type_signature_next (_dbus_string_get_const_data (type_str),
type_pos);
}
/**
* Skips to the next "complete" type inside a type signature.
* The signature is read starting at type_pos, and the next
* type position is stored in the same variable.
*
* @param type_str a type signature (must be valid)
* @param type_pos an integer position in the type signature (in and out)
*/
void
_dbus_type_signature_next (const char *type_str,
int *type_pos)
{
const unsigned char *p;
const unsigned char *start;
_dbus_assert (type_str != NULL);
_dbus_assert (type_pos != NULL);
start = (const unsigned char *)type_str;
p = start + *type_pos;
_dbus_assert (*p != DBUS_STRUCT_END_CHAR);
_dbus_assert (*p != DBUS_DICT_ENTRY_END_CHAR);
while (*p == DBUS_TYPE_ARRAY)
++p;
_dbus_assert (*p != DBUS_STRUCT_END_CHAR);
_dbus_assert (*p != DBUS_DICT_ENTRY_END_CHAR);
if (*p == DBUS_STRUCT_BEGIN_CHAR)
{
int depth;
depth = 1;
while (TRUE)
{
_dbus_assert (*p != DBUS_TYPE_INVALID);
++p;
_dbus_assert (*p != DBUS_TYPE_INVALID);
if (*p == DBUS_STRUCT_BEGIN_CHAR)
depth += 1;
else if (*p == DBUS_STRUCT_END_CHAR)
{
depth -= 1;
if (depth == 0)
{
++p;
break;
}
}
}
}
else if (*p == DBUS_DICT_ENTRY_BEGIN_CHAR)
{
int depth;
depth = 1;
while (TRUE)
{
_dbus_assert (*p != DBUS_TYPE_INVALID);
++p;
_dbus_assert (*p != DBUS_TYPE_INVALID);
if (*p == DBUS_DICT_ENTRY_BEGIN_CHAR)
depth += 1;
else if (*p == DBUS_DICT_ENTRY_END_CHAR)
{
depth -= 1;
if (depth == 0)
{
++p;
break;
}
}
}
}
else
{
++p;
}
*type_pos = (int) (p - start);
}
static int
find_len_of_complete_type (const DBusString *type_str,
int type_pos)
{
int end;
end = type_pos;
skip_one_complete_type (type_str, &end);
return end - type_pos;
}
static void
base_reader_next (DBusTypeReader *reader,
int current_type)
{
switch (current_type)
{
case DBUS_TYPE_DICT_ENTRY:
case DBUS_TYPE_STRUCT:
case DBUS_TYPE_VARIANT:
/* Scan forward over the entire container contents */
{
DBusTypeReader sub;
if (reader->klass->types_only && current_type == DBUS_TYPE_VARIANT)
;
else
{
/* Recurse into the struct or variant */
_dbus_type_reader_recurse (reader, &sub);
/* Skip everything in this subreader */
while (_dbus_type_reader_next (&sub))
{
/* nothing */;
}
}
if (!reader->klass->types_only)
reader->value_pos = sub.value_pos;
/* Now we are at the end of this container; for variants, the
* subreader's type_pos is totally inapplicable (it's in the
* value string) but we know that we increment by one past the
* DBUS_TYPE_VARIANT
*/
if (current_type == DBUS_TYPE_VARIANT)
reader->type_pos += 1;
else
reader->type_pos = sub.type_pos;
}
break;
case DBUS_TYPE_ARRAY:
{
if (!reader->klass->types_only)
_dbus_marshal_skip_array (reader->value_str,
_dbus_first_type_in_signature (reader->type_str,
reader->type_pos + 1),
reader->byte_order,
&reader->value_pos);
skip_one_complete_type (reader->type_str, &reader->type_pos);
}
break;
default:
if (!reader->klass->types_only)
_dbus_marshal_skip_basic (reader->value_str,
current_type, reader->byte_order,
&reader->value_pos);
reader->type_pos += 1;
break;
}
}
static void
struct_reader_next (DBusTypeReader *reader,
int current_type)
{
int t;
base_reader_next (reader, current_type);
/* for STRUCT containers we return FALSE at the end of the struct,
* for INVALID we return FALSE at the end of the signature.
* In both cases we arrange for get_current_type() to return INVALID
* which is defined to happen iff we're at the end (no more next())
*/
t = _dbus_string_get_byte (reader->type_str, reader->type_pos);
if (t == DBUS_STRUCT_END_CHAR)
{
reader->type_pos += 1;
reader->finished = TRUE;
}
}
static void
dict_entry_reader_next (DBusTypeReader *reader,
int current_type)
{
int t;
base_reader_next (reader, current_type);
/* for STRUCT containers we return FALSE at the end of the struct,
* for INVALID we return FALSE at the end of the signature.
* In both cases we arrange for get_current_type() to return INVALID
* which is defined to happen iff we're at the end (no more next())
*/
t = _dbus_string_get_byte (reader->type_str, reader->type_pos);
if (t == DBUS_DICT_ENTRY_END_CHAR)
{
reader->type_pos += 1;
reader->finished = TRUE;
}
}
static void
array_types_only_reader_next (DBusTypeReader *reader,
int current_type)
{
/* We have one "element" to be iterated over
* in each array, which is its element type.
* So the finished flag indicates whether we've
* iterated over it yet or not.
*/
reader->finished = TRUE;
}
static void
array_reader_next (DBusTypeReader *reader,
int current_type)
{
/* Skip one array element */
int end_pos;
end_pos = reader->u.array.start_pos + array_reader_get_array_len (reader);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" reader %p array next START start_pos = %d end_pos = %d value_pos = %d current_type = %s\n",
reader,
reader->u.array.start_pos,
end_pos, reader->value_pos,
_dbus_type_to_string (current_type));
#endif
_dbus_assert (reader->value_pos < end_pos);
_dbus_assert (reader->value_pos >= reader->u.array.start_pos);
switch (_dbus_first_type_in_signature (reader->type_str,
reader->type_pos))
{
case DBUS_TYPE_DICT_ENTRY:
case DBUS_TYPE_STRUCT:
case DBUS_TYPE_VARIANT:
{
DBusTypeReader sub;
/* Recurse into the struct or variant */
_dbus_type_reader_recurse (reader, &sub);
/* Skip everything in this element */
while (_dbus_type_reader_next (&sub))
{
/* nothing */;
}
/* Now we are at the end of this element */
reader->value_pos = sub.value_pos;
}
break;
case DBUS_TYPE_ARRAY:
{
_dbus_marshal_skip_array (reader->value_str,
_dbus_first_type_in_signature (reader->type_str,
reader->type_pos + 1),
reader->byte_order,
&reader->value_pos);
}
break;
default:
{
_dbus_marshal_skip_basic (reader->value_str,
current_type, reader->byte_order,
&reader->value_pos);
}
break;
}
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" reader %p array next END start_pos = %d end_pos = %d value_pos = %d current_type = %s\n",
reader,
reader->u.array.start_pos,
end_pos, reader->value_pos,
_dbus_type_to_string (current_type));
#endif
_dbus_assert (reader->value_pos <= end_pos);
if (reader->value_pos == end_pos)
{
skip_one_complete_type (reader->type_str,
&reader->type_pos);
}
}
static const DBusTypeReaderClass body_reader_class = {
"body", 0,
FALSE,
NULL, /* body is always toplevel, so doesn't get recursed into */
NULL,
base_reader_next
};
static const DBusTypeReaderClass body_types_only_reader_class = {
"body types", 1,
TRUE,
NULL, /* body is always toplevel, so doesn't get recursed into */
NULL,
base_reader_next
};
static const DBusTypeReaderClass struct_reader_class = {
"struct", 2,
FALSE,
struct_or_dict_entry_reader_recurse,
NULL,
struct_reader_next
};
static const DBusTypeReaderClass struct_types_only_reader_class = {
"struct types", 3,
TRUE,
struct_or_dict_entry_types_only_reader_recurse,
NULL,
struct_reader_next
};
static const DBusTypeReaderClass dict_entry_reader_class = {
"dict_entry", 4,
FALSE,
struct_or_dict_entry_reader_recurse,
NULL,
dict_entry_reader_next
};
static const DBusTypeReaderClass dict_entry_types_only_reader_class = {
"dict_entry types", 5,
TRUE,
struct_or_dict_entry_types_only_reader_recurse,
NULL,
dict_entry_reader_next
};
static const DBusTypeReaderClass array_reader_class = {
"array", 6,
FALSE,
array_reader_recurse,
array_reader_check_finished,
array_reader_next
};
static const DBusTypeReaderClass array_types_only_reader_class = {
"array types", 7,
TRUE,
array_types_only_reader_recurse,
NULL,
array_types_only_reader_next
};
static const DBusTypeReaderClass variant_reader_class = {
"variant", 8,
FALSE,
variant_reader_recurse,
NULL,
base_reader_next
};
#ifndef DBUS_DISABLE_ASSERT
static const DBusTypeReaderClass * const
all_reader_classes[] = {
&body_reader_class,
&body_types_only_reader_class,
&struct_reader_class,
&struct_types_only_reader_class,
&dict_entry_reader_class,
&dict_entry_types_only_reader_class,
&array_reader_class,
&array_types_only_reader_class,
&variant_reader_class
};
#endif
/**
* Initializes a type reader.
*
* @param reader the reader
* @param byte_order the byte order of the block to read
* @param type_str the signature of the block to read
* @param type_pos location of signature
* @param value_str the string containing values block
* @param value_pos start of values block
*/
void
_dbus_type_reader_init (DBusTypeReader *reader,
int byte_order,
const DBusString *type_str,
int type_pos,
const DBusString *value_str,
int value_pos)
{
reader_init (reader, byte_order, type_str, type_pos,
value_str, value_pos);
reader->klass = &body_reader_class;
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p init type_pos = %d value_pos = %d remaining sig '%s'\n",
reader, reader->type_pos, reader->value_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
#endif
}
/**
* Like _dbus_type_reader_init() but the iteration is over the
* signature, not over values.
*
* @param reader the reader
* @param type_str the signature string
* @param type_pos location in the signature string
*/
void
_dbus_type_reader_init_types_only (DBusTypeReader *reader,
const DBusString *type_str,
int type_pos)
{
reader_init (reader, DBUS_COMPILER_BYTE_ORDER /* irrelevant */,
type_str, type_pos, NULL, _DBUS_INT_MAX /* crashes if we screw up */);
reader->klass = &body_types_only_reader_class;
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p init types only type_pos = %d remaining sig '%s'\n",
reader, reader->type_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
#endif
}
/**
* Gets the type of the value the reader is currently pointing to;
* or for a types-only reader gets the type it's currently pointing to.
* If the reader is at the end of a block or end of a container such
* as an array, returns #DBUS_TYPE_INVALID.
*
* @param reader the reader
*/
int
_dbus_type_reader_get_current_type (const DBusTypeReader *reader)
{
int t;
if (reader->finished ||
(reader->klass->check_finished &&
(* reader->klass->check_finished) (reader)))
t = DBUS_TYPE_INVALID;
else
t = _dbus_first_type_in_signature (reader->type_str,
reader->type_pos);
_dbus_assert (t != DBUS_STRUCT_END_CHAR);
_dbus_assert (t != DBUS_STRUCT_BEGIN_CHAR);
_dbus_assert (t != DBUS_DICT_ENTRY_END_CHAR);
_dbus_assert (t != DBUS_DICT_ENTRY_BEGIN_CHAR);
#if 0
_dbus_verbose (" type reader %p current type_pos = %d type = %s\n",
reader, reader->type_pos,
_dbus_type_to_string (t));
#endif
return t;
}
/**
* Gets the type of an element of the array the reader is currently
* pointing to. It's an error to call this if
* _dbus_type_reader_get_current_type() doesn't return #DBUS_TYPE_ARRAY
* for this reader.
*
* @param reader the reader
*/
int
_dbus_type_reader_get_element_type (const DBusTypeReader *reader)
{
int element_type;
_dbus_assert (_dbus_type_reader_get_current_type (reader) == DBUS_TYPE_ARRAY);
element_type = _dbus_first_type_in_signature (reader->type_str,
reader->type_pos + 1);
return element_type;
}
/**
* Gets the current position in the value block
* @param reader the reader
*/
int
_dbus_type_reader_get_value_pos (const DBusTypeReader *reader)
{
return reader->value_pos;
}
/**
* Get the address of the marshaled value in the data being read. The
* address may not be aligned; you have to align it to the type of the
* value you want to read. Most of the demarshal routines do this for
* you.
*
* @param reader the reader
* @param value_location the address of the marshaled value
*/
void
_dbus_type_reader_read_raw (const DBusTypeReader *reader,
const unsigned char **value_location)
{
_dbus_assert (!reader->klass->types_only);
*value_location = _dbus_string_get_const_udata_len (reader->value_str,
reader->value_pos,
0);
}
/**
* Reads a basic-typed value, as with _dbus_marshal_read_basic().
*
* @param reader the reader
* @param value the address of the value
*/
void
_dbus_type_reader_read_basic (const DBusTypeReader *reader,
void *value)
{
int t;
_dbus_assert (!reader->klass->types_only);
t = _dbus_type_reader_get_current_type (reader);
_dbus_marshal_read_basic (reader->value_str,
reader->value_pos,
t, value,
reader->byte_order,
NULL);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p read basic type_pos = %d value_pos = %d remaining sig '%s'\n",
reader, reader->type_pos, reader->value_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
#endif
}
/**
* Returns the number of bytes in the array.
*
* @param reader the reader to read from
* @returns the number of bytes in the array
*/
int
_dbus_type_reader_get_array_length (const DBusTypeReader *reader)
{
_dbus_assert (!reader->klass->types_only);
_dbus_assert (reader->klass == &array_reader_class);
return array_reader_get_array_len (reader);
}
/**
* Reads a block of fixed-length basic values, from the current point
* in an array to the end of the array. Does not work for arrays of
* string or container types.
*
* This function returns the array in-place; it does not make a copy,
* and it does not swap the bytes.
*
* If you ask for #DBUS_TYPE_DOUBLE you will get a "const double*" back
* and the "value" argument should be a "const double**" and so on.
*
* @param reader the reader to read from
* @param value place to return the array values
* @param n_elements place to return number of array elements
*/
void
_dbus_type_reader_read_fixed_multi (const DBusTypeReader *reader,
const void **value,
int *n_elements)
{
int element_type;
int end_pos;
int remaining_len;
int alignment;
int total_len;
_dbus_assert (!reader->klass->types_only);
_dbus_assert (reader->klass == &array_reader_class);
element_type = _dbus_first_type_in_signature (reader->type_str,
reader->type_pos);
_dbus_assert (element_type != DBUS_TYPE_INVALID); /* why we don't use get_current_type() */
_dbus_assert (dbus_type_is_fixed (element_type));
alignment = _dbus_type_get_alignment (element_type);
_dbus_assert (reader->value_pos >= reader->u.array.start_pos);
total_len = array_reader_get_array_len (reader);
end_pos = reader->u.array.start_pos + total_len;
remaining_len = end_pos - reader->value_pos;
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose ("end_pos %d total_len %d remaining_len %d value_pos %d\n",
end_pos, total_len, remaining_len, reader->value_pos);
#endif
_dbus_assert (remaining_len <= total_len);
if (remaining_len == 0)
*value = NULL;
else
*value = _dbus_string_get_const_data_len (reader->value_str,
reader->value_pos,
remaining_len);
*n_elements = remaining_len / alignment;
_dbus_assert ((remaining_len % alignment) == 0);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p read fixed array type_pos = %d value_pos = %d remaining sig '%s'\n",
reader, reader->type_pos, reader->value_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
#endif
}
/**
* Initialize a new reader pointing to the first type and
* corresponding value that's a child of the current container. It's
* an error to call this if the current type is a non-container.
*
* Note that DBusTypeReader traverses values, not types. So if you
* have an empty array of array of int, you can't recurse into it. You
* can only recurse into each element.
*
* @param reader the reader
* @param sub a reader to init pointing to the first child
*/
void
_dbus_type_reader_recurse (DBusTypeReader *reader,
DBusTypeReader *sub)
{
int t;
const DBusTypeReaderClass *klass = NULL;
t = _dbus_first_type_in_signature (reader->type_str, reader->type_pos);
switch (t)
{
case DBUS_TYPE_STRUCT:
if (reader->klass->types_only)
klass = &struct_types_only_reader_class;
else
klass = &struct_reader_class;
break;
case DBUS_TYPE_DICT_ENTRY:
if (reader->klass->types_only)
klass = &dict_entry_types_only_reader_class;
else
klass = &dict_entry_reader_class;
break;
case DBUS_TYPE_ARRAY:
if (reader->klass->types_only)
klass = &array_types_only_reader_class;
else
klass = &array_reader_class;
break;
case DBUS_TYPE_VARIANT:
if (reader->klass->types_only)
_dbus_assert_not_reached ("can't recurse into variant typecode");
else
klass = &variant_reader_class;
break;
default:
_dbus_verbose ("recursing into type %s\n", _dbus_type_to_string (t));
#ifndef DBUS_DISABLE_CHECKS
if (t == DBUS_TYPE_INVALID)
_dbus_warn_check_failed ("You can't recurse into an empty array or off the end of a message body");
#endif /* DBUS_DISABLE_CHECKS */
_dbus_assert_not_reached ("don't yet handle recursing into this type");
}
_dbus_assert (klass != NULL);
_dbus_assert (klass == all_reader_classes[klass->id]);
(* klass->recurse) (sub, reader);
sub->klass = klass;
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p RECURSED type_pos = %d value_pos = %d remaining sig '%s'\n",
sub, sub->type_pos, sub->value_pos,
_dbus_string_get_const_data_len (sub->type_str, sub->type_pos, 0));
#endif
}
/**
* Skip to the next value on this "level". e.g. the next field in a
* struct, the next value in an array. Returns FALSE at the end of the
* current container.
*
* @param reader the reader
* @returns FALSE if nothing more to read at or below this level
*/
dbus_bool_t
_dbus_type_reader_next (DBusTypeReader *reader)
{
int t;
t = _dbus_type_reader_get_current_type (reader);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p START next() { type_pos = %d value_pos = %d remaining sig '%s' current_type = %s\n",
reader, reader->type_pos, reader->value_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0),
_dbus_type_to_string (t));
#endif
if (t == DBUS_TYPE_INVALID)
return FALSE;
(* reader->klass->next) (reader, t);
#if RECURSIVE_MARSHAL_READ_TRACE
_dbus_verbose (" type reader %p END next() type_pos = %d value_pos = %d remaining sig '%s' current_type = %s\n",
reader, reader->type_pos, reader->value_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0),
_dbus_type_to_string (_dbus_type_reader_get_current_type (reader)));
#endif
return _dbus_type_reader_get_current_type (reader) != DBUS_TYPE_INVALID;
}
/**
* Check whether there's another value on this "level". e.g. the next
* field in a struct, the next value in an array. Returns FALSE at the
* end of the current container.
*
* You probably don't want to use this; it makes for an awkward for/while
* loop. A nicer one is "while ((current_type = get_current_type()) != INVALID)"
*
* @param reader the reader
* @returns FALSE if nothing more to read at or below this level
*/
dbus_bool_t
_dbus_type_reader_has_next (const DBusTypeReader *reader)
{
/* Not efficient but works for now. */
DBusTypeReader copy;
copy = *reader;
return _dbus_type_reader_next (&copy);
}
/**
* Gets the string and range of said string containing the signature
* of the current value. Essentially a more complete version of
* _dbus_type_reader_get_current_type() (returns the full type
* rather than only the outside of the onion).
*
* Note though that the first byte in a struct signature is
* #DBUS_STRUCT_BEGIN_CHAR while the current type will be
* #DBUS_TYPE_STRUCT so it isn't true that the first byte of the
* signature is always the same as the current type. Another
* difference is that this function will still return a signature when
* inside an empty array; say you recurse into empty array of int32,
* the signature is "i" but the current type will always be
* #DBUS_TYPE_INVALID since there are no elements to be currently
* pointing to.
*
* @param reader the reader
* @param str_p place to return the string with the type in it
* @param start_p place to return start of the type
* @param len_p place to return the length of the type
*/
void
_dbus_type_reader_get_signature (const DBusTypeReader *reader,
const DBusString **str_p,
int *start_p,
int *len_p)
{
*str_p = reader->type_str;
*start_p = reader->type_pos;
*len_p = find_len_of_complete_type (reader->type_str, reader->type_pos);
}
typedef struct
{
DBusString replacement; /**< Marshaled value including alignment padding */
int padding; /**< How much of the replacement block is padding */
} ReplacementBlock;
static dbus_bool_t
replacement_block_init (ReplacementBlock *block,
DBusTypeReader *reader)
{
if (!_dbus_string_init (&block->replacement))
return FALSE;
/* % 8 is the padding to have the same align properties in
* our replacement string as we do at the position being replaced
*/
block->padding = reader->value_pos % 8;
if (!_dbus_string_lengthen (&block->replacement, block->padding))
goto oom;
return TRUE;
oom:
_dbus_string_free (&block->replacement);
return FALSE;
}
static dbus_bool_t
replacement_block_replace (ReplacementBlock *block,
DBusTypeReader *reader,
const DBusTypeReader *realign_root)
{
DBusTypeWriter writer;
DBusTypeReader realign_reader;
DBusList *fixups;
int orig_len;
_dbus_assert (realign_root != NULL);
orig_len = _dbus_string_get_length (&block->replacement);
realign_reader = *realign_root;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("INITIALIZING replacement block writer %p at value_pos %d\n",
&writer, _dbus_string_get_length (&block->replacement));
#endif
_dbus_type_writer_init_values_only (&writer,
realign_reader.byte_order,
realign_reader.type_str,
realign_reader.type_pos,
&block->replacement,
_dbus_string_get_length (&block->replacement));
_dbus_assert (realign_reader.value_pos <= reader->value_pos);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("COPYING from reader at value_pos %d to writer %p starting after value_pos %d\n",
realign_reader.value_pos, &writer, reader->value_pos);
#endif
fixups = NULL;
if (!_dbus_type_writer_write_reader_partial (&writer,
&realign_reader,
reader,
block->padding,
_dbus_string_get_length (&block->replacement) - block->padding,
&fixups))
goto oom;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("REPLACEMENT at padding %d len %d\n", block->padding,
_dbus_string_get_length (&block->replacement) - block->padding);
_dbus_verbose_bytes_of_string (&block->replacement, block->padding,
_dbus_string_get_length (&block->replacement) - block->padding);
_dbus_verbose ("TO BE REPLACED at value_pos = %d (align pad %d) len %d realign_reader.value_pos %d\n",
reader->value_pos, reader->value_pos % 8,
realign_reader.value_pos - reader->value_pos,
realign_reader.value_pos);
_dbus_verbose_bytes_of_string (reader->value_str,
reader->value_pos,
realign_reader.value_pos - reader->value_pos);
#endif
/* Move the replacement into position
* (realign_reader should now be at the end of the block to be replaced)
*/
if (!_dbus_string_replace_len (&block->replacement, block->padding,
_dbus_string_get_length (&block->replacement) - block->padding,
(DBusString*) reader->value_str,
reader->value_pos,
realign_reader.value_pos - reader->value_pos))
goto oom;
/* Process our fixups now that we can't have an OOM error */
apply_and_free_fixups (&fixups, reader);
return TRUE;
oom:
_dbus_string_set_length (&block->replacement, orig_len);
free_fixups (&fixups);
return FALSE;
}
static void
replacement_block_free (ReplacementBlock *block)
{
_dbus_string_free (&block->replacement);
}
/* In the variable-length case, we have to fix alignment after we insert.
* The strategy is as follows:
*
* - pad a new string to have the same alignment as the
* start of the current basic value
* - write the new basic value
* - copy from the original reader to the new string,
* which will fix the alignment of types following
* the new value
* - this copy has to start at realign_root,
* but not really write anything until it
* passes the value being set
* - as an optimization, we can stop copying
* when the source and dest values are both
* on an 8-boundary, since we know all following
* padding and alignment will be identical
* - copy the new string back to the original
* string, replacing the relevant part of the
* original string
* - now any arrays in the original string that
* contained the replaced string may have the
* wrong length; so we have to fix that
*/
static dbus_bool_t
reader_set_basic_variable_length (DBusTypeReader *reader,
int current_type,
const void *value,
const DBusTypeReader *realign_root)
{
dbus_bool_t retval;
ReplacementBlock block;
DBusTypeWriter writer;
_dbus_assert (realign_root != NULL);
retval = FALSE;
if (!replacement_block_init (&block, reader))
return FALSE;
/* Write the new basic value */
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("INITIALIZING writer %p to write basic value at value_pos %d of replacement string\n",
&writer, _dbus_string_get_length (&block.replacement));
#endif
_dbus_type_writer_init_values_only (&writer,
reader->byte_order,
reader->type_str,
reader->type_pos,
&block.replacement,
_dbus_string_get_length (&block.replacement));
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("WRITING basic value to writer %p (replacement string)\n", &writer);
#endif
if (!_dbus_type_writer_write_basic (&writer, current_type, value))
goto out;
if (!replacement_block_replace (&block,
reader,
realign_root))
goto out;
retval = TRUE;
out:
replacement_block_free (&block);
return retval;
}
static void
reader_set_basic_fixed_length (DBusTypeReader *reader,
int current_type,
const void *value)
{
_dbus_marshal_set_basic ((DBusString*) reader->value_str,
reader->value_pos,
current_type,
value,
reader->byte_order,
NULL, NULL);
}
/**
* Sets a new value for the basic type value pointed to by the reader,
* leaving the reader valid to continue reading. Any other readers
* will be invalidated if you set a variable-length type such as a
* string.
*
* The provided realign_root is the reader to start from when
* realigning the data that follows the newly-set value. The reader
* parameter must point to a value below the realign_root parameter.
* If the type being set is fixed-length, then realign_root may be
* #NULL. Only values reachable from realign_root will be realigned,
* so if your string contains other values you will need to deal with
* those somehow yourself. It is OK if realign_root is the same
* reader as the reader parameter, though if you aren't setting the
* root it may not be such a good idea.
*
* @todo DBusTypeReader currently takes "const" versions of the type
* and value strings, and this function modifies those strings by
* casting away the const, which is of course bad if we want to get
* picky. (To be truly clean you'd have an object which contained the
* type and value strings and set_basic would be a method on that
* object... this would also make DBusTypeReader the same thing as
* DBusTypeMark. But since DBusMessage is effectively that object for
* D-Bus it doesn't seem worth creating some random object.)
*
* @todo optimize this by only rewriting until the old and new values
* are at the same alignment. Frequently this should result in only
* replacing the value that's immediately at hand.
*
* @param reader reader indicating where to set a new value
* @param value address of the value to set
* @param realign_root realign from here
* @returns #FALSE if not enough memory
*/
dbus_bool_t
_dbus_type_reader_set_basic (DBusTypeReader *reader,
const void *value,
const DBusTypeReader *realign_root)
{
int current_type;
_dbus_assert (!reader->klass->types_only);
_dbus_assert (reader->value_str == realign_root->value_str);
_dbus_assert (reader->value_pos >= realign_root->value_pos);
current_type = _dbus_type_reader_get_current_type (reader);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" SET BASIC type reader %p type_pos = %d value_pos = %d remaining sig '%s' realign_root = %p with value_pos %d current_type = %s\n",
reader, reader->type_pos, reader->value_pos,
_dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0),
realign_root,
realign_root ? realign_root->value_pos : -1,
_dbus_type_to_string (current_type));
_dbus_verbose_bytes_of_string (realign_root->value_str, realign_root->value_pos,
_dbus_string_get_length (realign_root->value_str) -
realign_root->value_pos);
#endif
_dbus_assert (dbus_type_is_basic (current_type));
if (dbus_type_is_fixed (current_type))
{
reader_set_basic_fixed_length (reader, current_type, value);
return TRUE;
}
else
{
_dbus_assert (realign_root != NULL);
return reader_set_basic_variable_length (reader, current_type,
value, realign_root);
}
}
/**
* Recursively deletes any value pointed to by the reader, leaving the
* reader valid to continue reading. Any other readers will be
* invalidated.
*
* The provided realign_root is the reader to start from when
* realigning the data that follows the newly-set value.
* See _dbus_type_reader_set_basic() for more details on the
* realign_root paramter.
*
* @todo for now this does not delete the typecodes associated with
* the value, so this function should only be used for array elements.
*
* @param reader reader indicating where to delete a value
* @param realign_root realign from here
* @returns #FALSE if not enough memory
*/
dbus_bool_t
_dbus_type_reader_delete (DBusTypeReader *reader,
const DBusTypeReader *realign_root)
{
dbus_bool_t retval;
ReplacementBlock block;
_dbus_assert (realign_root != NULL);
_dbus_assert (reader->klass == &array_reader_class);
retval = FALSE;
if (!replacement_block_init (&block, reader))
return FALSE;
if (!replacement_block_replace (&block,
reader,
realign_root))
goto out;
retval = TRUE;
out:
replacement_block_free (&block);
return retval;
}
/*
* Compares two readers, which must be iterating over the same value data.
* Returns #TRUE if the first parameter is further along than the second parameter.
*
* @param lhs left-hand-side (first) parameter
* @param rhs left-hand-side (first) parameter
* @returns whether lhs is greater than rhs
*/
static dbus_bool_t
_dbus_type_reader_greater_than (const DBusTypeReader *lhs,
const DBusTypeReader *rhs)
{
_dbus_assert (lhs->value_str == rhs->value_str);
return lhs->value_pos > rhs->value_pos;
}
/*
*
*
* DBusTypeWriter
*
*
*
*/
/**
* Initialize a write iterator, which is used to write out values in
* serialized D-Bus format.
*
* The type_pos passed in is expected to be inside an already-valid,
* though potentially empty, type signature. This means that the byte
* after type_pos must be either #DBUS_TYPE_INVALID (aka nul) or some
* other valid type. #DBusTypeWriter won't enforce that the signature
* is already valid (you can append the nul byte at the end if you
* like), but just be aware that you need the nul byte eventually and
* #DBusTypeWriter isn't going to write it for you.
*
* @param writer the writer to init
* @param byte_order the byte order to marshal into
* @param type_str the string to write typecodes into
* @param type_pos where to insert typecodes
* @param value_str the string to write values into
* @param value_pos where to insert values
*
*/
void
_dbus_type_writer_init (DBusTypeWriter *writer,
int byte_order,
DBusString *type_str,
int type_pos,
DBusString *value_str,
int value_pos)
{
writer->byte_order = byte_order;
writer->type_str = type_str;
writer->type_pos = type_pos;
writer->value_str = value_str;
writer->value_pos = value_pos;
writer->container_type = DBUS_TYPE_INVALID;
writer->type_pos_is_expectation = FALSE;
writer->enabled = TRUE;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("writer %p init remaining sig '%s'\n", writer,
writer->type_str ?
_dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
"unknown");
#endif
}
/**
* Initialize a write iterator, with the signature to be provided
* later.
*
* @param writer the writer to init
* @param byte_order the byte order to marshal into
* @param value_str the string to write values into
* @param value_pos where to insert values
*
*/
void
_dbus_type_writer_init_types_delayed (DBusTypeWriter *writer,
int byte_order,
DBusString *value_str,
int value_pos)
{
_dbus_type_writer_init (writer, byte_order,
NULL, 0, value_str, value_pos);
}
/**
* Adds type string to the writer, if it had none.
*
* @param writer the writer to init
* @param type_str type string to add
* @param type_pos type position
*
*/
void
_dbus_type_writer_add_types (DBusTypeWriter *writer,
DBusString *type_str,
int type_pos)
{
if (writer->type_str == NULL) /* keeps us from using this as setter */
{
writer->type_str = type_str;
writer->type_pos = type_pos;
}
}
/**
* Removes type string from the writer.
*
* @param writer the writer to remove from
*/
void
_dbus_type_writer_remove_types (DBusTypeWriter *writer)
{
writer->type_str = NULL;
writer->type_pos = -1;
}
/**
* Like _dbus_type_writer_init(), except the type string
* passed in should correspond to an existing signature that
* matches what you're going to write out. The writer will
* check what you write vs. this existing signature.
*
* @param writer the writer to init
* @param byte_order the byte order to marshal into
* @param type_str the string with signature
* @param type_pos start of signature
* @param value_str the string to write values into
* @param value_pos where to insert values
*
*/
void
_dbus_type_writer_init_values_only (DBusTypeWriter *writer,
int byte_order,
const DBusString *type_str,
int type_pos,
DBusString *value_str,
int value_pos)
{
_dbus_type_writer_init (writer, byte_order,
(DBusString*)type_str, type_pos,
value_str, value_pos);
writer->type_pos_is_expectation = TRUE;
}
static dbus_bool_t
_dbus_type_writer_write_basic_no_typecode (DBusTypeWriter *writer,
int type,
const void *value)
{
if (writer->enabled)
return _dbus_marshal_write_basic (writer->value_str,
writer->value_pos,
type,
value,
writer->byte_order,
&writer->value_pos);
else
return TRUE;
}
/* If our parent is an array, things are a little bit complicated.
*
* The parent must have a complete element type, such as
* "i" or "aai" or "(ii)" or "a(ii)". There can't be
* unclosed parens, or an "a" with no following type.
*
* To recurse, the only allowed operation is to recurse into the
* first type in the element type. So for "i" you can't recurse, for
* "ai" you can recurse into the array, for "(ii)" you can recurse
* into the struct.
*
* If you recurse into the array for "ai", then you must specify
* "i" for the element type of the array you recurse into.
*
* While inside an array at any level, we need to avoid writing to
* type_str, since the type only appears once for the whole array,
* it does not appear for each array element.
*
* While inside an array type_pos points to the expected next
* typecode, rather than the next place we could write a typecode.
*/
static void
writer_recurse_init_and_check (DBusTypeWriter *writer,
int container_type,
DBusTypeWriter *sub)
{
_dbus_type_writer_init (sub,
writer->byte_order,
writer->type_str,
writer->type_pos,
writer->value_str,
writer->value_pos);
sub->container_type = container_type;
if (writer->type_pos_is_expectation ||
(sub->container_type == DBUS_TYPE_ARRAY || sub->container_type == DBUS_TYPE_VARIANT))
sub->type_pos_is_expectation = TRUE;
else
sub->type_pos_is_expectation = FALSE;
sub->enabled = writer->enabled;
#ifndef DBUS_DISABLE_CHECKS
if (writer->type_pos_is_expectation && writer->type_str)
{
int expected;
expected = _dbus_first_type_in_signature (writer->type_str, writer->type_pos);
if (expected != sub->container_type)
{
if (expected != DBUS_TYPE_INVALID)
_dbus_warn_check_failed ("Writing an element of type %s, but the expected type here is %s\n"
"The overall signature expected here was '%s' and we are on byte %d of that signature.",
_dbus_type_to_string (sub->container_type),
_dbus_type_to_string (expected),
_dbus_string_get_const_data (writer->type_str), writer->type_pos);
else
_dbus_warn_check_failed ("Writing an element of type %s, but no value is expected here\n"
"The overall signature expected here was '%s' and we are on byte %d of that signature.",
_dbus_type_to_string (sub->container_type),
_dbus_string_get_const_data (writer->type_str), writer->type_pos);
_dbus_assert_not_reached ("bad array element or variant content written");
}
}
#endif /* DBUS_DISABLE_CHECKS */
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p recurse parent %s type_pos = %d value_pos = %d is_expectation = %d remaining sig '%s' enabled = %d\n",
writer,
_dbus_type_to_string (writer->container_type),
writer->type_pos, writer->value_pos, writer->type_pos_is_expectation,
writer->type_str ?
_dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
"unknown",
writer->enabled);
_dbus_verbose (" type writer %p recurse sub %s type_pos = %d value_pos = %d is_expectation = %d enabled = %d\n",
sub,
_dbus_type_to_string (sub->container_type),
sub->type_pos, sub->value_pos,
sub->type_pos_is_expectation,
sub->enabled);
#endif
}
static dbus_bool_t
write_or_verify_typecode (DBusTypeWriter *writer,
int typecode)
{
/* A subwriter inside an array or variant will have type_pos
* pointing to the expected typecode; a writer not inside an array
* or variant has type_pos pointing to the next place to insert a
* typecode.
*/
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p write_or_verify start type_pos = %d remaining sig '%s' enabled = %d\n",
writer, writer->type_pos,
writer->type_str ?
_dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
"unknown",
writer->enabled);
#endif
if (writer->type_str == NULL)
return TRUE;
if (writer->type_pos_is_expectation)
{
#ifndef DBUS_DISABLE_CHECKS
{
int expected;
expected = _dbus_string_get_byte (writer->type_str, writer->type_pos);
if (expected != typecode)
{
if (expected != DBUS_TYPE_INVALID)
_dbus_warn_check_failed ("Array or variant type requires that type %s be written, but %s was written.\n"
"The overall signature expected here was '%s' and we are on byte %d of that signature.",
_dbus_type_to_string (expected), _dbus_type_to_string (typecode),
_dbus_string_get_const_data (writer->type_str), writer->type_pos);
else
_dbus_warn_check_failed ("Array or variant type wasn't expecting any more values to be written into it, but a value %s was written.\n"
"The overall signature expected here was '%s' and we are on byte %d of that signature.",
_dbus_type_to_string (typecode),
_dbus_string_get_const_data (writer->type_str), writer->type_pos);
_dbus_assert_not_reached ("bad type inserted somewhere inside an array or variant");
}
}
#endif /* DBUS_DISABLE_CHECKS */
/* if immediately inside an array we'd always be appending an element,
* so the expected type doesn't change; if inside a struct or something
* below an array, we need to move through said struct or something.
*/
if (writer->container_type != DBUS_TYPE_ARRAY)
writer->type_pos += 1;
}
else
{
if (!_dbus_string_insert_byte (writer->type_str,
writer->type_pos,
typecode))
return FALSE;
writer->type_pos += 1;
}
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p write_or_verify end type_pos = %d remaining sig '%s'\n",
writer, writer->type_pos,
_dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0));
#endif
return TRUE;
}
static dbus_bool_t
writer_recurse_struct_or_dict_entry (DBusTypeWriter *writer,
int begin_char,
const DBusString *contained_type,
int contained_type_start,
int contained_type_len,
DBusTypeWriter *sub)
{
/* FIXME right now contained_type is ignored; we could probably
* almost trivially fix the code so if it's present we
* write it out and then set type_pos_is_expectation
*/
/* Ensure that we'll be able to add alignment padding and the typecode */
if (writer->enabled)
{
if (!_dbus_string_alloc_space (sub->value_str, 8))
return FALSE;
}
if (!write_or_verify_typecode (sub, begin_char))
_dbus_assert_not_reached ("failed to insert struct typecode after prealloc");
if (writer->enabled)
{
if (!_dbus_string_insert_bytes (sub->value_str,
sub->value_pos,
_DBUS_ALIGN_VALUE (sub->value_pos, 8) - sub->value_pos,
'\0'))
_dbus_assert_not_reached ("should not have failed to insert alignment padding for struct");
sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 8);
}
return TRUE;
}
static dbus_bool_t
writer_recurse_array (DBusTypeWriter *writer,
const DBusString *contained_type,
int contained_type_start,
int contained_type_len,
DBusTypeWriter *sub,
dbus_bool_t is_array_append)
{
dbus_uint32_t value = 0;
int alignment;
int aligned;
#ifndef DBUS_DISABLE_CHECKS
if (writer->container_type == DBUS_TYPE_ARRAY &&
writer->type_str)
{
if (!_dbus_string_equal_substring (contained_type,
contained_type_start,
contained_type_len,
writer->type_str,
writer->u.array.element_type_pos + 1))
{
_dbus_warn_check_failed ("Writing an array of '%s' but this is incompatible with the expected type of elements in the parent array",
_dbus_string_get_const_data_len (contained_type,
contained_type_start,
contained_type_len));
_dbus_assert_not_reached ("incompatible type for child array");
}
}
#endif /* DBUS_DISABLE_CHECKS */
if (writer->enabled && !is_array_append)
{
/* 3 pad + 4 bytes for the array length, and 4 bytes possible padding
* before array values
*/
if (!_dbus_string_alloc_space (sub->value_str, 3 + 4 + 4))
return FALSE;
}
if (writer->type_str != NULL)
{
sub->type_pos += 1; /* move to point to the element type, since type_pos
* should be the expected type for further writes
*/
sub->u.array.element_type_pos = sub->type_pos;
}
if (!writer->type_pos_is_expectation)
{
/* sub is a toplevel/outermost array so we need to write the type data */
/* alloc space for array typecode, element signature */
if (!_dbus_string_alloc_space (writer->type_str, 1 + contained_type_len))
return FALSE;
if (!_dbus_string_insert_byte (writer->type_str,
writer->type_pos,
DBUS_TYPE_ARRAY))
_dbus_assert_not_reached ("failed to insert array typecode after prealloc");
if (!_dbus_string_copy_len (contained_type,
contained_type_start, contained_type_len,
sub->type_str,
sub->u.array.element_type_pos))
_dbus_assert_not_reached ("should not have failed to insert array element typecodes");
}
if (writer->type_str != NULL)
{
/* If the parent is an array, we hold type_pos pointing at the array element type;
* otherwise advance it to reflect the array value we just recursed into
*/
if (writer->container_type != DBUS_TYPE_ARRAY)
writer->type_pos += 1 + contained_type_len;
else
_dbus_assert (writer->type_pos_is_expectation); /* because it's an array */
}
if (writer->enabled)
{
/* Write (or jump over, if is_array_append) the length */
sub->u.array.len_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 4);
if (is_array_append)
{
sub->value_pos += 4;
}
else
{
if (!_dbus_type_writer_write_basic_no_typecode (sub, DBUS_TYPE_UINT32,
&value))
_dbus_assert_not_reached ("should not have failed to insert array len");
}
_dbus_assert (sub->u.array.len_pos == sub->value_pos - 4);
/* Write alignment padding for array elements
* Note that we write the padding *even for empty arrays*
* to avoid wonky special cases
*/
alignment = element_type_get_alignment (contained_type, contained_type_start);
aligned = _DBUS_ALIGN_VALUE (sub->value_pos, alignment);
if (aligned != sub->value_pos)
{
if (!is_array_append)
{
if (!_dbus_string_insert_bytes (sub->value_str,
sub->value_pos,
aligned - sub->value_pos,
'\0'))
_dbus_assert_not_reached ("should not have failed to insert alignment padding");
}
sub->value_pos = aligned;
}
sub->u.array.start_pos = sub->value_pos;
if (is_array_append)
{
dbus_uint32_t len;
_dbus_assert (_DBUS_ALIGN_VALUE (sub->u.array.len_pos, 4) ==
(unsigned) sub->u.array.len_pos);
len = _dbus_unpack_uint32 (sub->byte_order,
_dbus_string_get_const_udata_len (sub->value_str,
sub->u.array.len_pos,
4));
sub->value_pos += len;
}
}
else
{
/* not enabled, so we won't write the len_pos; set it to -1 to so indicate */
sub->u.array.len_pos = -1;
sub->u.array.start_pos = sub->value_pos;
}
_dbus_assert (sub->u.array.len_pos < sub->u.array.start_pos);
_dbus_assert (is_array_append || sub->u.array.start_pos == sub->value_pos);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p recurse array done remaining sig '%s' array start_pos = %d len_pos = %d value_pos = %d\n", sub,
sub->type_str ?
_dbus_string_get_const_data_len (sub->type_str, sub->type_pos, 0) :
"unknown",
sub->u.array.start_pos, sub->u.array.len_pos, sub->value_pos);
#endif
return TRUE;
}
/* Variant value will normally have:
* 1 byte signature length not including nul
* signature typecodes (nul terminated)
* padding to alignment of contained type
* body according to signature
*
* The signature string can only have a single type
* in it but that type may be complex/recursive.
*
* So a typical variant type with the integer 3 will have these
* octets:
* 0x1 'i' '\0' [1 byte padding to alignment boundary] 0x0 0x0 0x0 0x3
*
* The main world of hurt for writing out a variant is that the type
* string is the same string as the value string. Which means
* inserting to the type string will move the value_pos; and it means
* that inserting to the type string could break type alignment.
*/
static dbus_bool_t
writer_recurse_variant (DBusTypeWriter *writer,
const DBusString *contained_type,
int contained_type_start,
int contained_type_len,
DBusTypeWriter *sub)
{
int contained_alignment;
if (writer->enabled)
{
/* Allocate space for the worst case, which is 1 byte sig
* length, nul byte at end of sig, and 7 bytes padding to
* 8-boundary.
*/
if (!_dbus_string_alloc_space (sub->value_str, contained_type_len + 9))
return FALSE;
}
/* write VARIANT typecode to the parent's type string */
if (!write_or_verify_typecode (writer, DBUS_TYPE_VARIANT))
return FALSE;
/* If not enabled, mark that we have no type_str anymore ... */
if (!writer->enabled)
{
sub->type_str = NULL;
sub->type_pos = -1;
return TRUE;
}
/* If we're enabled then continue ... */
if (!_dbus_string_insert_byte (sub->value_str,
sub->value_pos,
contained_type_len))
_dbus_assert_not_reached ("should not have failed to insert variant type sig len");
sub->value_pos += 1;
/* Here we switch over to the expected type sig we're about to write */
sub->type_str = sub->value_str;
sub->type_pos = sub->value_pos;
if (!_dbus_string_copy_len (contained_type, contained_type_start, contained_type_len,
sub->value_str, sub->value_pos))
_dbus_assert_not_reached ("should not have failed to insert variant type sig");
sub->value_pos += contained_type_len;
if (!_dbus_string_insert_byte (sub->value_str,
sub->value_pos,
DBUS_TYPE_INVALID))
_dbus_assert_not_reached ("should not have failed to insert variant type nul termination");
sub->value_pos += 1;
contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (contained_type, contained_type_start));
if (!_dbus_string_insert_bytes (sub->value_str,
sub->value_pos,
_DBUS_ALIGN_VALUE (sub->value_pos, contained_alignment) - sub->value_pos,
'\0'))
_dbus_assert_not_reached ("should not have failed to insert alignment padding for variant body");
sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, contained_alignment);
return TRUE;
}
static dbus_bool_t
_dbus_type_writer_recurse_contained_len (DBusTypeWriter *writer,
int container_type,
const DBusString *contained_type,
int contained_type_start,
int contained_type_len,
DBusTypeWriter *sub,
dbus_bool_t is_array_append)
{
writer_recurse_init_and_check (writer, container_type, sub);
switch (container_type)
{
case DBUS_TYPE_STRUCT:
return writer_recurse_struct_or_dict_entry (writer,
DBUS_STRUCT_BEGIN_CHAR,
contained_type,
contained_type_start, contained_type_len,
sub);
break;
case DBUS_TYPE_DICT_ENTRY:
return writer_recurse_struct_or_dict_entry (writer,
DBUS_DICT_ENTRY_BEGIN_CHAR,
contained_type,
contained_type_start, contained_type_len,
sub);
break;
case DBUS_TYPE_ARRAY:
return writer_recurse_array (writer,
contained_type, contained_type_start, contained_type_len,
sub, is_array_append);
break;
case DBUS_TYPE_VARIANT:
return writer_recurse_variant (writer,
contained_type, contained_type_start, contained_type_len,
sub);
break;
default:
_dbus_assert_not_reached ("tried to recurse into type that doesn't support that");
return FALSE;
break;
}
}
/**
* Opens a new container and writes out the initial information for that container.
*
* @param writer the writer
* @param container_type the type of the container to open
* @param contained_type the array element type or variant content type
* @param contained_type_start position to look for the type
* @param sub the new sub-writer to write container contents
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_type_writer_recurse (DBusTypeWriter *writer,
int container_type,
const DBusString *contained_type,
int contained_type_start,
DBusTypeWriter *sub)
{
int contained_type_len;
if (contained_type)
contained_type_len = find_len_of_complete_type (contained_type, contained_type_start);
else
contained_type_len = 0;
return _dbus_type_writer_recurse_contained_len (writer, container_type,
contained_type,
contained_type_start,
contained_type_len,
sub,
FALSE);
}
/**
* Append to an existing array. Essentially, the writer will read an
* existing length at the write location; jump over that length; and
* write new fields. On unrecurse(), the existing length will be
* updated.
*
* @param writer the writer
* @param contained_type element type
* @param contained_type_start position of element type
* @param sub the subwriter to init
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_type_writer_append_array (DBusTypeWriter *writer,
const DBusString *contained_type,
int contained_type_start,
DBusTypeWriter *sub)
{
int contained_type_len;
if (contained_type)
contained_type_len = find_len_of_complete_type (contained_type, contained_type_start);
else
contained_type_len = 0;
return _dbus_type_writer_recurse_contained_len (writer, DBUS_TYPE_ARRAY,
contained_type,
contained_type_start,
contained_type_len,
sub,
TRUE);
}
static int
writer_get_array_len (DBusTypeWriter *writer)
{
_dbus_assert (writer->container_type == DBUS_TYPE_ARRAY);
return writer->value_pos - writer->u.array.start_pos;
}
/**
* Closes a container created by _dbus_type_writer_recurse()
* and writes any additional information to the values block.
*
* @param writer the writer
* @param sub the sub-writer created by _dbus_type_writer_recurse()
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_type_writer_unrecurse (DBusTypeWriter *writer,
DBusTypeWriter *sub)
{
/* type_pos_is_expectation never gets unset once set, or we'd get all hosed */
_dbus_assert (!writer->type_pos_is_expectation ||
(writer->type_pos_is_expectation && sub->type_pos_is_expectation));
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p unrecurse type_pos = %d value_pos = %d is_expectation = %d container_type = %s\n",
writer, writer->type_pos, writer->value_pos, writer->type_pos_is_expectation,
_dbus_type_to_string (writer->container_type));
_dbus_verbose (" type writer %p unrecurse sub type_pos = %d value_pos = %d is_expectation = %d container_type = %s\n",
sub, sub->type_pos, sub->value_pos,
sub->type_pos_is_expectation,
_dbus_type_to_string (sub->container_type));
#endif
if (sub->container_type == DBUS_TYPE_STRUCT)
{
if (!write_or_verify_typecode (sub, DBUS_STRUCT_END_CHAR))
return FALSE;
}
else if (sub->container_type == DBUS_TYPE_DICT_ENTRY)
{
if (!write_or_verify_typecode (sub, DBUS_DICT_ENTRY_END_CHAR))
return FALSE;
}
else if (sub->container_type == DBUS_TYPE_ARRAY)
{
if (sub->u.array.len_pos >= 0) /* len_pos == -1 if we weren't enabled when we passed it */
{
dbus_uint32_t len;
/* Set the array length */
len = writer_get_array_len (sub);
_dbus_marshal_set_uint32 (sub->value_str,
sub->u.array.len_pos,
len,
sub->byte_order);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" filled in sub array len to %u at len_pos %d\n",
len, sub->u.array.len_pos);
#endif
}
#if RECURSIVE_MARSHAL_WRITE_TRACE
else
{
_dbus_verbose (" not filling in sub array len because we were disabled when we passed the len\n");
}
#endif
}
/* Now get type_pos right for the parent writer. Here are the cases:
*
* Cases !writer->type_pos_is_expectation:
* (in these cases we want to update to the new insertion point)
*
* - if we recursed into a STRUCT then we didn't know in advance
* what the types in the struct would be; so we have to fill in
* that information now.
* writer->type_pos = sub->type_pos
*
* - if we recursed into anything else, we knew the full array
* type, or knew the single typecode marking VARIANT, so
* writer->type_pos is already correct.
* writer->type_pos should remain as-is
*
* - note that the parent is never an ARRAY or VARIANT, if it were
* then type_pos_is_expectation would be TRUE. The parent
* is thus known to be a toplevel or STRUCT.
*
* Cases where writer->type_pos_is_expectation:
* (in these cases we want to update to next expected type to write)
*
* - we recursed from STRUCT into STRUCT and we didn't increment
* type_pos in the parent just to stay consistent with the
* !writer->type_pos_is_expectation case (though we could
* special-case this in recurse_struct instead if we wanted)
* writer->type_pos = sub->type_pos
*
* - we recursed from STRUCT into ARRAY or VARIANT and type_pos
* for parent should have been incremented already
* writer->type_pos should remain as-is
*
* - we recursed from ARRAY into a sub-element, so type_pos in the
* parent is the element type and should remain the element type
* for the benefit of the next child element
* writer->type_pos should remain as-is
*
* - we recursed from VARIANT into its value, so type_pos in the
* parent makes no difference since there's only one value
* and we just finished writing it and won't use type_pos again
* writer->type_pos should remain as-is
*
*
* For all these, DICT_ENTRY is the same as STRUCT
*/
if (writer->type_str != NULL)
{
if ((sub->container_type == DBUS_TYPE_STRUCT ||
sub->container_type == DBUS_TYPE_DICT_ENTRY) &&
(writer->container_type == DBUS_TYPE_STRUCT ||
writer->container_type == DBUS_TYPE_DICT_ENTRY ||
writer->container_type == DBUS_TYPE_INVALID))
{
/* Advance the parent to the next struct field */
writer->type_pos = sub->type_pos;
}
}
writer->value_pos = sub->value_pos;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p unrecursed type_pos = %d value_pos = %d remaining sig '%s'\n",
writer, writer->type_pos, writer->value_pos,
writer->type_str ?
_dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
"unknown");
#endif
return TRUE;
}
/**
* Writes out a basic type.
*
* @param writer the writer
* @param type the type to write
* @param value the address of the value to write
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_type_writer_write_basic (DBusTypeWriter *writer,
int type,
const void *value)
{
dbus_bool_t retval;
/* First ensure that our type realloc will succeed */
if (!writer->type_pos_is_expectation && writer->type_str != NULL)
{
if (!_dbus_string_alloc_space (writer->type_str, 1))
return FALSE;
}
retval = FALSE;
if (!_dbus_type_writer_write_basic_no_typecode (writer, type, value))
goto out;
if (!write_or_verify_typecode (writer, type))
_dbus_assert_not_reached ("failed to write typecode after prealloc");
retval = TRUE;
out:
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p basic type_pos = %d value_pos = %d is_expectation = %d enabled = %d\n",
writer, writer->type_pos, writer->value_pos, writer->type_pos_is_expectation,
writer->enabled);
#endif
return retval;
}
/**
* Writes a block of fixed-length basic values, i.e. those that are
* both dbus_type_is_fixed() and _dbus_type_is_basic(). The block
* must be written inside an array.
*
* The value parameter should be the address of said array of values,
* so e.g. if it's an array of double, pass in "const double**"
*
* @param writer the writer
* @param element_type type of stuff in the array
* @param value address of the array
* @param n_elements number of elements in the array
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_type_writer_write_fixed_multi (DBusTypeWriter *writer,
int element_type,
const void *value,
int n_elements)
{
_dbus_assert (writer->container_type == DBUS_TYPE_ARRAY);
_dbus_assert (dbus_type_is_fixed (element_type));
_dbus_assert (writer->type_pos_is_expectation);
_dbus_assert (n_elements >= 0);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p entering fixed multi type_pos = %d value_pos = %d n_elements %d\n",
writer, writer->type_pos, writer->value_pos, n_elements);
#endif
if (!write_or_verify_typecode (writer, element_type))
_dbus_assert_not_reached ("OOM should not happen if only verifying typecode");
if (writer->enabled)
{
if (!_dbus_marshal_write_fixed_multi (writer->value_str,
writer->value_pos,
element_type,
value,
n_elements,
writer->byte_order,
&writer->value_pos))
return FALSE;
}
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose (" type writer %p fixed multi written new type_pos = %d new value_pos = %d n_elements %d\n",
writer, writer->type_pos, writer->value_pos, n_elements);
#endif
return TRUE;
}
static void
enable_if_after (DBusTypeWriter *writer,
DBusTypeReader *reader,
const DBusTypeReader *start_after)
{
if (start_after)
{
if (!writer->enabled && _dbus_type_reader_greater_than (reader, start_after))
{
_dbus_type_writer_set_enabled (writer, TRUE);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("ENABLING writer %p at %d because reader at value_pos %d is after reader at value_pos %d\n",
writer, writer->value_pos, reader->value_pos, start_after->value_pos);
#endif
}
_dbus_assert ((!writer->enabled && !_dbus_type_reader_greater_than (reader, start_after)) ||
(writer->enabled && _dbus_type_reader_greater_than (reader, start_after)));
}
}
static dbus_bool_t
append_fixup (DBusList **fixups,
const DBusArrayLenFixup *fixup)
{
DBusArrayLenFixup *f;
f = dbus_new (DBusArrayLenFixup, 1);
if (f == NULL)
return FALSE;
*f = *fixup;
if (!_dbus_list_append (fixups, f))
{
dbus_free (f);
return FALSE;
}
_dbus_assert (f->len_pos_in_reader == fixup->len_pos_in_reader);
_dbus_assert (f->new_len == fixup->new_len);
return TRUE;
}
/* This loop is trivial if you ignore all the start_after nonsense,
* so if you're trying to figure it out, start by ignoring that
*/
static dbus_bool_t
writer_write_reader_helper (DBusTypeWriter *writer,
DBusTypeReader *reader,
const DBusTypeReader *start_after,
int start_after_new_pos,
int start_after_new_len,
DBusList **fixups,
dbus_bool_t inside_start_after)
{
int current_type;
while ((current_type = _dbus_type_reader_get_current_type (reader)) != DBUS_TYPE_INVALID)
{
if (dbus_type_is_container (current_type))
{
DBusTypeReader subreader;
DBusTypeWriter subwriter;
const DBusString *sig_str;
int sig_start;
int sig_len;
dbus_bool_t enabled_at_recurse;
dbus_bool_t past_start_after;
int reader_array_len_pos;
int reader_array_start_pos;
dbus_bool_t this_is_start_after;
/* type_pos is checked since e.g. in a struct the struct
* and its first field have the same value_pos.
* type_str will differ in reader/start_after for variants
* where type_str is inside the value_str
*/
if (!inside_start_after && start_after &&
reader->value_pos == start_after->value_pos &&
reader->type_str == start_after->type_str &&
reader->type_pos == start_after->type_pos)
this_is_start_after = TRUE;
else
this_is_start_after = FALSE;
_dbus_type_reader_recurse (reader, &subreader);
if (current_type == DBUS_TYPE_ARRAY)
{
reader_array_len_pos = ARRAY_READER_LEN_POS (&subreader);
reader_array_start_pos = subreader.u.array.start_pos;
}
else
{
/* quiet gcc */
reader_array_len_pos = -1;
reader_array_start_pos = -1;
}
_dbus_type_reader_get_signature (&subreader, &sig_str,
&sig_start, &sig_len);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("about to recurse into %s reader at %d subreader at %d writer at %d start_after reader at %d write target len %d inside_start_after = %d this_is_start_after = %d\n",
_dbus_type_to_string (current_type),
reader->value_pos,
subreader.value_pos,
writer->value_pos,
start_after ? start_after->value_pos : -1,
_dbus_string_get_length (writer->value_str),
inside_start_after, this_is_start_after);
#endif
if (!inside_start_after && !this_is_start_after)
enable_if_after (writer, &subreader, start_after);
enabled_at_recurse = writer->enabled;
if (!_dbus_type_writer_recurse_contained_len (writer, current_type,
sig_str, sig_start, sig_len,
&subwriter, FALSE))
goto oom;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("recursed into subwriter at %d write target len %d\n",
subwriter.value_pos,
_dbus_string_get_length (subwriter.value_str));
#endif
if (!writer_write_reader_helper (&subwriter, &subreader, start_after,
start_after_new_pos, start_after_new_len,
fixups,
inside_start_after ||
this_is_start_after))
goto oom;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("about to unrecurse from %s subreader at %d writer at %d subwriter at %d write target len %d\n",
_dbus_type_to_string (current_type),
subreader.value_pos,
writer->value_pos,
subwriter.value_pos,
_dbus_string_get_length (writer->value_str));
#endif
if (!inside_start_after && !this_is_start_after)
enable_if_after (writer, &subreader, start_after);
past_start_after = writer->enabled;
if (!_dbus_type_writer_unrecurse (writer, &subwriter))
goto oom;
/* If we weren't enabled when we recursed, we didn't
* write an array len; if we passed start_after
* somewhere inside the array, then we need to generate
* a fixup.
*/
if (start_after != NULL &&
!enabled_at_recurse && past_start_after &&
current_type == DBUS_TYPE_ARRAY &&
fixups != NULL)
{
DBusArrayLenFixup fixup;
int bytes_written_after_start_after;
int bytes_before_start_after;
int old_len;
/* this subwriter access is moderately unkosher since we
* already unrecursed, but it works as long as unrecurse
* doesn't break us on purpose
*/
bytes_written_after_start_after = writer_get_array_len (&subwriter);
bytes_before_start_after =
start_after->value_pos - reader_array_start_pos;
fixup.len_pos_in_reader = reader_array_len_pos;
fixup.new_len =
bytes_before_start_after +
start_after_new_len +
bytes_written_after_start_after;
_dbus_assert (_DBUS_ALIGN_VALUE (fixup.len_pos_in_reader, 4) ==
(unsigned) fixup.len_pos_in_reader);
old_len = _dbus_unpack_uint32 (reader->byte_order,
_dbus_string_get_const_udata_len (reader->value_str,
fixup.len_pos_in_reader, 4));
if (old_len != fixup.new_len && !append_fixup (fixups, &fixup))
goto oom;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("Generated fixup len_pos_in_reader = %d new_len = %d reader_array_start_pos = %d start_after->value_pos = %d bytes_before_start_after = %d start_after_new_len = %d bytes_written_after_start_after = %d\n",
fixup.len_pos_in_reader,
fixup.new_len,
reader_array_start_pos,
start_after->value_pos,
bytes_before_start_after,
start_after_new_len,
bytes_written_after_start_after);
#endif
}
}
else
{
DBusBasicValue val;
_dbus_assert (dbus_type_is_basic (current_type));
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("Reading basic value %s at %d\n",
_dbus_type_to_string (current_type),
reader->value_pos);
#endif
_dbus_type_reader_read_basic (reader, &val);
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("Writing basic value %s at %d write target len %d inside_start_after = %d\n",
_dbus_type_to_string (current_type),
writer->value_pos,
_dbus_string_get_length (writer->value_str),
inside_start_after);
#endif
if (!inside_start_after)
enable_if_after (writer, reader, start_after);
if (!_dbus_type_writer_write_basic (writer, current_type, &val))
goto oom;
#if RECURSIVE_MARSHAL_WRITE_TRACE
_dbus_verbose ("Wrote basic value %s, new value_pos %d write target len %d\n",
_dbus_type_to_string (current_type),
writer->value_pos,
_dbus_string_get_length (writer->value_str));
#endif
}
_dbus_type_reader_next (reader);
}
return TRUE;
oom:
if (fixups)
apply_and_free_fixups (fixups, NULL); /* NULL for reader to apply to */
return FALSE;
}
/*
* Iterate through all values in the given reader, writing a copy of
* each value to the writer. The reader will be moved forward to its
* end position.
*
* If a reader start_after is provided, it should be a reader for the
* same data as the reader to be written. Only values occurring after
* the value pointed to by start_after will be written to the writer.
*
* If start_after is provided, then the copy of the reader will be
* partial. This means that array lengths will not have been copied.
* The assumption is that you wrote a new version of the value at
* start_after to the writer. You have to pass in the start position
* and length of the new value. (If you are deleting the value
* at start_after, pass in 0 for the length.)
*
* If the fixups parameter is non-#NULL, then any array length that
* was read but not written due to start_after will be provided
* as a #DBusArrayLenFixup. The fixup contains the position of the
* array length in the source data, and the correct array length
* assuming you combine the source data before start_after with
* the written data at start_after and beyond.
*
* @param writer the writer to copy to
* @param reader the reader to copy from
* @param start_after #NULL or a reader showing where to start
* @param start_after_new_pos the position of start_after equivalent in the target data
* @param start_after_new_len the length of start_after equivalent in the target data
* @param fixups list to append #DBusArrayLenFixup if the write was partial
* @returns #FALSE if no memory
*/
static dbus_bool_t
_dbus_type_writer_write_reader_partial (DBusTypeWriter *writer,
DBusTypeReader *reader,
const DBusTypeReader *start_after,
int start_after_new_pos,
int start_after_new_len,
DBusList **fixups)
{
DBusTypeWriter orig;
int orig_type_len;
int orig_value_len;
int new_bytes;
int orig_enabled;
orig = *writer;
orig_type_len = _dbus_string_get_length (writer->type_str);
orig_value_len = _dbus_string_get_length (writer->value_str);
orig_enabled = writer->enabled;
if (start_after)
_dbus_type_writer_set_enabled (writer, FALSE);
if (!writer_write_reader_helper (writer, reader, start_after,
start_after_new_pos,
start_after_new_len,
fixups, FALSE))
goto oom;
_dbus_type_writer_set_enabled (writer, orig_enabled);
return TRUE;
oom:
if (!writer->type_pos_is_expectation)
{
new_bytes = _dbus_string_get_length (writer->type_str) - orig_type_len;
_dbus_string_delete (writer->type_str, orig.type_pos, new_bytes);
}
new_bytes = _dbus_string_get_length (writer->value_str) - orig_value_len;
_dbus_string_delete (writer->value_str, orig.value_pos, new_bytes);
*writer = orig;
return FALSE;
}
/**
* Iterate through all values in the given reader, writing a copy of
* each value to the writer. The reader will be moved forward to its
* end position.
*
* @param writer the writer to copy to
* @param reader the reader to copy from
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_type_writer_write_reader (DBusTypeWriter *writer,
DBusTypeReader *reader)
{
return _dbus_type_writer_write_reader_partial (writer, reader, NULL, 0, 0, NULL);
}
/*
* If disabled, a writer can still be iterated forward and recursed/unrecursed
* but won't write any values. Types will still be written unless the
* writer is a "values only" writer, because the writer needs access to
* a valid signature to be able to iterate.
*
* @param writer the type writer
* @param enabled #TRUE if values should be written
*/
static void
_dbus_type_writer_set_enabled (DBusTypeWriter *writer,
dbus_bool_t enabled)
{
writer->enabled = enabled != FALSE;
}
/** @} */ /* end of DBusMarshal group */
/* tests in dbus-marshal-recursive-util.c */
Reference in a new issue View git blame Copy permalink