1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-marshal-recursive.c Marshalling routines for recursive types
3 *
4 * Copyright (C) 2004, 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-recursive.h"
26 #include "dbus-marshal-basic.h"
27 #include "dbus-signature.h"
28 #include "dbus-internals.h"
29
30 /**
31 * @addtogroup DBusMarshal
32 * @{
33 */
34
35 static dbus_bool_t _dbus_type_reader_greater_than (const DBusTypeReader *lhs,
36 const DBusTypeReader *rhs);
37
38 static void _dbus_type_writer_set_enabled (DBusTypeWriter *writer,
39 dbus_bool_t enabled);
40 static dbus_bool_t _dbus_type_writer_write_reader_partial (DBusTypeWriter *writer,
41 DBusTypeReader *reader,
42 const DBusTypeReader *start_after,
43 int start_after_new_pos,
44 int start_after_new_len,
45 DBusList **fixups);
46
47 /** turn this on to get deluged in TypeReader verbose spam */
48 #define RECURSIVE_MARSHAL_READ_TRACE 0
49
50 /** turn this on to get deluged in TypeWriter verbose spam */
51 #define RECURSIVE_MARSHAL_WRITE_TRACE 0
52
53 static void
free_fixups(DBusList ** fixups)54 free_fixups (DBusList **fixups)
55 {
56 DBusList *link;
57
58 link = _dbus_list_get_first_link (fixups);
59 while (link != NULL)
60 {
61 DBusList *next;
62
63 next = _dbus_list_get_next_link (fixups, link);
64
65 dbus_free (link->data);
66 _dbus_list_free_link (link);
67
68 link = next;
69 }
70
71 *fixups = NULL;
72 }
73
74 static void
apply_and_free_fixups(DBusList ** fixups,DBusTypeReader * reader)75 apply_and_free_fixups (DBusList **fixups,
76 DBusTypeReader *reader)
77 {
78 DBusList *link;
79
80 #if RECURSIVE_MARSHAL_WRITE_TRACE
81 if (*fixups)
82 _dbus_verbose (" %d FIXUPS to apply\n",
83 _dbus_list_get_length (fixups));
84 #endif
85
86 link = _dbus_list_get_first_link (fixups);
87 while (link != NULL)
88 {
89 DBusList *next;
90
91 next = _dbus_list_get_next_link (fixups, link);
92
93 if (reader)
94 {
95 DBusArrayLenFixup *f;
96
97 f = link->data;
98
99 #if RECURSIVE_MARSHAL_WRITE_TRACE
100 _dbus_verbose (" applying FIXUP to reader %p at pos %d new_len = %d old len %d\n",
101 reader, f->len_pos_in_reader, f->new_len,
102 _dbus_marshal_read_uint32 (reader->value_str,
103 f->len_pos_in_reader,
104 reader->byte_order, NULL));
105 #endif
106
107 _dbus_marshal_set_uint32 ((DBusString*) reader->value_str,
108 f->len_pos_in_reader,
109 f->new_len,
110 reader->byte_order);
111 }
112
113 dbus_free (link->data);
114 _dbus_list_free_link (link);
115
116 link = next;
117 }
118
119 *fixups = NULL;
120 }
121
122 /**
123 * Virtual table for a type reader.
124 */
125 struct DBusTypeReaderClass
126 {
127 const char *name; /**< name for debugging */
128 int id; /**< index in all_reader_classes */
129 dbus_bool_t types_only; /**< only iterates over types, not values */
130 void (* recurse) (DBusTypeReader *sub,
131 DBusTypeReader *parent); /**< recurse with this reader as sub */
132 dbus_bool_t (* check_finished) (const DBusTypeReader *reader); /**< check whether reader is at the end */
133 void (* next) (DBusTypeReader *reader,
134 int current_type); /**< go to the next value */
135 };
136
137 static int
element_type_get_alignment(const DBusString * str,int pos)138 element_type_get_alignment (const DBusString *str,
139 int pos)
140 {
141 return _dbus_type_get_alignment (_dbus_first_type_in_signature (str, pos));
142 }
143
144 static void
reader_init(DBusTypeReader * reader,int byte_order,const DBusString * type_str,int type_pos,const DBusString * value_str,int value_pos)145 reader_init (DBusTypeReader *reader,
146 int byte_order,
147 const DBusString *type_str,
148 int type_pos,
149 const DBusString *value_str,
150 int value_pos)
151 {
152 _DBUS_ZERO (*reader);
153 reader->byte_order = byte_order;
154 reader->finished = FALSE;
155 reader->type_str = type_str;
156 reader->type_pos = type_pos;
157 reader->value_str = value_str;
158 reader->value_pos = value_pos;
159 }
160
161 static void
base_reader_recurse(DBusTypeReader * sub,DBusTypeReader * parent)162 base_reader_recurse (DBusTypeReader *sub,
163 DBusTypeReader *parent)
164 {
165 /* point subreader at the same place as parent */
166 reader_init (sub,
167 parent->byte_order,
168 parent->type_str,
169 parent->type_pos,
170 parent->value_str,
171 parent->value_pos);
172 }
173
174 static void
struct_or_dict_entry_types_only_reader_recurse(DBusTypeReader * sub,DBusTypeReader * parent)175 struct_or_dict_entry_types_only_reader_recurse (DBusTypeReader *sub,
176 DBusTypeReader *parent)
177 {
178 base_reader_recurse (sub, parent);
179
180 _dbus_assert (_dbus_string_get_byte (sub->type_str,
181 sub->type_pos) == DBUS_STRUCT_BEGIN_CHAR ||
182 _dbus_string_get_byte (sub->type_str,
183 sub->type_pos) == DBUS_DICT_ENTRY_BEGIN_CHAR);
184
185 sub->type_pos += 1;
186 }
187
188 static void
struct_or_dict_entry_reader_recurse(DBusTypeReader * sub,DBusTypeReader * parent)189 struct_or_dict_entry_reader_recurse (DBusTypeReader *sub,
190 DBusTypeReader *parent)
191 {
192 struct_or_dict_entry_types_only_reader_recurse (sub, parent);
193
194 /* struct and dict entry have 8 byte alignment */
195 sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 8);
196 }
197
198 static void
array_types_only_reader_recurse(DBusTypeReader * sub,DBusTypeReader * parent)199 array_types_only_reader_recurse (DBusTypeReader *sub,
200 DBusTypeReader *parent)
201 {
202 base_reader_recurse (sub, parent);
203
204 /* point type_pos at the array element type */
205 sub->type_pos += 1;
206
207 /* Init with values likely to crash things if misused */
208 sub->u.array.start_pos = _DBUS_INT_MAX;
209 sub->array_len_offset = 7;
210 }
211
212 /** compute position of array length given array_len_offset, which is
213 the offset back from start_pos to end of the len */
214 #define ARRAY_READER_LEN_POS(reader) \
215 ((reader)->u.array.start_pos - ((int)(reader)->array_len_offset) - 4)
216
217 static int
array_reader_get_array_len(const DBusTypeReader * reader)218 array_reader_get_array_len (const DBusTypeReader *reader)
219 {
220 dbus_uint32_t array_len;
221 int len_pos;
222
223 len_pos = ARRAY_READER_LEN_POS (reader);
224
225 _dbus_assert (_DBUS_ALIGN_VALUE (len_pos, 4) == (unsigned) len_pos);
226 array_len = _dbus_unpack_uint32 (reader->byte_order,
227 _dbus_string_get_const_udata_len (reader->value_str, len_pos, 4));
228
229 #if RECURSIVE_MARSHAL_READ_TRACE
230 _dbus_verbose (" reader %p len_pos %d array len %u len_offset %d\n",
231 reader, len_pos, array_len, reader->array_len_offset);
232 #endif
233
234 _dbus_assert (reader->u.array.start_pos - len_pos - 4 < 8);
235
236 return array_len;
237 }
238
239 static void
array_reader_recurse(DBusTypeReader * sub,DBusTypeReader * parent)240 array_reader_recurse (DBusTypeReader *sub,
241 DBusTypeReader *parent)
242 {
243 int alignment;
244 int len_pos;
245
246 array_types_only_reader_recurse (sub, parent);
247
248 sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 4);
249
250 len_pos = sub->value_pos;
251
252 sub->value_pos += 4; /* for the length */
253
254 alignment = element_type_get_alignment (sub->type_str,
255 sub->type_pos);
256
257 sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, alignment);
258
259 sub->u.array.start_pos = sub->value_pos;
260 _dbus_assert ((sub->u.array.start_pos - (len_pos + 4)) < 8); /* only 3 bits in array_len_offset */
261 sub->array_len_offset = sub->u.array.start_pos - (len_pos + 4);
262
263 #if RECURSIVE_MARSHAL_READ_TRACE
264 _dbus_verbose (" type reader %p array start = %d len_offset = %d array len = %d array element type = %s\n",
265 sub,
266 sub->u.array.start_pos,
267 sub->array_len_offset,
268 array_reader_get_array_len (sub),
269 _dbus_type_to_string (_dbus_first_type_in_signature (sub->type_str,
270 sub->type_pos)));
271 #endif
272 }
273
274 static void
variant_reader_recurse(DBusTypeReader * sub,DBusTypeReader * parent)275 variant_reader_recurse (DBusTypeReader *sub,
276 DBusTypeReader *parent)
277 {
278 int sig_len;
279 int contained_alignment;
280
281 base_reader_recurse (sub, parent);
282
283 /* Variant is 1 byte sig length (without nul), signature with nul,
284 * padding to 8-boundary, then values
285 */
286
287 sig_len = _dbus_string_get_byte (sub->value_str, sub->value_pos);
288
289 sub->type_str = sub->value_str;
290 sub->type_pos = sub->value_pos + 1;
291
292 sub->value_pos = sub->type_pos + sig_len + 1;
293
294 contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (sub->type_str,
295 sub->type_pos));
296
297 sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, contained_alignment);
298
299 #if RECURSIVE_MARSHAL_READ_TRACE
300 _dbus_verbose (" type reader %p variant containing '%s'\n",
301 sub,
302 _dbus_string_get_const_data_len (sub->type_str,
303 sub->type_pos, 0));
304 #endif
305 }
306
307 static dbus_bool_t
array_reader_check_finished(const DBusTypeReader * reader)308 array_reader_check_finished (const DBusTypeReader *reader)
309 {
310 int end_pos;
311
312 /* return the array element type if elements remain, and
313 * TYPE_INVALID otherwise
314 */
315
316 end_pos = reader->u.array.start_pos + array_reader_get_array_len (reader);
317
318 _dbus_assert (reader->value_pos <= end_pos);
319 _dbus_assert (reader->value_pos >= reader->u.array.start_pos);
320
321 return reader->value_pos == end_pos;
322 }
323
324 static void
skip_one_complete_type(const DBusString * type_str,int * type_pos)325 skip_one_complete_type (const DBusString *type_str,
326 int *type_pos)
327 {
328 _dbus_type_signature_next (_dbus_string_get_const_data (type_str),
329 type_pos);
330 }
331
332 /**
333 * Skips to the next "complete" type inside a type signature.
334 * The signature is read starting at type_pos, and the next
335 * type position is stored in the same variable.
336 *
337 * @param type_str a type signature (must be valid)
338 * @param type_pos an integer position in the type signature (in and out)
339 */
340 void
_dbus_type_signature_next(const char * type_str,int * type_pos)341 _dbus_type_signature_next (const char *type_str,
342 int *type_pos)
343 {
344 const unsigned char *p;
345 const unsigned char *start;
346
347 _dbus_assert (type_str != NULL);
348 _dbus_assert (type_pos != NULL);
349
350 start = (const unsigned char *)type_str;
351 p = start + *type_pos;
352
353 _dbus_assert (*p != DBUS_STRUCT_END_CHAR);
354 _dbus_assert (*p != DBUS_DICT_ENTRY_END_CHAR);
355
356 while (*p == DBUS_TYPE_ARRAY)
357 ++p;
358
359 _dbus_assert (*p != DBUS_STRUCT_END_CHAR);
360 _dbus_assert (*p != DBUS_DICT_ENTRY_END_CHAR);
361
362 if (*p == DBUS_STRUCT_BEGIN_CHAR)
363 {
364 int depth;
365
366 depth = 1;
367
368 while (TRUE)
369 {
370 _dbus_assert (*p != DBUS_TYPE_INVALID);
371
372 ++p;
373
374 _dbus_assert (*p != DBUS_TYPE_INVALID);
375
376 if (*p == DBUS_STRUCT_BEGIN_CHAR)
377 depth += 1;
378 else if (*p == DBUS_STRUCT_END_CHAR)
379 {
380 depth -= 1;
381 if (depth == 0)
382 {
383 ++p;
384 break;
385 }
386 }
387 }
388 }
389 else if (*p == DBUS_DICT_ENTRY_BEGIN_CHAR)
390 {
391 int depth;
392
393 depth = 1;
394
395 while (TRUE)
396 {
397 _dbus_assert (*p != DBUS_TYPE_INVALID);
398
399 ++p;
400
401 _dbus_assert (*p != DBUS_TYPE_INVALID);
402
403 if (*p == DBUS_DICT_ENTRY_BEGIN_CHAR)
404 depth += 1;
405 else if (*p == DBUS_DICT_ENTRY_END_CHAR)
406 {
407 depth -= 1;
408 if (depth == 0)
409 {
410 ++p;
411 break;
412 }
413 }
414 }
415 }
416 else
417 {
418 ++p;
419 }
420
421 *type_pos = (int) (p - start);
422 }
423
424 static int
find_len_of_complete_type(const DBusString * type_str,int type_pos)425 find_len_of_complete_type (const DBusString *type_str,
426 int type_pos)
427 {
428 int end;
429
430 end = type_pos;
431
432 skip_one_complete_type (type_str, &end);
433
434 return end - type_pos;
435 }
436
437 static void
base_reader_next(DBusTypeReader * reader,int current_type)438 base_reader_next (DBusTypeReader *reader,
439 int current_type)
440 {
441 switch (current_type)
442 {
443 case DBUS_TYPE_DICT_ENTRY:
444 case DBUS_TYPE_STRUCT:
445 case DBUS_TYPE_VARIANT:
446 /* Scan forward over the entire container contents */
447 {
448 DBusTypeReader sub;
449
450 if (reader->klass->types_only && current_type == DBUS_TYPE_VARIANT)
451 ;
452 else
453 {
454 /* Recurse into the struct or variant */
455 _dbus_type_reader_recurse (reader, &sub);
456
457 /* Skip everything in this subreader */
458 while (_dbus_type_reader_next (&sub))
459 {
460 /* nothing */;
461 }
462 }
463 if (!reader->klass->types_only)
464 reader->value_pos = sub.value_pos;
465
466 /* Now we are at the end of this container; for variants, the
467 * subreader's type_pos is totally inapplicable (it's in the
468 * value string) but we know that we increment by one past the
469 * DBUS_TYPE_VARIANT
470 */
471 if (current_type == DBUS_TYPE_VARIANT)
472 reader->type_pos += 1;
473 else
474 reader->type_pos = sub.type_pos;
475 }
476 break;
477
478 case DBUS_TYPE_ARRAY:
479 {
480 if (!reader->klass->types_only)
481 _dbus_marshal_skip_array (reader->value_str,
482 _dbus_first_type_in_signature (reader->type_str,
483 reader->type_pos + 1),
484 reader->byte_order,
485 &reader->value_pos);
486
487 skip_one_complete_type (reader->type_str, &reader->type_pos);
488 }
489 break;
490
491 default:
492 if (!reader->klass->types_only)
493 _dbus_marshal_skip_basic (reader->value_str,
494 current_type, reader->byte_order,
495 &reader->value_pos);
496
497 reader->type_pos += 1;
498 break;
499 }
500 }
501
502 static void
struct_reader_next(DBusTypeReader * reader,int current_type)503 struct_reader_next (DBusTypeReader *reader,
504 int current_type)
505 {
506 int t;
507
508 base_reader_next (reader, current_type);
509
510 /* for STRUCT containers we return FALSE at the end of the struct,
511 * for INVALID we return FALSE at the end of the signature.
512 * In both cases we arrange for get_current_type() to return INVALID
513 * which is defined to happen iff we're at the end (no more next())
514 */
515 t = _dbus_string_get_byte (reader->type_str, reader->type_pos);
516 if (t == DBUS_STRUCT_END_CHAR)
517 {
518 reader->type_pos += 1;
519 reader->finished = TRUE;
520 }
521 }
522
523 static void
dict_entry_reader_next(DBusTypeReader * reader,int current_type)524 dict_entry_reader_next (DBusTypeReader *reader,
525 int current_type)
526 {
527 int t;
528
529 base_reader_next (reader, current_type);
530
531 /* for STRUCT containers we return FALSE at the end of the struct,
532 * for INVALID we return FALSE at the end of the signature.
533 * In both cases we arrange for get_current_type() to return INVALID
534 * which is defined to happen iff we're at the end (no more next())
535 */
536 t = _dbus_string_get_byte (reader->type_str, reader->type_pos);
537 if (t == DBUS_DICT_ENTRY_END_CHAR)
538 {
539 reader->type_pos += 1;
540 reader->finished = TRUE;
541 }
542 }
543
544 static void
array_types_only_reader_next(DBusTypeReader * reader,int current_type)545 array_types_only_reader_next (DBusTypeReader *reader,
546 int current_type)
547 {
548 /* We have one "element" to be iterated over
549 * in each array, which is its element type.
550 * So the finished flag indicates whether we've
551 * iterated over it yet or not.
552 */
553 reader->finished = TRUE;
554 }
555
556 static void
array_reader_next(DBusTypeReader * reader,int current_type)557 array_reader_next (DBusTypeReader *reader,
558 int current_type)
559 {
560 /* Skip one array element */
561 int end_pos;
562
563 end_pos = reader->u.array.start_pos + array_reader_get_array_len (reader);
564
565 #if RECURSIVE_MARSHAL_READ_TRACE
566 _dbus_verbose (" reader %p array next START start_pos = %d end_pos = %d value_pos = %d current_type = %s\n",
567 reader,
568 reader->u.array.start_pos,
569 end_pos, reader->value_pos,
570 _dbus_type_to_string (current_type));
571 #endif
572
573 _dbus_assert (reader->value_pos < end_pos);
574 _dbus_assert (reader->value_pos >= reader->u.array.start_pos);
575
576 switch (_dbus_first_type_in_signature (reader->type_str,
577 reader->type_pos))
578 {
579 case DBUS_TYPE_DICT_ENTRY:
580 case DBUS_TYPE_STRUCT:
581 case DBUS_TYPE_VARIANT:
582 {
583 DBusTypeReader sub;
584
585 /* Recurse into the struct or variant */
586 _dbus_type_reader_recurse (reader, &sub);
587
588 /* Skip everything in this element */
589 while (_dbus_type_reader_next (&sub))
590 {
591 /* nothing */;
592 }
593
594 /* Now we are at the end of this element */
595 reader->value_pos = sub.value_pos;
596 }
597 break;
598
599 case DBUS_TYPE_ARRAY:
600 {
601 _dbus_marshal_skip_array (reader->value_str,
602 _dbus_first_type_in_signature (reader->type_str,
603 reader->type_pos + 1),
604 reader->byte_order,
605 &reader->value_pos);
606 }
607 break;
608
609 default:
610 {
611 _dbus_marshal_skip_basic (reader->value_str,
612 current_type, reader->byte_order,
613 &reader->value_pos);
614 }
615 break;
616 }
617
618 #if RECURSIVE_MARSHAL_READ_TRACE
619 _dbus_verbose (" reader %p array next END start_pos = %d end_pos = %d value_pos = %d current_type = %s\n",
620 reader,
621 reader->u.array.start_pos,
622 end_pos, reader->value_pos,
623 _dbus_type_to_string (current_type));
624 #endif
625
626 _dbus_assert (reader->value_pos <= end_pos);
627
628 if (reader->value_pos == end_pos)
629 {
630 skip_one_complete_type (reader->type_str,
631 &reader->type_pos);
632 }
633 }
634
635 static const DBusTypeReaderClass body_reader_class = {
636 "body", 0,
637 FALSE,
638 NULL, /* body is always toplevel, so doesn't get recursed into */
639 NULL,
640 base_reader_next
641 };
642
643 static const DBusTypeReaderClass body_types_only_reader_class = {
644 "body types", 1,
645 TRUE,
646 NULL, /* body is always toplevel, so doesn't get recursed into */
647 NULL,
648 base_reader_next
649 };
650
651 static const DBusTypeReaderClass struct_reader_class = {
652 "struct", 2,
653 FALSE,
654 struct_or_dict_entry_reader_recurse,
655 NULL,
656 struct_reader_next
657 };
658
659 static const DBusTypeReaderClass struct_types_only_reader_class = {
660 "struct types", 3,
661 TRUE,
662 struct_or_dict_entry_types_only_reader_recurse,
663 NULL,
664 struct_reader_next
665 };
666
667 static const DBusTypeReaderClass dict_entry_reader_class = {
668 "dict_entry", 4,
669 FALSE,
670 struct_or_dict_entry_reader_recurse,
671 NULL,
672 dict_entry_reader_next
673 };
674
675 static const DBusTypeReaderClass dict_entry_types_only_reader_class = {
676 "dict_entry types", 5,
677 TRUE,
678 struct_or_dict_entry_types_only_reader_recurse,
679 NULL,
680 dict_entry_reader_next
681 };
682
683 static const DBusTypeReaderClass array_reader_class = {
684 "array", 6,
685 FALSE,
686 array_reader_recurse,
687 array_reader_check_finished,
688 array_reader_next
689 };
690
691 static const DBusTypeReaderClass array_types_only_reader_class = {
692 "array types", 7,
693 TRUE,
694 array_types_only_reader_recurse,
695 NULL,
696 array_types_only_reader_next
697 };
698
699 static const DBusTypeReaderClass variant_reader_class = {
700 "variant", 8,
701 FALSE,
702 variant_reader_recurse,
703 NULL,
704 base_reader_next
705 };
706
707 #ifndef DBUS_DISABLE_ASSERT
708 static const DBusTypeReaderClass * const
709 all_reader_classes[] = {
710 &body_reader_class,
711 &body_types_only_reader_class,
712 &struct_reader_class,
713 &struct_types_only_reader_class,
714 &dict_entry_reader_class,
715 &dict_entry_types_only_reader_class,
716 &array_reader_class,
717 &array_types_only_reader_class,
718 &variant_reader_class
719 };
720 #endif
721
722 /**
723 * Initializes a type reader.
724 *
725 * @param reader the reader
726 * @param byte_order the byte order of the block to read
727 * @param type_str the signature of the block to read
728 * @param type_pos location of signature
729 * @param value_str the string containing values block
730 * @param value_pos start of values block
731 */
732 void
_dbus_type_reader_init(DBusTypeReader * reader,int byte_order,const DBusString * type_str,int type_pos,const DBusString * value_str,int value_pos)733 _dbus_type_reader_init (DBusTypeReader *reader,
734 int byte_order,
735 const DBusString *type_str,
736 int type_pos,
737 const DBusString *value_str,
738 int value_pos)
739 {
740 reader_init (reader, byte_order, type_str, type_pos,
741 value_str, value_pos);
742
743 reader->klass = &body_reader_class;
744
745 #if RECURSIVE_MARSHAL_READ_TRACE
746 _dbus_verbose (" type reader %p init type_pos = %d value_pos = %d remaining sig '%s'\n",
747 reader, reader->type_pos, reader->value_pos,
748 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
749 #endif
750 }
751
752 /**
753 * Like _dbus_type_reader_init() but the iteration is over the
754 * signature, not over values.
755 *
756 * @param reader the reader
757 * @param type_str the signature string
758 * @param type_pos location in the signature string
759 */
760 void
_dbus_type_reader_init_types_only(DBusTypeReader * reader,const DBusString * type_str,int type_pos)761 _dbus_type_reader_init_types_only (DBusTypeReader *reader,
762 const DBusString *type_str,
763 int type_pos)
764 {
765 reader_init (reader, DBUS_COMPILER_BYTE_ORDER /* irrelevant */,
766 type_str, type_pos, NULL, _DBUS_INT_MAX /* crashes if we screw up */);
767
768 reader->klass = &body_types_only_reader_class;
769
770 #if RECURSIVE_MARSHAL_READ_TRACE
771 _dbus_verbose (" type reader %p init types only type_pos = %d remaining sig '%s'\n",
772 reader, reader->type_pos,
773 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
774 #endif
775 }
776
777 /**
778 * Gets the type of the value the reader is currently pointing to;
779 * or for a types-only reader gets the type it's currently pointing to.
780 * If the reader is at the end of a block or end of a container such
781 * as an array, returns #DBUS_TYPE_INVALID.
782 *
783 * @param reader the reader
784 */
785 int
_dbus_type_reader_get_current_type(const DBusTypeReader * reader)786 _dbus_type_reader_get_current_type (const DBusTypeReader *reader)
787 {
788 int t;
789
790 if (reader->finished ||
791 (reader->klass->check_finished &&
792 (* reader->klass->check_finished) (reader)))
793 t = DBUS_TYPE_INVALID;
794 else
795 t = _dbus_first_type_in_signature (reader->type_str,
796 reader->type_pos);
797
798 _dbus_assert (t != DBUS_STRUCT_END_CHAR);
799 _dbus_assert (t != DBUS_STRUCT_BEGIN_CHAR);
800 _dbus_assert (t != DBUS_DICT_ENTRY_END_CHAR);
801 _dbus_assert (t != DBUS_DICT_ENTRY_BEGIN_CHAR);
802
803 #if 0
804 _dbus_verbose (" type reader %p current type_pos = %d type = %s\n",
805 reader, reader->type_pos,
806 _dbus_type_to_string (t));
807 #endif
808
809 return t;
810 }
811
812 /**
813 * Gets the type of an element of the array the reader is currently
814 * pointing to. It's an error to call this if
815 * _dbus_type_reader_get_current_type() doesn't return #DBUS_TYPE_ARRAY
816 * for this reader.
817 *
818 * @param reader the reader
819 */
820 int
_dbus_type_reader_get_element_type(const DBusTypeReader * reader)821 _dbus_type_reader_get_element_type (const DBusTypeReader *reader)
822 {
823 int element_type;
824
825 _dbus_assert (_dbus_type_reader_get_current_type (reader) == DBUS_TYPE_ARRAY);
826
827 element_type = _dbus_first_type_in_signature (reader->type_str,
828 reader->type_pos + 1);
829
830 return element_type;
831 }
832
833 /**
834 * Gets the current position in the value block
835 * @param reader the reader
836 */
837 int
_dbus_type_reader_get_value_pos(const DBusTypeReader * reader)838 _dbus_type_reader_get_value_pos (const DBusTypeReader *reader)
839 {
840 return reader->value_pos;
841 }
842
843 /**
844 * Get the address of the marshaled value in the data being read. The
845 * address may not be aligned; you have to align it to the type of the
846 * value you want to read. Most of the demarshal routines do this for
847 * you.
848 *
849 * @param reader the reader
850 * @param value_location the address of the marshaled value
851 */
852 void
_dbus_type_reader_read_raw(const DBusTypeReader * reader,const unsigned char ** value_location)853 _dbus_type_reader_read_raw (const DBusTypeReader *reader,
854 const unsigned char **value_location)
855 {
856 _dbus_assert (!reader->klass->types_only);
857
858 *value_location = _dbus_string_get_const_udata_len (reader->value_str,
859 reader->value_pos,
860 0);
861 }
862
863 /**
864 * Reads a basic-typed value, as with _dbus_marshal_read_basic().
865 *
866 * @param reader the reader
867 * @param value the address of the value
868 */
869 void
_dbus_type_reader_read_basic(const DBusTypeReader * reader,void * value)870 _dbus_type_reader_read_basic (const DBusTypeReader *reader,
871 void *value)
872 {
873 int t;
874
875 _dbus_assert (!reader->klass->types_only);
876
877 t = _dbus_type_reader_get_current_type (reader);
878
879 _dbus_marshal_read_basic (reader->value_str,
880 reader->value_pos,
881 t, value,
882 reader->byte_order,
883 NULL);
884
885
886 #if RECURSIVE_MARSHAL_READ_TRACE
887 _dbus_verbose (" type reader %p read basic type_pos = %d value_pos = %d remaining sig '%s'\n",
888 reader, reader->type_pos, reader->value_pos,
889 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
890 #endif
891 }
892
893 /**
894 * Returns the number of bytes in the array.
895 *
896 * @param reader the reader to read from
897 * @returns the number of bytes in the array
898 */
899 int
_dbus_type_reader_get_array_length(const DBusTypeReader * reader)900 _dbus_type_reader_get_array_length (const DBusTypeReader *reader)
901 {
902 _dbus_assert (!reader->klass->types_only);
903 _dbus_assert (reader->klass == &array_reader_class);
904
905 return array_reader_get_array_len (reader);
906 }
907
908 /**
909 * Reads a block of fixed-length basic values, from the current point
910 * in an array to the end of the array. Does not work for arrays of
911 * string or container types.
912 *
913 * This function returns the array in-place; it does not make a copy,
914 * and it does not swap the bytes.
915 *
916 * If you ask for #DBUS_TYPE_DOUBLE you will get a "const double*" back
917 * and the "value" argument should be a "const double**" and so on.
918 *
919 * @param reader the reader to read from
920 * @param value place to return the array values
921 * @param n_elements place to return number of array elements
922 */
923 void
_dbus_type_reader_read_fixed_multi(const DBusTypeReader * reader,void * value,int * n_elements)924 _dbus_type_reader_read_fixed_multi (const DBusTypeReader *reader,
925 void *value,
926 int *n_elements)
927 {
928 int element_type;
929 int end_pos;
930 int remaining_len;
931 int alignment;
932 int total_len;
933
934 _dbus_assert (!reader->klass->types_only);
935 _dbus_assert (reader->klass == &array_reader_class);
936
937 element_type = _dbus_first_type_in_signature (reader->type_str,
938 reader->type_pos);
939
940 _dbus_assert (element_type != DBUS_TYPE_INVALID); /* why we don't use get_current_type() */
941 _dbus_assert (dbus_type_is_fixed (element_type));
942
943 alignment = _dbus_type_get_alignment (element_type);
944
945 _dbus_assert (reader->value_pos >= reader->u.array.start_pos);
946
947 total_len = array_reader_get_array_len (reader);
948 end_pos = reader->u.array.start_pos + total_len;
949 remaining_len = end_pos - reader->value_pos;
950
951 #if RECURSIVE_MARSHAL_READ_TRACE
952 _dbus_verbose ("end_pos %d total_len %d remaining_len %d value_pos %d\n",
953 end_pos, total_len, remaining_len, reader->value_pos);
954 #endif
955
956 _dbus_assert (remaining_len <= total_len);
957
958 if (remaining_len == 0)
959 *(const DBusBasicValue**) value = NULL;
960 else
961 *(const DBusBasicValue**) value =
962 (void*) _dbus_string_get_const_data_len (reader->value_str,
963 reader->value_pos,
964 remaining_len);
965
966 *n_elements = remaining_len / alignment;
967 _dbus_assert ((remaining_len % alignment) == 0);
968
969 #if RECURSIVE_MARSHAL_READ_TRACE
970 _dbus_verbose (" type reader %p read fixed array type_pos = %d value_pos = %d remaining sig '%s'\n",
971 reader, reader->type_pos, reader->value_pos,
972 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0));
973 #endif
974 }
975
976 /**
977 * Initialize a new reader pointing to the first type and
978 * corresponding value that's a child of the current container. It's
979 * an error to call this if the current type is a non-container.
980 *
981 * Note that DBusTypeReader traverses values, not types. So if you
982 * have an empty array of array of int, you can't recurse into it. You
983 * can only recurse into each element.
984 *
985 * @param reader the reader
986 * @param sub a reader to init pointing to the first child
987 */
988 void
_dbus_type_reader_recurse(DBusTypeReader * reader,DBusTypeReader * sub)989 _dbus_type_reader_recurse (DBusTypeReader *reader,
990 DBusTypeReader *sub)
991 {
992 int t;
993 const DBusTypeReaderClass *klass = NULL;
994
995 t = _dbus_first_type_in_signature (reader->type_str, reader->type_pos);
996
997 switch (t)
998 {
999 case DBUS_TYPE_STRUCT:
1000 if (reader->klass->types_only)
1001 klass = &struct_types_only_reader_class;
1002 else
1003 klass = &struct_reader_class;
1004 break;
1005 case DBUS_TYPE_DICT_ENTRY:
1006 if (reader->klass->types_only)
1007 klass = &dict_entry_types_only_reader_class;
1008 else
1009 klass = &dict_entry_reader_class;
1010 break;
1011 case DBUS_TYPE_ARRAY:
1012 if (reader->klass->types_only)
1013 klass = &array_types_only_reader_class;
1014 else
1015 klass = &array_reader_class;
1016 break;
1017 case DBUS_TYPE_VARIANT:
1018 if (reader->klass->types_only)
1019 _dbus_assert_not_reached ("can't recurse into variant typecode");
1020 else
1021 klass = &variant_reader_class;
1022 break;
1023 default:
1024 _dbus_verbose ("recursing into type %s\n", _dbus_type_to_string (t));
1025 #ifndef DBUS_DISABLE_CHECKS
1026 if (t == DBUS_TYPE_INVALID)
1027 _dbus_warn_check_failed ("You can't recurse into an empty array or off the end of a message body");
1028 #endif /* DBUS_DISABLE_CHECKS */
1029
1030 _dbus_assert_not_reached ("don't yet handle recursing into this type");
1031 }
1032
1033 _dbus_assert (klass != NULL);
1034 _dbus_assert (klass == all_reader_classes[klass->id]);
1035
1036 (* klass->recurse) (sub, reader);
1037 sub->klass = klass;
1038
1039 #if RECURSIVE_MARSHAL_READ_TRACE
1040 _dbus_verbose (" type reader %p RECURSED type_pos = %d value_pos = %d remaining sig '%s'\n",
1041 sub, sub->type_pos, sub->value_pos,
1042 _dbus_string_get_const_data_len (sub->type_str, sub->type_pos, 0));
1043 #endif
1044 }
1045
1046 /**
1047 * Skip to the next value on this "level". e.g. the next field in a
1048 * struct, the next value in an array. Returns FALSE at the end of the
1049 * current container.
1050 *
1051 * @param reader the reader
1052 * @returns FALSE if nothing more to read at or below this level
1053 */
1054 dbus_bool_t
_dbus_type_reader_next(DBusTypeReader * reader)1055 _dbus_type_reader_next (DBusTypeReader *reader)
1056 {
1057 int t;
1058
1059 t = _dbus_type_reader_get_current_type (reader);
1060
1061 #if RECURSIVE_MARSHAL_READ_TRACE
1062 _dbus_verbose (" type reader %p START next() { type_pos = %d value_pos = %d remaining sig '%s' current_type = %s\n",
1063 reader, reader->type_pos, reader->value_pos,
1064 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0),
1065 _dbus_type_to_string (t));
1066 #endif
1067
1068 if (t == DBUS_TYPE_INVALID)
1069 return FALSE;
1070
1071 (* reader->klass->next) (reader, t);
1072
1073 #if RECURSIVE_MARSHAL_READ_TRACE
1074 _dbus_verbose (" type reader %p END next() type_pos = %d value_pos = %d remaining sig '%s' current_type = %s\n",
1075 reader, reader->type_pos, reader->value_pos,
1076 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0),
1077 _dbus_type_to_string (_dbus_type_reader_get_current_type (reader)));
1078 #endif
1079
1080 return _dbus_type_reader_get_current_type (reader) != DBUS_TYPE_INVALID;
1081 }
1082
1083 /**
1084 * Check whether there's another value on this "level". e.g. the next
1085 * field in a struct, the next value in an array. Returns FALSE at the
1086 * end of the current container.
1087 *
1088 * You probably don't want to use this; it makes for an awkward for/while
1089 * loop. A nicer one is "while ((current_type = get_current_type()) != INVALID)"
1090 *
1091 * @param reader the reader
1092 * @returns FALSE if nothing more to read at or below this level
1093 */
1094 dbus_bool_t
_dbus_type_reader_has_next(const DBusTypeReader * reader)1095 _dbus_type_reader_has_next (const DBusTypeReader *reader)
1096 {
1097 /* Not efficient but works for now. */
1098 DBusTypeReader copy;
1099
1100 copy = *reader;
1101 return _dbus_type_reader_next (©);
1102 }
1103
1104 /**
1105 * Gets the string and range of said string containing the signature
1106 * of the current value. Essentially a more complete version of
1107 * _dbus_type_reader_get_current_type() (returns the full type
1108 * rather than only the outside of the onion).
1109 *
1110 * Note though that the first byte in a struct signature is
1111 * #DBUS_STRUCT_BEGIN_CHAR while the current type will be
1112 * #DBUS_TYPE_STRUCT so it isn't true that the first byte of the
1113 * signature is always the same as the current type. Another
1114 * difference is that this function will still return a signature when
1115 * inside an empty array; say you recurse into empty array of int32,
1116 * the signature is "i" but the current type will always be
1117 * #DBUS_TYPE_INVALID since there are no elements to be currently
1118 * pointing to.
1119 *
1120 * @param reader the reader
1121 * @param str_p place to return the string with the type in it
1122 * @param start_p place to return start of the type
1123 * @param len_p place to return the length of the type
1124 */
1125 void
_dbus_type_reader_get_signature(const DBusTypeReader * reader,const DBusString ** str_p,int * start_p,int * len_p)1126 _dbus_type_reader_get_signature (const DBusTypeReader *reader,
1127 const DBusString **str_p,
1128 int *start_p,
1129 int *len_p)
1130 {
1131 *str_p = reader->type_str;
1132 *start_p = reader->type_pos;
1133 *len_p = find_len_of_complete_type (reader->type_str, reader->type_pos);
1134 }
1135
1136 typedef struct
1137 {
1138 DBusString replacement; /**< Marshaled value including alignment padding */
1139 int padding; /**< How much of the replacement block is padding */
1140 } ReplacementBlock;
1141
1142 static dbus_bool_t
replacement_block_init(ReplacementBlock * block,DBusTypeReader * reader)1143 replacement_block_init (ReplacementBlock *block,
1144 DBusTypeReader *reader)
1145 {
1146 if (!_dbus_string_init (&block->replacement))
1147 return FALSE;
1148
1149 /* % 8 is the padding to have the same align properties in
1150 * our replacement string as we do at the position being replaced
1151 */
1152 block->padding = reader->value_pos % 8;
1153
1154 if (!_dbus_string_lengthen (&block->replacement, block->padding))
1155 goto oom;
1156
1157 return TRUE;
1158
1159 oom:
1160 _dbus_string_free (&block->replacement);
1161 return FALSE;
1162 }
1163
1164 static dbus_bool_t
replacement_block_replace(ReplacementBlock * block,DBusTypeReader * reader,const DBusTypeReader * realign_root)1165 replacement_block_replace (ReplacementBlock *block,
1166 DBusTypeReader *reader,
1167 const DBusTypeReader *realign_root)
1168 {
1169 DBusTypeWriter writer;
1170 DBusTypeReader realign_reader;
1171 DBusList *fixups;
1172 int orig_len;
1173
1174 _dbus_assert (realign_root != NULL);
1175
1176 orig_len = _dbus_string_get_length (&block->replacement);
1177
1178 realign_reader = *realign_root;
1179
1180 #if RECURSIVE_MARSHAL_WRITE_TRACE
1181 _dbus_verbose ("INITIALIZING replacement block writer %p at value_pos %d\n",
1182 &writer, _dbus_string_get_length (&block->replacement));
1183 #endif
1184 _dbus_type_writer_init_values_only (&writer,
1185 realign_reader.byte_order,
1186 realign_reader.type_str,
1187 realign_reader.type_pos,
1188 &block->replacement,
1189 _dbus_string_get_length (&block->replacement));
1190
1191 _dbus_assert (realign_reader.value_pos <= reader->value_pos);
1192
1193 #if RECURSIVE_MARSHAL_WRITE_TRACE
1194 _dbus_verbose ("COPYING from reader at value_pos %d to writer %p starting after value_pos %d\n",
1195 realign_reader.value_pos, &writer, reader->value_pos);
1196 #endif
1197 fixups = NULL;
1198 if (!_dbus_type_writer_write_reader_partial (&writer,
1199 &realign_reader,
1200 reader,
1201 block->padding,
1202 _dbus_string_get_length (&block->replacement) - block->padding,
1203 &fixups))
1204 goto oom;
1205
1206 #if RECURSIVE_MARSHAL_WRITE_TRACE
1207 _dbus_verbose ("REPLACEMENT at padding %d len %d\n", block->padding,
1208 _dbus_string_get_length (&block->replacement) - block->padding);
1209 _dbus_verbose_bytes_of_string (&block->replacement, block->padding,
1210 _dbus_string_get_length (&block->replacement) - block->padding);
1211 _dbus_verbose ("TO BE REPLACED at value_pos = %d (align pad %d) len %d realign_reader.value_pos %d\n",
1212 reader->value_pos, reader->value_pos % 8,
1213 realign_reader.value_pos - reader->value_pos,
1214 realign_reader.value_pos);
1215 _dbus_verbose_bytes_of_string (reader->value_str,
1216 reader->value_pos,
1217 realign_reader.value_pos - reader->value_pos);
1218 #endif
1219
1220 /* Move the replacement into position
1221 * (realign_reader should now be at the end of the block to be replaced)
1222 */
1223 if (!_dbus_string_replace_len (&block->replacement, block->padding,
1224 _dbus_string_get_length (&block->replacement) - block->padding,
1225 (DBusString*) reader->value_str,
1226 reader->value_pos,
1227 realign_reader.value_pos - reader->value_pos))
1228 goto oom;
1229
1230 /* Process our fixups now that we can't have an OOM error */
1231 apply_and_free_fixups (&fixups, reader);
1232
1233 return TRUE;
1234
1235 oom:
1236 _dbus_string_set_length (&block->replacement, orig_len);
1237 free_fixups (&fixups);
1238 return FALSE;
1239 }
1240
1241 static void
replacement_block_free(ReplacementBlock * block)1242 replacement_block_free (ReplacementBlock *block)
1243 {
1244 _dbus_string_free (&block->replacement);
1245 }
1246
1247 /* In the variable-length case, we have to fix alignment after we insert.
1248 * The strategy is as follows:
1249 *
1250 * - pad a new string to have the same alignment as the
1251 * start of the current basic value
1252 * - write the new basic value
1253 * - copy from the original reader to the new string,
1254 * which will fix the alignment of types following
1255 * the new value
1256 * - this copy has to start at realign_root,
1257 * but not really write anything until it
1258 * passes the value being set
1259 * - as an optimization, we can stop copying
1260 * when the source and dest values are both
1261 * on an 8-boundary, since we know all following
1262 * padding and alignment will be identical
1263 * - copy the new string back to the original
1264 * string, replacing the relevant part of the
1265 * original string
1266 * - now any arrays in the original string that
1267 * contained the replaced string may have the
1268 * wrong length; so we have to fix that
1269 */
1270 static dbus_bool_t
reader_set_basic_variable_length(DBusTypeReader * reader,int current_type,const void * value,const DBusTypeReader * realign_root)1271 reader_set_basic_variable_length (DBusTypeReader *reader,
1272 int current_type,
1273 const void *value,
1274 const DBusTypeReader *realign_root)
1275 {
1276 dbus_bool_t retval;
1277 ReplacementBlock block;
1278 DBusTypeWriter writer;
1279
1280 _dbus_assert (realign_root != NULL);
1281
1282 retval = FALSE;
1283
1284 if (!replacement_block_init (&block, reader))
1285 return FALSE;
1286
1287 /* Write the new basic value */
1288 #if RECURSIVE_MARSHAL_WRITE_TRACE
1289 _dbus_verbose ("INITIALIZING writer %p to write basic value at value_pos %d of replacement string\n",
1290 &writer, _dbus_string_get_length (&block.replacement));
1291 #endif
1292 _dbus_type_writer_init_values_only (&writer,
1293 reader->byte_order,
1294 reader->type_str,
1295 reader->type_pos,
1296 &block.replacement,
1297 _dbus_string_get_length (&block.replacement));
1298 #if RECURSIVE_MARSHAL_WRITE_TRACE
1299 _dbus_verbose ("WRITING basic value to writer %p (replacement string)\n", &writer);
1300 #endif
1301 if (!_dbus_type_writer_write_basic (&writer, current_type, value))
1302 goto out;
1303
1304 if (!replacement_block_replace (&block,
1305 reader,
1306 realign_root))
1307 goto out;
1308
1309 retval = TRUE;
1310
1311 out:
1312 replacement_block_free (&block);
1313 return retval;
1314 }
1315
1316 static void
reader_set_basic_fixed_length(DBusTypeReader * reader,int current_type,const void * value)1317 reader_set_basic_fixed_length (DBusTypeReader *reader,
1318 int current_type,
1319 const void *value)
1320 {
1321 _dbus_marshal_set_basic ((DBusString*) reader->value_str,
1322 reader->value_pos,
1323 current_type,
1324 value,
1325 reader->byte_order,
1326 NULL, NULL);
1327 }
1328
1329 /**
1330 * Sets a new value for the basic type value pointed to by the reader,
1331 * leaving the reader valid to continue reading. Any other readers
1332 * will be invalidated if you set a variable-length type such as a
1333 * string.
1334 *
1335 * The provided realign_root is the reader to start from when
1336 * realigning the data that follows the newly-set value. The reader
1337 * parameter must point to a value below the realign_root parameter.
1338 * If the type being set is fixed-length, then realign_root may be
1339 * #NULL. Only values reachable from realign_root will be realigned,
1340 * so if your string contains other values you will need to deal with
1341 * those somehow yourself. It is OK if realign_root is the same
1342 * reader as the reader parameter, though if you aren't setting the
1343 * root it may not be such a good idea.
1344 *
1345 * @todo DBusTypeReader currently takes "const" versions of the type
1346 * and value strings, and this function modifies those strings by
1347 * casting away the const, which is of course bad if we want to get
1348 * picky. (To be truly clean you'd have an object which contained the
1349 * type and value strings and set_basic would be a method on that
1350 * object... this would also make DBusTypeReader the same thing as
1351 * DBusTypeMark. But since DBusMessage is effectively that object for
1352 * D-Bus it doesn't seem worth creating some random object.)
1353 *
1354 * @todo optimize this by only rewriting until the old and new values
1355 * are at the same alignment. Frequently this should result in only
1356 * replacing the value that's immediately at hand.
1357 *
1358 * @param reader reader indicating where to set a new value
1359 * @param value address of the value to set
1360 * @param realign_root realign from here
1361 * @returns #FALSE if not enough memory
1362 */
1363 dbus_bool_t
_dbus_type_reader_set_basic(DBusTypeReader * reader,const void * value,const DBusTypeReader * realign_root)1364 _dbus_type_reader_set_basic (DBusTypeReader *reader,
1365 const void *value,
1366 const DBusTypeReader *realign_root)
1367 {
1368 int current_type;
1369
1370 _dbus_assert (!reader->klass->types_only);
1371 _dbus_assert (reader->value_str == realign_root->value_str);
1372 _dbus_assert (reader->value_pos >= realign_root->value_pos);
1373
1374 current_type = _dbus_type_reader_get_current_type (reader);
1375
1376 #if RECURSIVE_MARSHAL_WRITE_TRACE
1377 _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",
1378 reader, reader->type_pos, reader->value_pos,
1379 _dbus_string_get_const_data_len (reader->type_str, reader->type_pos, 0),
1380 realign_root,
1381 realign_root ? realign_root->value_pos : -1,
1382 _dbus_type_to_string (current_type));
1383 _dbus_verbose_bytes_of_string (realign_root->value_str, realign_root->value_pos,
1384 _dbus_string_get_length (realign_root->value_str) -
1385 realign_root->value_pos);
1386 #endif
1387
1388 _dbus_assert (dbus_type_is_basic (current_type));
1389
1390 if (dbus_type_is_fixed (current_type))
1391 {
1392 reader_set_basic_fixed_length (reader, current_type, value);
1393 return TRUE;
1394 }
1395 else
1396 {
1397 _dbus_assert (realign_root != NULL);
1398 return reader_set_basic_variable_length (reader, current_type,
1399 value, realign_root);
1400 }
1401 }
1402
1403 /**
1404 * Recursively deletes any value pointed to by the reader, leaving the
1405 * reader valid to continue reading. Any other readers will be
1406 * invalidated.
1407 *
1408 * The provided realign_root is the reader to start from when
1409 * realigning the data that follows the newly-set value.
1410 * See _dbus_type_reader_set_basic() for more details on the
1411 * realign_root paramter.
1412 *
1413 * @todo for now this does not delete the typecodes associated with
1414 * the value, so this function should only be used for array elements.
1415 *
1416 * @param reader reader indicating where to delete a value
1417 * @param realign_root realign from here
1418 * @returns #FALSE if not enough memory
1419 */
1420 dbus_bool_t
_dbus_type_reader_delete(DBusTypeReader * reader,const DBusTypeReader * realign_root)1421 _dbus_type_reader_delete (DBusTypeReader *reader,
1422 const DBusTypeReader *realign_root)
1423 {
1424 dbus_bool_t retval;
1425 ReplacementBlock block;
1426
1427 _dbus_assert (realign_root != NULL);
1428 _dbus_assert (reader->klass == &array_reader_class);
1429
1430 retval = FALSE;
1431
1432 if (!replacement_block_init (&block, reader))
1433 return FALSE;
1434
1435 if (!replacement_block_replace (&block,
1436 reader,
1437 realign_root))
1438 goto out;
1439
1440 retval = TRUE;
1441
1442 out:
1443 replacement_block_free (&block);
1444 return retval;
1445 }
1446
1447 /*
1448 * Compares two readers, which must be iterating over the same value data.
1449 * Returns #TRUE if the first parameter is further along than the second parameter.
1450 *
1451 * @param lhs left-hand-side (first) parameter
1452 * @param rhs left-hand-side (first) parameter
1453 * @returns whether lhs is greater than rhs
1454 */
1455 static dbus_bool_t
_dbus_type_reader_greater_than(const DBusTypeReader * lhs,const DBusTypeReader * rhs)1456 _dbus_type_reader_greater_than (const DBusTypeReader *lhs,
1457 const DBusTypeReader *rhs)
1458 {
1459 _dbus_assert (lhs->value_str == rhs->value_str);
1460
1461 return lhs->value_pos > rhs->value_pos;
1462 }
1463
1464 /*
1465 *
1466 *
1467 * DBusTypeWriter
1468 *
1469 *
1470 *
1471 */
1472
1473 /**
1474 * Initialize a write iterator, which is used to write out values in
1475 * serialized D-Bus format.
1476 *
1477 * The type_pos passed in is expected to be inside an already-valid,
1478 * though potentially empty, type signature. This means that the byte
1479 * after type_pos must be either #DBUS_TYPE_INVALID (aka nul) or some
1480 * other valid type. #DBusTypeWriter won't enforce that the signature
1481 * is already valid (you can append the nul byte at the end if you
1482 * like), but just be aware that you need the nul byte eventually and
1483 * #DBusTypeWriter isn't going to write it for you.
1484 *
1485 * @param writer the writer to init
1486 * @param byte_order the byte order to marshal into
1487 * @param type_str the string to write typecodes into
1488 * @param type_pos where to insert typecodes
1489 * @param value_str the string to write values into
1490 * @param value_pos where to insert values
1491 *
1492 */
1493 void
_dbus_type_writer_init(DBusTypeWriter * writer,int byte_order,DBusString * type_str,int type_pos,DBusString * value_str,int value_pos)1494 _dbus_type_writer_init (DBusTypeWriter *writer,
1495 int byte_order,
1496 DBusString *type_str,
1497 int type_pos,
1498 DBusString *value_str,
1499 int value_pos)
1500 {
1501 writer->byte_order = byte_order;
1502 writer->type_str = type_str;
1503 writer->type_pos = type_pos;
1504 writer->value_str = value_str;
1505 writer->value_pos = value_pos;
1506 writer->container_type = DBUS_TYPE_INVALID;
1507 writer->type_pos_is_expectation = FALSE;
1508 writer->enabled = TRUE;
1509
1510 #if RECURSIVE_MARSHAL_WRITE_TRACE
1511 _dbus_verbose ("writer %p init remaining sig '%s'\n", writer,
1512 writer->type_str ?
1513 _dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
1514 "unknown");
1515 #endif
1516 }
1517
1518 /**
1519 * Initialize a write iterator, with the signature to be provided
1520 * later.
1521 *
1522 * @param writer the writer to init
1523 * @param byte_order the byte order to marshal into
1524 * @param value_str the string to write values into
1525 * @param value_pos where to insert values
1526 *
1527 */
1528 void
_dbus_type_writer_init_types_delayed(DBusTypeWriter * writer,int byte_order,DBusString * value_str,int value_pos)1529 _dbus_type_writer_init_types_delayed (DBusTypeWriter *writer,
1530 int byte_order,
1531 DBusString *value_str,
1532 int value_pos)
1533 {
1534 _dbus_type_writer_init (writer, byte_order,
1535 NULL, 0, value_str, value_pos);
1536 }
1537
1538 /**
1539 * Adds type string to the writer, if it had none.
1540 *
1541 * @param writer the writer to init
1542 * @param type_str type string to add
1543 * @param type_pos type position
1544 *
1545 */
1546 void
_dbus_type_writer_add_types(DBusTypeWriter * writer,DBusString * type_str,int type_pos)1547 _dbus_type_writer_add_types (DBusTypeWriter *writer,
1548 DBusString *type_str,
1549 int type_pos)
1550 {
1551 if (writer->type_str == NULL) /* keeps us from using this as setter */
1552 {
1553 writer->type_str = type_str;
1554 writer->type_pos = type_pos;
1555 }
1556 }
1557
1558 /**
1559 * Removes type string from the writer.
1560 *
1561 * @param writer the writer to remove from
1562 */
1563 void
_dbus_type_writer_remove_types(DBusTypeWriter * writer)1564 _dbus_type_writer_remove_types (DBusTypeWriter *writer)
1565 {
1566 writer->type_str = NULL;
1567 writer->type_pos = -1;
1568 }
1569
1570 /**
1571 * Like _dbus_type_writer_init(), except the type string
1572 * passed in should correspond to an existing signature that
1573 * matches what you're going to write out. The writer will
1574 * check what you write vs. this existing signature.
1575 *
1576 * @param writer the writer to init
1577 * @param byte_order the byte order to marshal into
1578 * @param type_str the string with signature
1579 * @param type_pos start of signature
1580 * @param value_str the string to write values into
1581 * @param value_pos where to insert values
1582 *
1583 */
1584 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)1585 _dbus_type_writer_init_values_only (DBusTypeWriter *writer,
1586 int byte_order,
1587 const DBusString *type_str,
1588 int type_pos,
1589 DBusString *value_str,
1590 int value_pos)
1591 {
1592 _dbus_type_writer_init (writer, byte_order,
1593 (DBusString*)type_str, type_pos,
1594 value_str, value_pos);
1595
1596 writer->type_pos_is_expectation = TRUE;
1597 }
1598
1599 static dbus_bool_t
_dbus_type_writer_write_basic_no_typecode(DBusTypeWriter * writer,int type,const void * value)1600 _dbus_type_writer_write_basic_no_typecode (DBusTypeWriter *writer,
1601 int type,
1602 const void *value)
1603 {
1604 if (writer->enabled)
1605 return _dbus_marshal_write_basic (writer->value_str,
1606 writer->value_pos,
1607 type,
1608 value,
1609 writer->byte_order,
1610 &writer->value_pos);
1611 else
1612 return TRUE;
1613 }
1614
1615 /* If our parent is an array, things are a little bit complicated.
1616 *
1617 * The parent must have a complete element type, such as
1618 * "i" or "aai" or "(ii)" or "a(ii)". There can't be
1619 * unclosed parens, or an "a" with no following type.
1620 *
1621 * To recurse, the only allowed operation is to recurse into the
1622 * first type in the element type. So for "i" you can't recurse, for
1623 * "ai" you can recurse into the array, for "(ii)" you can recurse
1624 * into the struct.
1625 *
1626 * If you recurse into the array for "ai", then you must specify
1627 * "i" for the element type of the array you recurse into.
1628 *
1629 * While inside an array at any level, we need to avoid writing to
1630 * type_str, since the type only appears once for the whole array,
1631 * it does not appear for each array element.
1632 *
1633 * While inside an array type_pos points to the expected next
1634 * typecode, rather than the next place we could write a typecode.
1635 */
1636 static void
writer_recurse_init_and_check(DBusTypeWriter * writer,int container_type,DBusTypeWriter * sub)1637 writer_recurse_init_and_check (DBusTypeWriter *writer,
1638 int container_type,
1639 DBusTypeWriter *sub)
1640 {
1641 _dbus_type_writer_init (sub,
1642 writer->byte_order,
1643 writer->type_str,
1644 writer->type_pos,
1645 writer->value_str,
1646 writer->value_pos);
1647
1648 sub->container_type = container_type;
1649
1650 if (writer->type_pos_is_expectation ||
1651 (sub->container_type == DBUS_TYPE_ARRAY || sub->container_type == DBUS_TYPE_VARIANT))
1652 sub->type_pos_is_expectation = TRUE;
1653 else
1654 sub->type_pos_is_expectation = FALSE;
1655
1656 sub->enabled = writer->enabled;
1657
1658 #ifndef DBUS_DISABLE_CHECKS
1659 if (writer->type_pos_is_expectation && writer->type_str)
1660 {
1661 int expected;
1662
1663 expected = _dbus_first_type_in_signature (writer->type_str, writer->type_pos);
1664
1665 if (expected != sub->container_type)
1666 {
1667 if (expected != DBUS_TYPE_INVALID)
1668 _dbus_warn_check_failed ("Writing an element of type %s, but the expected type here is %s\n"
1669 "The overall signature expected here was '%s' and we are on byte %d of that signature.",
1670 _dbus_type_to_string (sub->container_type),
1671 _dbus_type_to_string (expected),
1672 _dbus_string_get_const_data (writer->type_str), writer->type_pos);
1673 else
1674 _dbus_warn_check_failed ("Writing an element of type %s, but no value is expected here\n"
1675 "The overall signature expected here was '%s' and we are on byte %d of that signature.",
1676 _dbus_type_to_string (sub->container_type),
1677 _dbus_string_get_const_data (writer->type_str), writer->type_pos);
1678
1679 _dbus_assert_not_reached ("bad array element or variant content written");
1680 }
1681 }
1682 #endif /* DBUS_DISABLE_CHECKS */
1683
1684 #if RECURSIVE_MARSHAL_WRITE_TRACE
1685 _dbus_verbose (" type writer %p recurse parent %s type_pos = %d value_pos = %d is_expectation = %d remaining sig '%s' enabled = %d\n",
1686 writer,
1687 _dbus_type_to_string (writer->container_type),
1688 writer->type_pos, writer->value_pos, writer->type_pos_is_expectation,
1689 writer->type_str ?
1690 _dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
1691 "unknown",
1692 writer->enabled);
1693 _dbus_verbose (" type writer %p recurse sub %s type_pos = %d value_pos = %d is_expectation = %d enabled = %d\n",
1694 sub,
1695 _dbus_type_to_string (sub->container_type),
1696 sub->type_pos, sub->value_pos,
1697 sub->type_pos_is_expectation,
1698 sub->enabled);
1699 #endif
1700 }
1701
1702 static dbus_bool_t
write_or_verify_typecode(DBusTypeWriter * writer,int typecode)1703 write_or_verify_typecode (DBusTypeWriter *writer,
1704 int typecode)
1705 {
1706 /* A subwriter inside an array or variant will have type_pos
1707 * pointing to the expected typecode; a writer not inside an array
1708 * or variant has type_pos pointing to the next place to insert a
1709 * typecode.
1710 */
1711 #if RECURSIVE_MARSHAL_WRITE_TRACE
1712 _dbus_verbose (" type writer %p write_or_verify start type_pos = %d remaining sig '%s' enabled = %d\n",
1713 writer, writer->type_pos,
1714 writer->type_str ?
1715 _dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
1716 "unknown",
1717 writer->enabled);
1718 #endif
1719
1720 if (writer->type_str == NULL)
1721 return TRUE;
1722
1723 if (writer->type_pos_is_expectation)
1724 {
1725 #ifndef DBUS_DISABLE_CHECKS
1726 {
1727 int expected;
1728
1729 expected = _dbus_string_get_byte (writer->type_str, writer->type_pos);
1730
1731 if (expected != typecode)
1732 {
1733 if (expected != DBUS_TYPE_INVALID)
1734 _dbus_warn_check_failed ("Array or variant type requires that type %s be written, but %s was written.\n"
1735 "The overall signature expected here was '%s' and we are on byte %d of that signature.",
1736 _dbus_type_to_string (expected), _dbus_type_to_string (typecode),
1737 _dbus_string_get_const_data (writer->type_str), writer->type_pos);
1738 else
1739 _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"
1740 "The overall signature expected here was '%s' and we are on byte %d of that signature.",
1741 _dbus_type_to_string (typecode),
1742 _dbus_string_get_const_data (writer->type_str), writer->type_pos);
1743 _dbus_assert_not_reached ("bad type inserted somewhere inside an array or variant");
1744 }
1745 }
1746 #endif /* DBUS_DISABLE_CHECKS */
1747
1748 /* if immediately inside an array we'd always be appending an element,
1749 * so the expected type doesn't change; if inside a struct or something
1750 * below an array, we need to move through said struct or something.
1751 */
1752 if (writer->container_type != DBUS_TYPE_ARRAY)
1753 writer->type_pos += 1;
1754 }
1755 else
1756 {
1757 if (!_dbus_string_insert_byte (writer->type_str,
1758 writer->type_pos,
1759 typecode))
1760 return FALSE;
1761
1762 writer->type_pos += 1;
1763 }
1764
1765 #if RECURSIVE_MARSHAL_WRITE_TRACE
1766 _dbus_verbose (" type writer %p write_or_verify end type_pos = %d remaining sig '%s'\n",
1767 writer, writer->type_pos,
1768 _dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0));
1769 #endif
1770
1771 return TRUE;
1772 }
1773
1774 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)1775 writer_recurse_struct_or_dict_entry (DBusTypeWriter *writer,
1776 int begin_char,
1777 const DBusString *contained_type,
1778 int contained_type_start,
1779 int contained_type_len,
1780 DBusTypeWriter *sub)
1781 {
1782 /* FIXME right now contained_type is ignored; we could probably
1783 * almost trivially fix the code so if it's present we
1784 * write it out and then set type_pos_is_expectation
1785 */
1786
1787 /* Ensure that we'll be able to add alignment padding and the typecode */
1788 if (writer->enabled)
1789 {
1790 if (!_dbus_string_alloc_space (sub->value_str, 8))
1791 return FALSE;
1792 }
1793
1794 if (!write_or_verify_typecode (sub, begin_char))
1795 _dbus_assert_not_reached ("failed to insert struct typecode after prealloc");
1796
1797 if (writer->enabled)
1798 {
1799 if (!_dbus_string_insert_bytes (sub->value_str,
1800 sub->value_pos,
1801 _DBUS_ALIGN_VALUE (sub->value_pos, 8) - sub->value_pos,
1802 '\0'))
1803 _dbus_assert_not_reached ("should not have failed to insert alignment padding for struct");
1804 sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 8);
1805 }
1806
1807 return TRUE;
1808 }
1809
1810
1811 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)1812 writer_recurse_array (DBusTypeWriter *writer,
1813 const DBusString *contained_type,
1814 int contained_type_start,
1815 int contained_type_len,
1816 DBusTypeWriter *sub,
1817 dbus_bool_t is_array_append)
1818 {
1819 dbus_uint32_t value = 0;
1820 int alignment;
1821 int aligned;
1822
1823 #ifndef DBUS_DISABLE_CHECKS
1824 if (writer->container_type == DBUS_TYPE_ARRAY &&
1825 writer->type_str)
1826 {
1827 if (!_dbus_string_equal_substring (contained_type,
1828 contained_type_start,
1829 contained_type_len,
1830 writer->type_str,
1831 writer->u.array.element_type_pos + 1))
1832 {
1833 _dbus_warn_check_failed ("Writing an array of '%s' but this is incompatible with the expected type of elements in the parent array",
1834 _dbus_string_get_const_data_len (contained_type,
1835 contained_type_start,
1836 contained_type_len));
1837 _dbus_assert_not_reached ("incompatible type for child array");
1838 }
1839 }
1840 #endif /* DBUS_DISABLE_CHECKS */
1841
1842 if (writer->enabled && !is_array_append)
1843 {
1844 /* 3 pad + 4 bytes for the array length, and 4 bytes possible padding
1845 * before array values
1846 */
1847 if (!_dbus_string_alloc_space (sub->value_str, 3 + 4 + 4))
1848 return FALSE;
1849 }
1850
1851 if (writer->type_str != NULL)
1852 {
1853 sub->type_pos += 1; /* move to point to the element type, since type_pos
1854 * should be the expected type for further writes
1855 */
1856 sub->u.array.element_type_pos = sub->type_pos;
1857 }
1858
1859 if (!writer->type_pos_is_expectation)
1860 {
1861 /* sub is a toplevel/outermost array so we need to write the type data */
1862
1863 /* alloc space for array typecode, element signature */
1864 if (!_dbus_string_alloc_space (writer->type_str, 1 + contained_type_len))
1865 return FALSE;
1866
1867 if (!_dbus_string_insert_byte (writer->type_str,
1868 writer->type_pos,
1869 DBUS_TYPE_ARRAY))
1870 _dbus_assert_not_reached ("failed to insert array typecode after prealloc");
1871
1872 if (!_dbus_string_copy_len (contained_type,
1873 contained_type_start, contained_type_len,
1874 sub->type_str,
1875 sub->u.array.element_type_pos))
1876 _dbus_assert_not_reached ("should not have failed to insert array element typecodes");
1877 }
1878
1879 if (writer->type_str != NULL)
1880 {
1881 /* If the parent is an array, we hold type_pos pointing at the array element type;
1882 * otherwise advance it to reflect the array value we just recursed into
1883 */
1884 if (writer->container_type != DBUS_TYPE_ARRAY)
1885 writer->type_pos += 1 + contained_type_len;
1886 else
1887 _dbus_assert (writer->type_pos_is_expectation); /* because it's an array */
1888 }
1889
1890 if (writer->enabled)
1891 {
1892 /* Write (or jump over, if is_array_append) the length */
1893 sub->u.array.len_pos = _DBUS_ALIGN_VALUE (sub->value_pos, 4);
1894
1895 if (is_array_append)
1896 {
1897 sub->value_pos += 4;
1898 }
1899 else
1900 {
1901 if (!_dbus_type_writer_write_basic_no_typecode (sub, DBUS_TYPE_UINT32,
1902 &value))
1903 _dbus_assert_not_reached ("should not have failed to insert array len");
1904 }
1905
1906 _dbus_assert (sub->u.array.len_pos == sub->value_pos - 4);
1907
1908 /* Write alignment padding for array elements
1909 * Note that we write the padding *even for empty arrays*
1910 * to avoid wonky special cases
1911 */
1912 alignment = element_type_get_alignment (contained_type, contained_type_start);
1913
1914 aligned = _DBUS_ALIGN_VALUE (sub->value_pos, alignment);
1915 if (aligned != sub->value_pos)
1916 {
1917 if (!is_array_append)
1918 {
1919 if (!_dbus_string_insert_bytes (sub->value_str,
1920 sub->value_pos,
1921 aligned - sub->value_pos,
1922 '\0'))
1923 _dbus_assert_not_reached ("should not have failed to insert alignment padding");
1924 }
1925
1926 sub->value_pos = aligned;
1927 }
1928
1929 sub->u.array.start_pos = sub->value_pos;
1930
1931 if (is_array_append)
1932 {
1933 dbus_uint32_t len;
1934
1935 _dbus_assert (_DBUS_ALIGN_VALUE (sub->u.array.len_pos, 4) ==
1936 (unsigned) sub->u.array.len_pos);
1937 len = _dbus_unpack_uint32 (sub->byte_order,
1938 _dbus_string_get_const_udata_len (sub->value_str,
1939 sub->u.array.len_pos,
1940 4));
1941
1942 sub->value_pos += len;
1943 }
1944 }
1945 else
1946 {
1947 /* not enabled, so we won't write the len_pos; set it to -1 to so indicate */
1948 sub->u.array.len_pos = -1;
1949 sub->u.array.start_pos = sub->value_pos;
1950 }
1951
1952 _dbus_assert (sub->u.array.len_pos < sub->u.array.start_pos);
1953 _dbus_assert (is_array_append || sub->u.array.start_pos == sub->value_pos);
1954
1955 #if RECURSIVE_MARSHAL_WRITE_TRACE
1956 _dbus_verbose (" type writer %p recurse array done remaining sig '%s' array start_pos = %d len_pos = %d value_pos = %d\n", sub,
1957 sub->type_str ?
1958 _dbus_string_get_const_data_len (sub->type_str, sub->type_pos, 0) :
1959 "unknown",
1960 sub->u.array.start_pos, sub->u.array.len_pos, sub->value_pos);
1961 #endif
1962
1963 return TRUE;
1964 }
1965
1966 /* Variant value will normally have:
1967 * 1 byte signature length not including nul
1968 * signature typecodes (nul terminated)
1969 * padding to alignment of contained type
1970 * body according to signature
1971 *
1972 * The signature string can only have a single type
1973 * in it but that type may be complex/recursive.
1974 *
1975 * So a typical variant type with the integer 3 will have these
1976 * octets:
1977 * 0x1 'i' '\0' [1 byte padding to alignment boundary] 0x0 0x0 0x0 0x3
1978 *
1979 * The main world of hurt for writing out a variant is that the type
1980 * string is the same string as the value string. Which means
1981 * inserting to the type string will move the value_pos; and it means
1982 * that inserting to the type string could break type alignment.
1983 */
1984 static dbus_bool_t
writer_recurse_variant(DBusTypeWriter * writer,const DBusString * contained_type,int contained_type_start,int contained_type_len,DBusTypeWriter * sub)1985 writer_recurse_variant (DBusTypeWriter *writer,
1986 const DBusString *contained_type,
1987 int contained_type_start,
1988 int contained_type_len,
1989 DBusTypeWriter *sub)
1990 {
1991 int contained_alignment;
1992
1993 if (writer->enabled)
1994 {
1995 /* Allocate space for the worst case, which is 1 byte sig
1996 * length, nul byte at end of sig, and 7 bytes padding to
1997 * 8-boundary.
1998 */
1999 if (!_dbus_string_alloc_space (sub->value_str, contained_type_len + 9))
2000 return FALSE;
2001 }
2002
2003 /* write VARIANT typecode to the parent's type string */
2004 if (!write_or_verify_typecode (writer, DBUS_TYPE_VARIANT))
2005 return FALSE;
2006
2007 /* If not enabled, mark that we have no type_str anymore ... */
2008
2009 if (!writer->enabled)
2010 {
2011 sub->type_str = NULL;
2012 sub->type_pos = -1;
2013
2014 return TRUE;
2015 }
2016
2017 /* If we're enabled then continue ... */
2018
2019 if (!_dbus_string_insert_byte (sub->value_str,
2020 sub->value_pos,
2021 contained_type_len))
2022 _dbus_assert_not_reached ("should not have failed to insert variant type sig len");
2023
2024 sub->value_pos += 1;
2025
2026 /* Here we switch over to the expected type sig we're about to write */
2027 sub->type_str = sub->value_str;
2028 sub->type_pos = sub->value_pos;
2029
2030 if (!_dbus_string_copy_len (contained_type, contained_type_start, contained_type_len,
2031 sub->value_str, sub->value_pos))
2032 _dbus_assert_not_reached ("should not have failed to insert variant type sig");
2033
2034 sub->value_pos += contained_type_len;
2035
2036 if (!_dbus_string_insert_byte (sub->value_str,
2037 sub->value_pos,
2038 DBUS_TYPE_INVALID))
2039 _dbus_assert_not_reached ("should not have failed to insert variant type nul termination");
2040
2041 sub->value_pos += 1;
2042
2043 contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (contained_type, contained_type_start));
2044
2045 if (!_dbus_string_insert_bytes (sub->value_str,
2046 sub->value_pos,
2047 _DBUS_ALIGN_VALUE (sub->value_pos, contained_alignment) - sub->value_pos,
2048 '\0'))
2049 _dbus_assert_not_reached ("should not have failed to insert alignment padding for variant body");
2050 sub->value_pos = _DBUS_ALIGN_VALUE (sub->value_pos, contained_alignment);
2051
2052 return TRUE;
2053 }
2054
2055 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)2056 _dbus_type_writer_recurse_contained_len (DBusTypeWriter *writer,
2057 int container_type,
2058 const DBusString *contained_type,
2059 int contained_type_start,
2060 int contained_type_len,
2061 DBusTypeWriter *sub,
2062 dbus_bool_t is_array_append)
2063 {
2064 writer_recurse_init_and_check (writer, container_type, sub);
2065
2066 switch (container_type)
2067 {
2068 case DBUS_TYPE_STRUCT:
2069 return writer_recurse_struct_or_dict_entry (writer,
2070 DBUS_STRUCT_BEGIN_CHAR,
2071 contained_type,
2072 contained_type_start, contained_type_len,
2073 sub);
2074 break;
2075 case DBUS_TYPE_DICT_ENTRY:
2076 return writer_recurse_struct_or_dict_entry (writer,
2077 DBUS_DICT_ENTRY_BEGIN_CHAR,
2078 contained_type,
2079 contained_type_start, contained_type_len,
2080 sub);
2081 break;
2082 case DBUS_TYPE_ARRAY:
2083 return writer_recurse_array (writer,
2084 contained_type, contained_type_start, contained_type_len,
2085 sub, is_array_append);
2086 break;
2087 case DBUS_TYPE_VARIANT:
2088 return writer_recurse_variant (writer,
2089 contained_type, contained_type_start, contained_type_len,
2090 sub);
2091 break;
2092 default:
2093 _dbus_assert_not_reached ("tried to recurse into type that doesn't support that");
2094 return FALSE;
2095 break;
2096 }
2097 }
2098
2099 /**
2100 * Opens a new container and writes out the initial information for that container.
2101 *
2102 * @param writer the writer
2103 * @param container_type the type of the container to open
2104 * @param contained_type the array element type or variant content type
2105 * @param contained_type_start position to look for the type
2106 * @param sub the new sub-writer to write container contents
2107 * @returns #FALSE if no memory
2108 */
2109 dbus_bool_t
_dbus_type_writer_recurse(DBusTypeWriter * writer,int container_type,const DBusString * contained_type,int contained_type_start,DBusTypeWriter * sub)2110 _dbus_type_writer_recurse (DBusTypeWriter *writer,
2111 int container_type,
2112 const DBusString *contained_type,
2113 int contained_type_start,
2114 DBusTypeWriter *sub)
2115 {
2116 int contained_type_len;
2117
2118 if (contained_type)
2119 contained_type_len = find_len_of_complete_type (contained_type, contained_type_start);
2120 else
2121 contained_type_len = 0;
2122
2123 return _dbus_type_writer_recurse_contained_len (writer, container_type,
2124 contained_type,
2125 contained_type_start,
2126 contained_type_len,
2127 sub,
2128 FALSE);
2129 }
2130
2131 /**
2132 * Append to an existing array. Essentially, the writer will read an
2133 * existing length at the write location; jump over that length; and
2134 * write new fields. On unrecurse(), the existing length will be
2135 * updated.
2136 *
2137 * @param writer the writer
2138 * @param contained_type element type
2139 * @param contained_type_start position of element type
2140 * @param sub the subwriter to init
2141 * @returns #FALSE if no memory
2142 */
2143 dbus_bool_t
_dbus_type_writer_append_array(DBusTypeWriter * writer,const DBusString * contained_type,int contained_type_start,DBusTypeWriter * sub)2144 _dbus_type_writer_append_array (DBusTypeWriter *writer,
2145 const DBusString *contained_type,
2146 int contained_type_start,
2147 DBusTypeWriter *sub)
2148 {
2149 int contained_type_len;
2150
2151 if (contained_type)
2152 contained_type_len = find_len_of_complete_type (contained_type, contained_type_start);
2153 else
2154 contained_type_len = 0;
2155
2156 return _dbus_type_writer_recurse_contained_len (writer, DBUS_TYPE_ARRAY,
2157 contained_type,
2158 contained_type_start,
2159 contained_type_len,
2160 sub,
2161 TRUE);
2162 }
2163
2164 static int
writer_get_array_len(DBusTypeWriter * writer)2165 writer_get_array_len (DBusTypeWriter *writer)
2166 {
2167 _dbus_assert (writer->container_type == DBUS_TYPE_ARRAY);
2168 return writer->value_pos - writer->u.array.start_pos;
2169 }
2170
2171 /**
2172 * Closes a container created by _dbus_type_writer_recurse()
2173 * and writes any additional information to the values block.
2174 *
2175 * @param writer the writer
2176 * @param sub the sub-writer created by _dbus_type_writer_recurse()
2177 * @returns #FALSE if no memory
2178 */
2179 dbus_bool_t
_dbus_type_writer_unrecurse(DBusTypeWriter * writer,DBusTypeWriter * sub)2180 _dbus_type_writer_unrecurse (DBusTypeWriter *writer,
2181 DBusTypeWriter *sub)
2182 {
2183 /* type_pos_is_expectation never gets unset once set, or we'd get all hosed */
2184 _dbus_assert (!writer->type_pos_is_expectation ||
2185 (writer->type_pos_is_expectation && sub->type_pos_is_expectation));
2186
2187 #if RECURSIVE_MARSHAL_WRITE_TRACE
2188 _dbus_verbose (" type writer %p unrecurse type_pos = %d value_pos = %d is_expectation = %d container_type = %s\n",
2189 writer, writer->type_pos, writer->value_pos, writer->type_pos_is_expectation,
2190 _dbus_type_to_string (writer->container_type));
2191 _dbus_verbose (" type writer %p unrecurse sub type_pos = %d value_pos = %d is_expectation = %d container_type = %s\n",
2192 sub, sub->type_pos, sub->value_pos,
2193 sub->type_pos_is_expectation,
2194 _dbus_type_to_string (sub->container_type));
2195 #endif
2196
2197 if (sub->container_type == DBUS_TYPE_STRUCT)
2198 {
2199 if (!write_or_verify_typecode (sub, DBUS_STRUCT_END_CHAR))
2200 return FALSE;
2201 }
2202 else if (sub->container_type == DBUS_TYPE_DICT_ENTRY)
2203 {
2204 if (!write_or_verify_typecode (sub, DBUS_DICT_ENTRY_END_CHAR))
2205 return FALSE;
2206 }
2207 else if (sub->container_type == DBUS_TYPE_ARRAY)
2208 {
2209 if (sub->u.array.len_pos >= 0) /* len_pos == -1 if we weren't enabled when we passed it */
2210 {
2211 dbus_uint32_t len;
2212
2213 /* Set the array length */
2214 len = writer_get_array_len (sub);
2215 _dbus_marshal_set_uint32 (sub->value_str,
2216 sub->u.array.len_pos,
2217 len,
2218 sub->byte_order);
2219 #if RECURSIVE_MARSHAL_WRITE_TRACE
2220 _dbus_verbose (" filled in sub array len to %u at len_pos %d\n",
2221 len, sub->u.array.len_pos);
2222 #endif
2223 }
2224 #if RECURSIVE_MARSHAL_WRITE_TRACE
2225 else
2226 {
2227 _dbus_verbose (" not filling in sub array len because we were disabled when we passed the len\n");
2228 }
2229 #endif
2230 }
2231
2232 /* Now get type_pos right for the parent writer. Here are the cases:
2233 *
2234 * Cases !writer->type_pos_is_expectation:
2235 * (in these cases we want to update to the new insertion point)
2236 *
2237 * - if we recursed into a STRUCT then we didn't know in advance
2238 * what the types in the struct would be; so we have to fill in
2239 * that information now.
2240 * writer->type_pos = sub->type_pos
2241 *
2242 * - if we recursed into anything else, we knew the full array
2243 * type, or knew the single typecode marking VARIANT, so
2244 * writer->type_pos is already correct.
2245 * writer->type_pos should remain as-is
2246 *
2247 * - note that the parent is never an ARRAY or VARIANT, if it were
2248 * then type_pos_is_expectation would be TRUE. The parent
2249 * is thus known to be a toplevel or STRUCT.
2250 *
2251 * Cases where writer->type_pos_is_expectation:
2252 * (in these cases we want to update to next expected type to write)
2253 *
2254 * - we recursed from STRUCT into STRUCT and we didn't increment
2255 * type_pos in the parent just to stay consistent with the
2256 * !writer->type_pos_is_expectation case (though we could
2257 * special-case this in recurse_struct instead if we wanted)
2258 * writer->type_pos = sub->type_pos
2259 *
2260 * - we recursed from STRUCT into ARRAY or VARIANT and type_pos
2261 * for parent should have been incremented already
2262 * writer->type_pos should remain as-is
2263 *
2264 * - we recursed from ARRAY into a sub-element, so type_pos in the
2265 * parent is the element type and should remain the element type
2266 * for the benefit of the next child element
2267 * writer->type_pos should remain as-is
2268 *
2269 * - we recursed from VARIANT into its value, so type_pos in the
2270 * parent makes no difference since there's only one value
2271 * and we just finished writing it and won't use type_pos again
2272 * writer->type_pos should remain as-is
2273 *
2274 *
2275 * For all these, DICT_ENTRY is the same as STRUCT
2276 */
2277 if (writer->type_str != NULL)
2278 {
2279 if ((sub->container_type == DBUS_TYPE_STRUCT ||
2280 sub->container_type == DBUS_TYPE_DICT_ENTRY) &&
2281 (writer->container_type == DBUS_TYPE_STRUCT ||
2282 writer->container_type == DBUS_TYPE_DICT_ENTRY ||
2283 writer->container_type == DBUS_TYPE_INVALID))
2284 {
2285 /* Advance the parent to the next struct field */
2286 writer->type_pos = sub->type_pos;
2287 }
2288 }
2289
2290 writer->value_pos = sub->value_pos;
2291
2292 #if RECURSIVE_MARSHAL_WRITE_TRACE
2293 _dbus_verbose (" type writer %p unrecursed type_pos = %d value_pos = %d remaining sig '%s'\n",
2294 writer, writer->type_pos, writer->value_pos,
2295 writer->type_str ?
2296 _dbus_string_get_const_data_len (writer->type_str, writer->type_pos, 0) :
2297 "unknown");
2298 #endif
2299
2300 return TRUE;
2301 }
2302
2303 /**
2304 * Writes out a basic type.
2305 *
2306 * @param writer the writer
2307 * @param type the type to write
2308 * @param value the address of the value to write
2309 * @returns #FALSE if no memory
2310 */
2311 dbus_bool_t
_dbus_type_writer_write_basic(DBusTypeWriter * writer,int type,const void * value)2312 _dbus_type_writer_write_basic (DBusTypeWriter *writer,
2313 int type,
2314 const void *value)
2315 {
2316 dbus_bool_t retval;
2317
2318 /* First ensure that our type realloc will succeed */
2319 if (!writer->type_pos_is_expectation && writer->type_str != NULL)
2320 {
2321 if (!_dbus_string_alloc_space (writer->type_str, 1))
2322 return FALSE;
2323 }
2324
2325 retval = FALSE;
2326
2327 if (!_dbus_type_writer_write_basic_no_typecode (writer, type, value))
2328 goto out;
2329
2330 if (!write_or_verify_typecode (writer, type))
2331 _dbus_assert_not_reached ("failed to write typecode after prealloc");
2332
2333 retval = TRUE;
2334
2335 out:
2336 #if RECURSIVE_MARSHAL_WRITE_TRACE
2337 _dbus_verbose (" type writer %p basic type_pos = %d value_pos = %d is_expectation = %d enabled = %d\n",
2338 writer, writer->type_pos, writer->value_pos, writer->type_pos_is_expectation,
2339 writer->enabled);
2340 #endif
2341
2342 return retval;
2343 }
2344
2345 /**
2346 * Writes a block of fixed-length basic values, i.e. those that are
2347 * both dbus_type_is_fixed() and _dbus_type_is_basic(). The block
2348 * must be written inside an array.
2349 *
2350 * The value parameter should be the address of said array of values,
2351 * so e.g. if it's an array of double, pass in "const double**"
2352 *
2353 * @param writer the writer
2354 * @param element_type type of stuff in the array
2355 * @param value address of the array
2356 * @param n_elements number of elements in the array
2357 * @returns #FALSE if no memory
2358 */
2359 dbus_bool_t
_dbus_type_writer_write_fixed_multi(DBusTypeWriter * writer,int element_type,const void * value,int n_elements)2360 _dbus_type_writer_write_fixed_multi (DBusTypeWriter *writer,
2361 int element_type,
2362 const void *value,
2363 int n_elements)
2364 {
2365 _dbus_assert (writer->container_type == DBUS_TYPE_ARRAY);
2366 _dbus_assert (dbus_type_is_fixed (element_type));
2367 _dbus_assert (writer->type_pos_is_expectation);
2368 _dbus_assert (n_elements >= 0);
2369
2370 #if RECURSIVE_MARSHAL_WRITE_TRACE
2371 _dbus_verbose (" type writer %p entering fixed multi type_pos = %d value_pos = %d n_elements %d\n",
2372 writer, writer->type_pos, writer->value_pos, n_elements);
2373 #endif
2374
2375 if (!write_or_verify_typecode (writer, element_type))
2376 _dbus_assert_not_reached ("OOM should not happen if only verifying typecode");
2377
2378 if (writer->enabled)
2379 {
2380 if (!_dbus_marshal_write_fixed_multi (writer->value_str,
2381 writer->value_pos,
2382 element_type,
2383 value,
2384 n_elements,
2385 writer->byte_order,
2386 &writer->value_pos))
2387 return FALSE;
2388 }
2389
2390 #if RECURSIVE_MARSHAL_WRITE_TRACE
2391 _dbus_verbose (" type writer %p fixed multi written new type_pos = %d new value_pos = %d n_elements %d\n",
2392 writer, writer->type_pos, writer->value_pos, n_elements);
2393 #endif
2394
2395 return TRUE;
2396 }
2397
2398 static void
enable_if_after(DBusTypeWriter * writer,DBusTypeReader * reader,const DBusTypeReader * start_after)2399 enable_if_after (DBusTypeWriter *writer,
2400 DBusTypeReader *reader,
2401 const DBusTypeReader *start_after)
2402 {
2403 if (start_after)
2404 {
2405 if (!writer->enabled && _dbus_type_reader_greater_than (reader, start_after))
2406 {
2407 _dbus_type_writer_set_enabled (writer, TRUE);
2408 #if RECURSIVE_MARSHAL_WRITE_TRACE
2409 _dbus_verbose ("ENABLING writer %p at %d because reader at value_pos %d is after reader at value_pos %d\n",
2410 writer, writer->value_pos, reader->value_pos, start_after->value_pos);
2411 #endif
2412 }
2413
2414 _dbus_assert ((!writer->enabled && !_dbus_type_reader_greater_than (reader, start_after)) ||
2415 (writer->enabled && _dbus_type_reader_greater_than (reader, start_after)));
2416 }
2417 }
2418
2419 static dbus_bool_t
append_fixup(DBusList ** fixups,const DBusArrayLenFixup * fixup)2420 append_fixup (DBusList **fixups,
2421 const DBusArrayLenFixup *fixup)
2422 {
2423 DBusArrayLenFixup *f;
2424
2425 f = dbus_new (DBusArrayLenFixup, 1);
2426 if (f == NULL)
2427 return FALSE;
2428
2429 *f = *fixup;
2430
2431 if (!_dbus_list_append (fixups, f))
2432 {
2433 dbus_free (f);
2434 return FALSE;
2435 }
2436
2437 _dbus_assert (f->len_pos_in_reader == fixup->len_pos_in_reader);
2438 _dbus_assert (f->new_len == fixup->new_len);
2439
2440 return TRUE;
2441 }
2442
2443 /* This loop is trivial if you ignore all the start_after nonsense,
2444 * so if you're trying to figure it out, start by ignoring that
2445 */
2446 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)2447 writer_write_reader_helper (DBusTypeWriter *writer,
2448 DBusTypeReader *reader,
2449 const DBusTypeReader *start_after,
2450 int start_after_new_pos,
2451 int start_after_new_len,
2452 DBusList **fixups,
2453 dbus_bool_t inside_start_after)
2454 {
2455 int current_type;
2456
2457 while ((current_type = _dbus_type_reader_get_current_type (reader)) != DBUS_TYPE_INVALID)
2458 {
2459 if (dbus_type_is_container (current_type))
2460 {
2461 DBusTypeReader subreader;
2462 DBusTypeWriter subwriter;
2463 const DBusString *sig_str;
2464 int sig_start;
2465 int sig_len;
2466 dbus_bool_t enabled_at_recurse;
2467 dbus_bool_t past_start_after;
2468 int reader_array_len_pos;
2469 int reader_array_start_pos;
2470 dbus_bool_t this_is_start_after;
2471
2472 /* type_pos is checked since e.g. in a struct the struct
2473 * and its first field have the same value_pos.
2474 * type_str will differ in reader/start_after for variants
2475 * where type_str is inside the value_str
2476 */
2477 if (!inside_start_after && start_after &&
2478 reader->value_pos == start_after->value_pos &&
2479 reader->type_str == start_after->type_str &&
2480 reader->type_pos == start_after->type_pos)
2481 this_is_start_after = TRUE;
2482 else
2483 this_is_start_after = FALSE;
2484
2485 _dbus_type_reader_recurse (reader, &subreader);
2486
2487 if (current_type == DBUS_TYPE_ARRAY)
2488 {
2489 reader_array_len_pos = ARRAY_READER_LEN_POS (&subreader);
2490 reader_array_start_pos = subreader.u.array.start_pos;
2491 }
2492 else
2493 {
2494 /* quiet gcc */
2495 reader_array_len_pos = -1;
2496 reader_array_start_pos = -1;
2497 }
2498
2499 _dbus_type_reader_get_signature (&subreader, &sig_str,
2500 &sig_start, &sig_len);
2501
2502 #if RECURSIVE_MARSHAL_WRITE_TRACE
2503 _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",
2504 _dbus_type_to_string (current_type),
2505 reader->value_pos,
2506 subreader.value_pos,
2507 writer->value_pos,
2508 start_after ? start_after->value_pos : -1,
2509 _dbus_string_get_length (writer->value_str),
2510 inside_start_after, this_is_start_after);
2511 #endif
2512
2513 if (!inside_start_after && !this_is_start_after)
2514 enable_if_after (writer, &subreader, start_after);
2515 enabled_at_recurse = writer->enabled;
2516 if (!_dbus_type_writer_recurse_contained_len (writer, current_type,
2517 sig_str, sig_start, sig_len,
2518 &subwriter, FALSE))
2519 goto oom;
2520
2521 #if RECURSIVE_MARSHAL_WRITE_TRACE
2522 _dbus_verbose ("recursed into subwriter at %d write target len %d\n",
2523 subwriter.value_pos,
2524 _dbus_string_get_length (subwriter.value_str));
2525 #endif
2526
2527 if (!writer_write_reader_helper (&subwriter, &subreader, start_after,
2528 start_after_new_pos, start_after_new_len,
2529 fixups,
2530 inside_start_after ||
2531 this_is_start_after))
2532 goto oom;
2533
2534 #if RECURSIVE_MARSHAL_WRITE_TRACE
2535 _dbus_verbose ("about to unrecurse from %s subreader at %d writer at %d subwriter at %d write target len %d\n",
2536 _dbus_type_to_string (current_type),
2537 subreader.value_pos,
2538 writer->value_pos,
2539 subwriter.value_pos,
2540 _dbus_string_get_length (writer->value_str));
2541 #endif
2542
2543 if (!inside_start_after && !this_is_start_after)
2544 enable_if_after (writer, &subreader, start_after);
2545 past_start_after = writer->enabled;
2546 if (!_dbus_type_writer_unrecurse (writer, &subwriter))
2547 goto oom;
2548
2549 /* If we weren't enabled when we recursed, we didn't
2550 * write an array len; if we passed start_after
2551 * somewhere inside the array, then we need to generate
2552 * a fixup.
2553 */
2554 if (start_after != NULL &&
2555 !enabled_at_recurse && past_start_after &&
2556 current_type == DBUS_TYPE_ARRAY &&
2557 fixups != NULL)
2558 {
2559 DBusArrayLenFixup fixup;
2560 int bytes_written_after_start_after;
2561 int bytes_before_start_after;
2562 int old_len;
2563
2564 /* this subwriter access is moderately unkosher since we
2565 * already unrecursed, but it works as long as unrecurse
2566 * doesn't break us on purpose
2567 */
2568 bytes_written_after_start_after = writer_get_array_len (&subwriter);
2569
2570 bytes_before_start_after =
2571 start_after->value_pos - reader_array_start_pos;
2572
2573 fixup.len_pos_in_reader = reader_array_len_pos;
2574 fixup.new_len =
2575 bytes_before_start_after +
2576 start_after_new_len +
2577 bytes_written_after_start_after;
2578
2579 _dbus_assert (_DBUS_ALIGN_VALUE (fixup.len_pos_in_reader, 4) ==
2580 (unsigned) fixup.len_pos_in_reader);
2581
2582 old_len = _dbus_unpack_uint32 (reader->byte_order,
2583 _dbus_string_get_const_udata_len (reader->value_str,
2584 fixup.len_pos_in_reader, 4));
2585
2586 if (old_len != fixup.new_len && !append_fixup (fixups, &fixup))
2587 goto oom;
2588
2589 #if RECURSIVE_MARSHAL_WRITE_TRACE
2590 _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",
2591 fixup.len_pos_in_reader,
2592 fixup.new_len,
2593 reader_array_start_pos,
2594 start_after->value_pos,
2595 bytes_before_start_after,
2596 start_after_new_len,
2597 bytes_written_after_start_after);
2598 #endif
2599 }
2600 }
2601 else
2602 {
2603 DBusBasicValue val;
2604
2605 _dbus_assert (dbus_type_is_basic (current_type));
2606
2607 #if RECURSIVE_MARSHAL_WRITE_TRACE
2608 _dbus_verbose ("Reading basic value %s at %d\n",
2609 _dbus_type_to_string (current_type),
2610 reader->value_pos);
2611 #endif
2612
2613 _dbus_type_reader_read_basic (reader, &val);
2614
2615 #if RECURSIVE_MARSHAL_WRITE_TRACE
2616 _dbus_verbose ("Writing basic value %s at %d write target len %d inside_start_after = %d\n",
2617 _dbus_type_to_string (current_type),
2618 writer->value_pos,
2619 _dbus_string_get_length (writer->value_str),
2620 inside_start_after);
2621 #endif
2622 if (!inside_start_after)
2623 enable_if_after (writer, reader, start_after);
2624 if (!_dbus_type_writer_write_basic (writer, current_type, &val))
2625 goto oom;
2626 #if RECURSIVE_MARSHAL_WRITE_TRACE
2627 _dbus_verbose ("Wrote basic value %s, new value_pos %d write target len %d\n",
2628 _dbus_type_to_string (current_type),
2629 writer->value_pos,
2630 _dbus_string_get_length (writer->value_str));
2631 #endif
2632 }
2633
2634 _dbus_type_reader_next (reader);
2635 }
2636
2637 return TRUE;
2638
2639 oom:
2640 if (fixups)
2641 apply_and_free_fixups (fixups, NULL); /* NULL for reader to apply to */
2642
2643 return FALSE;
2644 }
2645
2646 /*
2647 * Iterate through all values in the given reader, writing a copy of
2648 * each value to the writer. The reader will be moved forward to its
2649 * end position.
2650 *
2651 * If a reader start_after is provided, it should be a reader for the
2652 * same data as the reader to be written. Only values occurring after
2653 * the value pointed to by start_after will be written to the writer.
2654 *
2655 * If start_after is provided, then the copy of the reader will be
2656 * partial. This means that array lengths will not have been copied.
2657 * The assumption is that you wrote a new version of the value at
2658 * start_after to the writer. You have to pass in the start position
2659 * and length of the new value. (If you are deleting the value
2660 * at start_after, pass in 0 for the length.)
2661 *
2662 * If the fixups parameter is non-#NULL, then any array length that
2663 * was read but not written due to start_after will be provided
2664 * as a #DBusArrayLenFixup. The fixup contains the position of the
2665 * array length in the source data, and the correct array length
2666 * assuming you combine the source data before start_after with
2667 * the written data at start_after and beyond.
2668 *
2669 * @param writer the writer to copy to
2670 * @param reader the reader to copy from
2671 * @param start_after #NULL or a reader showing where to start
2672 * @param start_after_new_pos the position of start_after equivalent in the target data
2673 * @param start_after_new_len the length of start_after equivalent in the target data
2674 * @param fixups list to append #DBusArrayLenFixup if the write was partial
2675 * @returns #FALSE if no memory
2676 */
2677 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)2678 _dbus_type_writer_write_reader_partial (DBusTypeWriter *writer,
2679 DBusTypeReader *reader,
2680 const DBusTypeReader *start_after,
2681 int start_after_new_pos,
2682 int start_after_new_len,
2683 DBusList **fixups)
2684 {
2685 DBusTypeWriter orig;
2686 int orig_type_len;
2687 int orig_value_len;
2688 int new_bytes;
2689 int orig_enabled;
2690
2691 orig = *writer;
2692 orig_type_len = _dbus_string_get_length (writer->type_str);
2693 orig_value_len = _dbus_string_get_length (writer->value_str);
2694 orig_enabled = writer->enabled;
2695
2696 if (start_after)
2697 _dbus_type_writer_set_enabled (writer, FALSE);
2698
2699 if (!writer_write_reader_helper (writer, reader, start_after,
2700 start_after_new_pos,
2701 start_after_new_len,
2702 fixups, FALSE))
2703 goto oom;
2704
2705 _dbus_type_writer_set_enabled (writer, orig_enabled);
2706 return TRUE;
2707
2708 oom:
2709 if (!writer->type_pos_is_expectation)
2710 {
2711 new_bytes = _dbus_string_get_length (writer->type_str) - orig_type_len;
2712 _dbus_string_delete (writer->type_str, orig.type_pos, new_bytes);
2713 }
2714 new_bytes = _dbus_string_get_length (writer->value_str) - orig_value_len;
2715 _dbus_string_delete (writer->value_str, orig.value_pos, new_bytes);
2716
2717 *writer = orig;
2718
2719 return FALSE;
2720 }
2721
2722 /**
2723 * Iterate through all values in the given reader, writing a copy of
2724 * each value to the writer. The reader will be moved forward to its
2725 * end position.
2726 *
2727 * @param writer the writer to copy to
2728 * @param reader the reader to copy from
2729 * @returns #FALSE if no memory
2730 */
2731 dbus_bool_t
_dbus_type_writer_write_reader(DBusTypeWriter * writer,DBusTypeReader * reader)2732 _dbus_type_writer_write_reader (DBusTypeWriter *writer,
2733 DBusTypeReader *reader)
2734 {
2735 return _dbus_type_writer_write_reader_partial (writer, reader, NULL, 0, 0, NULL);
2736 }
2737
2738 /*
2739 * If disabled, a writer can still be iterated forward and recursed/unrecursed
2740 * but won't write any values. Types will still be written unless the
2741 * writer is a "values only" writer, because the writer needs access to
2742 * a valid signature to be able to iterate.
2743 *
2744 * @param writer the type writer
2745 * @param enabled #TRUE if values should be written
2746 */
2747 static void
_dbus_type_writer_set_enabled(DBusTypeWriter * writer,dbus_bool_t enabled)2748 _dbus_type_writer_set_enabled (DBusTypeWriter *writer,
2749 dbus_bool_t enabled)
2750 {
2751 writer->enabled = enabled != FALSE;
2752 }
2753
2754 /** @} */ /* end of DBusMarshal group */
2755
2756 /* tests in dbus-marshal-recursive-util.c */
2757