1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-string.c String utility class (internal to D-Bus implementation)
3 *
4 * Copyright (C) 2002, 2003, 2004, 2005 Red Hat, Inc.
5 * Copyright (C) 2006 Ralf Habacker <ralf.habacker@freenet.de>
6 *
7 * Licensed under the Academic Free License version 2.1
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 */
24
25 #include <config.h>
26 #include "dbus-internals.h"
27 #include "dbus-string.h"
28 /* we allow a system header here, for speed/convenience */
29 #include <string.h>
30 /* for vsnprintf */
31 #include <stdio.h>
32 #define DBUS_CAN_USE_DBUS_STRING_PRIVATE 1
33 #include "dbus-string-private.h"
34 #include "dbus-marshal-basic.h" /* probably should be removed by moving the usage of DBUS_TYPE
35 * into the marshaling-related files
36 */
37 /* for DBUS_VA_COPY */
38 #include "dbus-sysdeps.h"
39
40 /**
41 * @defgroup DBusString DBusString class
42 * @ingroup DBusInternals
43 * @brief DBusString data structure for safer string handling
44 *
45 * Types and functions related to DBusString. DBusString is intended
46 * to be a string class that makes it hard to mess up security issues
47 * (and just in general harder to write buggy code). It should be
48 * used (or extended and then used) rather than the libc stuff in
49 * string.h. The string class is a bit inconvenient at spots because
50 * it handles out-of-memory failures and tries to be extra-robust.
51 *
52 * A DBusString has a maximum length set at initialization time; this
53 * can be used to ensure that a buffer doesn't get too big. The
54 * _dbus_string_lengthen() method checks for overflow, and for max
55 * length being exceeded.
56 *
57 * Try to avoid conversion to a plain C string, i.e. add methods on
58 * the string object instead, only convert to C string when passing
59 * things out to the public API. In particular, no sprintf, strcpy,
60 * strcat, any of that should be used. The GString feature of
61 * accepting negative numbers for "length of string" is also absent,
62 * because it could keep us from detecting bogus huge lengths. i.e. if
63 * we passed in some bogus huge length it would be taken to mean
64 * "current length of string" instead of "broken crack"
65 *
66 * @todo #DBusString needs a lot of cleaning up; some of the
67 * API is no longer used, and the API is pretty inconsistent.
68 * In particular all the "append" APIs, especially those involving
69 * alignment but probably lots of them, are no longer used by the
70 * marshaling code which always does "inserts" now.
71 */
72
73 /**
74 * @addtogroup DBusString
75 * @{
76 */
77
78 static void
fixup_alignment(DBusRealString * real)79 fixup_alignment (DBusRealString *real)
80 {
81 unsigned char *aligned;
82 unsigned char *real_block;
83 unsigned int old_align_offset;
84
85 /* we have to have extra space in real->allocated for the align offset and nul byte */
86 _dbus_assert (real->len <= real->allocated - _DBUS_STRING_ALLOCATION_PADDING);
87
88 old_align_offset = real->align_offset;
89 real_block = real->str - old_align_offset;
90
91 aligned = _DBUS_ALIGN_ADDRESS (real_block, 8);
92
93 real->align_offset = aligned - real_block;
94 real->str = aligned;
95
96 if (old_align_offset != real->align_offset)
97 {
98 /* Here comes the suck */
99 memmove (real_block + real->align_offset,
100 real_block + old_align_offset,
101 real->len + 1);
102 }
103
104 _dbus_assert (real->align_offset < 8);
105 _dbus_assert (_DBUS_ALIGN_ADDRESS (real->str, 8) == real->str);
106 }
107
108 static void
undo_alignment(DBusRealString * real)109 undo_alignment (DBusRealString *real)
110 {
111 if (real->align_offset != 0)
112 {
113 memmove (real->str - real->align_offset,
114 real->str,
115 real->len + 1);
116
117 real->str = real->str - real->align_offset;
118 real->align_offset = 0;
119 }
120 }
121
122 /**
123 * Initializes a string that can be up to the given allocation size
124 * before it has to realloc. The string starts life with zero length.
125 * The string must eventually be freed with _dbus_string_free().
126 *
127 * @param str memory to hold the string
128 * @param allocate_size amount to preallocate
129 * @returns #TRUE on success, #FALSE if no memory
130 */
131 dbus_bool_t
_dbus_string_init_preallocated(DBusString * str,int allocate_size)132 _dbus_string_init_preallocated (DBusString *str,
133 int allocate_size)
134 {
135 DBusRealString *real;
136
137 _dbus_assert (str != NULL);
138
139 _dbus_assert (sizeof (DBusString) == sizeof (DBusRealString));
140
141 real = (DBusRealString*) str;
142
143 /* It's very important not to touch anything
144 * other than real->str if we're going to fail,
145 * since we also use this function to reset
146 * an existing string, e.g. in _dbus_string_steal_data()
147 */
148
149 real->str = dbus_malloc (_DBUS_STRING_ALLOCATION_PADDING + allocate_size);
150 if (real->str == NULL)
151 return FALSE;
152
153 real->allocated = _DBUS_STRING_ALLOCATION_PADDING + allocate_size;
154 real->len = 0;
155 real->str[real->len] = '\0';
156
157 real->constant = FALSE;
158 real->locked = FALSE;
159 real->invalid = FALSE;
160 real->align_offset = 0;
161
162 fixup_alignment (real);
163
164 return TRUE;
165 }
166
167 /**
168 * Initializes a string. The string starts life with zero length. The
169 * string must eventually be freed with _dbus_string_free().
170 *
171 * @param str memory to hold the string
172 * @returns #TRUE on success, #FALSE if no memory
173 */
174 dbus_bool_t
_dbus_string_init(DBusString * str)175 _dbus_string_init (DBusString *str)
176 {
177 return _dbus_string_init_preallocated (str, 0);
178 }
179
180 /**
181 * Initializes a constant string. The value parameter is not copied
182 * (should be static), and the string may never be modified.
183 * It is safe but not necessary to call _dbus_string_free()
184 * on a const string. The string has a length limit of MAXINT - 8.
185 *
186 * @param str memory to use for the string
187 * @param value a string to be stored in str (not copied!!!)
188 */
189 void
_dbus_string_init_const(DBusString * str,const char * value)190 _dbus_string_init_const (DBusString *str,
191 const char *value)
192 {
193 _dbus_assert (value != NULL);
194
195 _dbus_string_init_const_len (str, value,
196 strlen (value));
197 }
198
199 /**
200 * Initializes a constant string with a length. The value parameter is
201 * not copied (should be static), and the string may never be
202 * modified. It is safe but not necessary to call _dbus_string_free()
203 * on a const string.
204 *
205 * @param str memory to use for the string
206 * @param value a string to be stored in str (not copied!!!)
207 * @param len the length to use
208 */
209 void
_dbus_string_init_const_len(DBusString * str,const char * value,int len)210 _dbus_string_init_const_len (DBusString *str,
211 const char *value,
212 int len)
213 {
214 DBusRealString *real;
215
216 _dbus_assert (str != NULL);
217 _dbus_assert (len == 0 || value != NULL);
218 _dbus_assert (len <= _DBUS_STRING_MAX_LENGTH);
219 _dbus_assert (len >= 0);
220
221 real = (DBusRealString*) str;
222
223 real->str = (unsigned char*) value;
224 real->len = len;
225 real->allocated = real->len + _DBUS_STRING_ALLOCATION_PADDING; /* a lie, just to avoid special-case assertions... */
226 real->constant = TRUE;
227 real->locked = TRUE;
228 real->invalid = FALSE;
229 real->align_offset = 0;
230
231 /* We don't require const strings to be 8-byte aligned as the
232 * memory is coming from elsewhere.
233 */
234 }
235
236 /**
237 * Frees a string created by _dbus_string_init().
238 *
239 * @param str memory where the string is stored.
240 */
241 void
_dbus_string_free(DBusString * str)242 _dbus_string_free (DBusString *str)
243 {
244 DBusRealString *real = (DBusRealString*) str;
245 DBUS_GENERIC_STRING_PREAMBLE (real);
246
247 if (real->constant)
248 return;
249 dbus_free (real->str - real->align_offset);
250
251 real->invalid = TRUE;
252 }
253
254 static dbus_bool_t
compact(DBusRealString * real,int max_waste)255 compact (DBusRealString *real,
256 int max_waste)
257 {
258 unsigned char *new_str;
259 int new_allocated;
260 int waste;
261
262 waste = real->allocated - (real->len + _DBUS_STRING_ALLOCATION_PADDING);
263
264 if (waste <= max_waste)
265 return TRUE;
266
267 new_allocated = real->len + _DBUS_STRING_ALLOCATION_PADDING;
268
269 new_str = dbus_realloc (real->str - real->align_offset, new_allocated);
270 if (_DBUS_UNLIKELY (new_str == NULL))
271 return FALSE;
272
273 real->str = new_str + real->align_offset;
274 real->allocated = new_allocated;
275 fixup_alignment (real);
276
277 return TRUE;
278 }
279
280 #ifdef DBUS_BUILD_TESTS
281 /* Not using this feature at the moment,
282 * so marked DBUS_BUILD_TESTS-only
283 */
284 /**
285 * Locks a string such that any attempts to change the string will
286 * result in aborting the program. Also, if the string is wasting a
287 * lot of memory (allocation is sufficiently larger than what the
288 * string is really using), _dbus_string_lock() will realloc the
289 * string's data to "compact" it.
290 *
291 * @param str the string to lock.
292 */
293 void
_dbus_string_lock(DBusString * str)294 _dbus_string_lock (DBusString *str)
295 {
296 DBUS_LOCKED_STRING_PREAMBLE (str); /* can lock multiple times */
297
298 real->locked = TRUE;
299
300 /* Try to realloc to avoid excess memory usage, since
301 * we know we won't change the string further
302 */
303 #define MAX_WASTE 48
304 compact (real, MAX_WASTE);
305 }
306 #endif /* DBUS_BUILD_TESTS */
307
308 static dbus_bool_t
reallocate_for_length(DBusRealString * real,int new_length)309 reallocate_for_length (DBusRealString *real,
310 int new_length)
311 {
312 int new_allocated;
313 unsigned char *new_str;
314
315 /* at least double our old allocation to avoid O(n), avoiding
316 * overflow
317 */
318 if (real->allocated > (_DBUS_STRING_MAX_LENGTH + _DBUS_STRING_ALLOCATION_PADDING) / 2)
319 new_allocated = _DBUS_STRING_MAX_LENGTH + _DBUS_STRING_ALLOCATION_PADDING;
320 else
321 new_allocated = real->allocated * 2;
322
323 /* if you change the code just above here, run the tests without
324 * the following assert-only hack before you commit
325 */
326 /* This is keyed off asserts in addition to tests so when you
327 * disable asserts to profile, you don't get this destroyer
328 * of profiles.
329 */
330 #ifdef DBUS_DISABLE_ASSERT
331 #else
332 #ifdef DBUS_BUILD_TESTS
333 new_allocated = 0; /* ensure a realloc every time so that we go
334 * through all malloc failure codepaths
335 */
336 #endif /* DBUS_BUILD_TESTS */
337 #endif /* !DBUS_DISABLE_ASSERT */
338
339 /* But be sure we always alloc at least space for the new length */
340 new_allocated = MAX (new_allocated,
341 new_length + _DBUS_STRING_ALLOCATION_PADDING);
342
343 _dbus_assert (new_allocated >= real->allocated); /* code relies on this */
344 new_str = dbus_realloc (real->str - real->align_offset, new_allocated);
345 if (_DBUS_UNLIKELY (new_str == NULL))
346 return FALSE;
347
348 real->str = new_str + real->align_offset;
349 real->allocated = new_allocated;
350 fixup_alignment (real);
351
352 return TRUE;
353 }
354
355 /**
356 * Compacts the string to avoid wasted memory. Wasted memory is
357 * memory that is allocated but not actually required to store the
358 * current length of the string. The compact is only done if more
359 * than the given amount of memory is being wasted (otherwise the
360 * waste is ignored and the call does nothing).
361 *
362 * @param str the string
363 * @param max_waste the maximum amount of waste to ignore
364 * @returns #FALSE if the compact failed due to realloc failure
365 */
366 dbus_bool_t
_dbus_string_compact(DBusString * str,int max_waste)367 _dbus_string_compact (DBusString *str,
368 int max_waste)
369 {
370 DBUS_STRING_PREAMBLE (str);
371
372 return compact (real, max_waste);
373 }
374
375 static dbus_bool_t
set_length(DBusRealString * real,int new_length)376 set_length (DBusRealString *real,
377 int new_length)
378 {
379 /* Note, we are setting the length not including nul termination */
380
381 /* exceeding max length is the same as failure to allocate memory */
382 if (_DBUS_UNLIKELY (new_length > _DBUS_STRING_MAX_LENGTH))
383 return FALSE;
384 else if (new_length > (real->allocated - _DBUS_STRING_ALLOCATION_PADDING) &&
385 _DBUS_UNLIKELY (!reallocate_for_length (real, new_length)))
386 return FALSE;
387 else
388 {
389 real->len = new_length;
390 real->str[new_length] = '\0';
391 return TRUE;
392 }
393 }
394
395 static dbus_bool_t
open_gap(int len,DBusRealString * dest,int insert_at)396 open_gap (int len,
397 DBusRealString *dest,
398 int insert_at)
399 {
400 if (len == 0)
401 return TRUE;
402
403 if (len > _DBUS_STRING_MAX_LENGTH - dest->len)
404 return FALSE; /* detected overflow of dest->len + len below */
405
406 if (!set_length (dest, dest->len + len))
407 return FALSE;
408
409 memmove (dest->str + insert_at + len,
410 dest->str + insert_at,
411 dest->len - len - insert_at);
412
413 return TRUE;
414 }
415
416 #ifndef _dbus_string_get_data
417 /**
418 * Gets the raw character buffer from the string. The returned buffer
419 * will be nul-terminated, but note that strings may contain binary
420 * data so there may be extra nul characters prior to the termination.
421 * This function should be little-used, extend DBusString or add
422 * stuff to dbus-sysdeps.c instead. It's an error to use this
423 * function on a const string.
424 *
425 * @param str the string
426 * @returns the data
427 */
428 char*
_dbus_string_get_data(DBusString * str)429 _dbus_string_get_data (DBusString *str)
430 {
431 DBUS_STRING_PREAMBLE (str);
432
433 return (char*) real->str;
434 }
435 #endif /* _dbus_string_get_data */
436
437 /* only do the function if we don't have the macro */
438 #ifndef _dbus_string_get_const_data
439 /**
440 * Gets the raw character buffer from a const string.
441 *
442 * @param str the string
443 * @returns the string data
444 */
445 const char*
_dbus_string_get_const_data(const DBusString * str)446 _dbus_string_get_const_data (const DBusString *str)
447 {
448 DBUS_CONST_STRING_PREAMBLE (str);
449
450 return (const char*) real->str;
451 }
452 #endif /* _dbus_string_get_const_data */
453
454 /**
455 * Gets a sub-portion of the raw character buffer from the
456 * string. The "len" field is required simply for error
457 * checking, to be sure you don't try to use more
458 * string than exists. The nul termination of the
459 * returned buffer remains at the end of the entire
460 * string, not at start + len.
461 *
462 * @param str the string
463 * @param start byte offset to return
464 * @param len length of segment to return
465 * @returns the string data
466 */
467 char*
_dbus_string_get_data_len(DBusString * str,int start,int len)468 _dbus_string_get_data_len (DBusString *str,
469 int start,
470 int len)
471 {
472 DBUS_STRING_PREAMBLE (str);
473 _dbus_assert (start >= 0);
474 _dbus_assert (len >= 0);
475 _dbus_assert (start <= real->len);
476 _dbus_assert (len <= real->len - start);
477
478 return (char*) real->str + start;
479 }
480
481 /* only do the function if we don't have the macro */
482 #ifndef _dbus_string_get_const_data_len
483 /**
484 * const version of _dbus_string_get_data_len().
485 *
486 * @param str the string
487 * @param start byte offset to return
488 * @param len length of segment to return
489 * @returns the string data
490 */
491 const char*
_dbus_string_get_const_data_len(const DBusString * str,int start,int len)492 _dbus_string_get_const_data_len (const DBusString *str,
493 int start,
494 int len)
495 {
496 DBUS_CONST_STRING_PREAMBLE (str);
497 _dbus_assert (start >= 0);
498 _dbus_assert (len >= 0);
499 _dbus_assert (start <= real->len);
500 _dbus_assert (len <= real->len - start);
501
502 return (const char*) real->str + start;
503 }
504 #endif /* _dbus_string_get_const_data_len */
505
506 /* only do the function if we don't have the macro */
507 #ifndef _dbus_string_set_byte
508 /**
509 * Sets the value of the byte at the given position.
510 *
511 * @param str the string
512 * @param i the position
513 * @param byte the new value
514 */
515 void
_dbus_string_set_byte(DBusString * str,int i,unsigned char byte)516 _dbus_string_set_byte (DBusString *str,
517 int i,
518 unsigned char byte)
519 {
520 DBUS_STRING_PREAMBLE (str);
521 _dbus_assert (i < real->len);
522 _dbus_assert (i >= 0);
523
524 real->str[i] = byte;
525 }
526 #endif /* _dbus_string_set_byte */
527
528 /* only have the function if we didn't create a macro */
529 #ifndef _dbus_string_get_byte
530 /**
531 * Gets the byte at the given position. It is
532 * allowed to ask for the nul byte at the end of
533 * the string.
534 *
535 * @param str the string
536 * @param start the position
537 * @returns the byte at that position
538 */
539 unsigned char
_dbus_string_get_byte(const DBusString * str,int start)540 _dbus_string_get_byte (const DBusString *str,
541 int start)
542 {
543 DBUS_CONST_STRING_PREAMBLE (str);
544 _dbus_assert (start <= real->len);
545 _dbus_assert (start >= 0);
546
547 return real->str[start];
548 }
549 #endif /* _dbus_string_get_byte */
550
551 /**
552 * Inserts a number of bytes of a given value at the
553 * given position.
554 *
555 * @param str the string
556 * @param i the position
557 * @param n_bytes number of bytes
558 * @param byte the value to insert
559 * @returns #TRUE on success
560 */
561 dbus_bool_t
_dbus_string_insert_bytes(DBusString * str,int i,int n_bytes,unsigned char byte)562 _dbus_string_insert_bytes (DBusString *str,
563 int i,
564 int n_bytes,
565 unsigned char byte)
566 {
567 DBUS_STRING_PREAMBLE (str);
568 _dbus_assert (i <= real->len);
569 _dbus_assert (i >= 0);
570 _dbus_assert (n_bytes >= 0);
571
572 if (n_bytes == 0)
573 return TRUE;
574
575 if (!open_gap (n_bytes, real, i))
576 return FALSE;
577
578 memset (real->str + i, byte, n_bytes);
579
580 return TRUE;
581 }
582
583 /**
584 * Inserts a single byte at the given position.
585 *
586 * @param str the string
587 * @param i the position
588 * @param byte the value to insert
589 * @returns #TRUE on success
590 */
591 dbus_bool_t
_dbus_string_insert_byte(DBusString * str,int i,unsigned char byte)592 _dbus_string_insert_byte (DBusString *str,
593 int i,
594 unsigned char byte)
595 {
596 DBUS_STRING_PREAMBLE (str);
597 _dbus_assert (i <= real->len);
598 _dbus_assert (i >= 0);
599
600 if (!open_gap (1, real, i))
601 return FALSE;
602
603 real->str[i] = byte;
604
605 return TRUE;
606 }
607
608 /**
609 * Like _dbus_string_get_data(), but removes the
610 * gotten data from the original string. The caller
611 * must free the data returned. This function may
612 * fail due to lack of memory, and return #FALSE.
613 *
614 * @param str the string
615 * @param data_return location to return the buffer
616 * @returns #TRUE on success
617 */
618 dbus_bool_t
_dbus_string_steal_data(DBusString * str,char ** data_return)619 _dbus_string_steal_data (DBusString *str,
620 char **data_return)
621 {
622 DBUS_STRING_PREAMBLE (str);
623 _dbus_assert (data_return != NULL);
624
625 undo_alignment (real);
626
627 *data_return = (char*) real->str;
628
629 /* reset the string */
630 if (!_dbus_string_init (str))
631 {
632 /* hrm, put it back then */
633 real->str = (unsigned char*) *data_return;
634 *data_return = NULL;
635 fixup_alignment (real);
636 return FALSE;
637 }
638
639 return TRUE;
640 }
641
642 /**
643 * Copies the data from the string into a char*
644 *
645 * @param str the string
646 * @param data_return place to return the data
647 * @returns #TRUE on success, #FALSE on no memory
648 */
649 dbus_bool_t
_dbus_string_copy_data(const DBusString * str,char ** data_return)650 _dbus_string_copy_data (const DBusString *str,
651 char **data_return)
652 {
653 DBUS_CONST_STRING_PREAMBLE (str);
654 _dbus_assert (data_return != NULL);
655
656 *data_return = dbus_malloc (real->len + 1);
657 if (*data_return == NULL)
658 return FALSE;
659
660 memcpy (*data_return, real->str, real->len + 1);
661
662 return TRUE;
663 }
664
665 /**
666 * Copies the contents of a DBusString into a different buffer. It is
667 * a bug if avail_len is too short to hold the string contents. nul
668 * termination is not copied, just the supplied bytes.
669 *
670 * @param str a string
671 * @param buffer a C buffer to copy data to
672 * @param avail_len maximum length of C buffer
673 */
674 void
_dbus_string_copy_to_buffer(const DBusString * str,char * buffer,int avail_len)675 _dbus_string_copy_to_buffer (const DBusString *str,
676 char *buffer,
677 int avail_len)
678 {
679 DBUS_CONST_STRING_PREAMBLE (str);
680
681 _dbus_assert (avail_len >= 0);
682 _dbus_assert (avail_len >= real->len);
683
684 memcpy (buffer, real->str, real->len);
685 }
686
687 /**
688 * Copies the contents of a DBusString into a different buffer. It is
689 * a bug if avail_len is too short to hold the string contents plus a
690 * nul byte.
691 *
692 * @param str a string
693 * @param buffer a C buffer to copy data to
694 * @param avail_len maximum length of C buffer
695 */
696 void
_dbus_string_copy_to_buffer_with_nul(const DBusString * str,char * buffer,int avail_len)697 _dbus_string_copy_to_buffer_with_nul (const DBusString *str,
698 char *buffer,
699 int avail_len)
700 {
701 DBUS_CONST_STRING_PREAMBLE (str);
702
703 _dbus_assert (avail_len >= 0);
704 _dbus_assert (avail_len > real->len);
705
706 memcpy (buffer, real->str, real->len+1);
707 }
708
709 /* Only have the function if we don't have the macro */
710 #ifndef _dbus_string_get_length
711 /**
712 * Gets the length of a string (not including nul termination).
713 *
714 * @returns the length.
715 */
716 int
_dbus_string_get_length(const DBusString * str)717 _dbus_string_get_length (const DBusString *str)
718 {
719 DBUS_CONST_STRING_PREAMBLE (str);
720
721 return real->len;
722 }
723 #endif /* !_dbus_string_get_length */
724
725 /**
726 * Makes a string longer by the given number of bytes. Checks whether
727 * adding additional_length to the current length would overflow an
728 * integer, and checks for exceeding a string's max length.
729 * The new bytes are not initialized, other than nul-terminating
730 * the end of the string. The uninitialized bytes may contain
731 * nul bytes or other junk.
732 *
733 * @param str a string
734 * @param additional_length length to add to the string.
735 * @returns #TRUE on success.
736 */
737 dbus_bool_t
_dbus_string_lengthen(DBusString * str,int additional_length)738 _dbus_string_lengthen (DBusString *str,
739 int additional_length)
740 {
741 DBUS_STRING_PREAMBLE (str);
742 _dbus_assert (additional_length >= 0);
743
744 if (_DBUS_UNLIKELY (additional_length > _DBUS_STRING_MAX_LENGTH - real->len))
745 return FALSE; /* would overflow */
746
747 return set_length (real,
748 real->len + additional_length);
749 }
750
751 /**
752 * Makes a string shorter by the given number of bytes.
753 *
754 * @param str a string
755 * @param length_to_remove length to remove from the string.
756 */
757 void
_dbus_string_shorten(DBusString * str,int length_to_remove)758 _dbus_string_shorten (DBusString *str,
759 int length_to_remove)
760 {
761 DBUS_STRING_PREAMBLE (str);
762 _dbus_assert (length_to_remove >= 0);
763 _dbus_assert (length_to_remove <= real->len);
764
765 set_length (real,
766 real->len - length_to_remove);
767 }
768
769 /**
770 * Sets the length of a string. Can be used to truncate or lengthen
771 * the string. If the string is lengthened, the function may fail and
772 * return #FALSE. Newly-added bytes are not initialized, as with
773 * _dbus_string_lengthen().
774 *
775 * @param str a string
776 * @param length new length of the string.
777 * @returns #FALSE on failure.
778 */
779 dbus_bool_t
_dbus_string_set_length(DBusString * str,int length)780 _dbus_string_set_length (DBusString *str,
781 int length)
782 {
783 DBUS_STRING_PREAMBLE (str);
784 _dbus_assert (length >= 0);
785
786 return set_length (real, length);
787 }
788
789 static dbus_bool_t
align_insert_point_then_open_gap(DBusString * str,int * insert_at_p,int alignment,int gap_size)790 align_insert_point_then_open_gap (DBusString *str,
791 int *insert_at_p,
792 int alignment,
793 int gap_size)
794 {
795 unsigned long new_len; /* ulong to avoid _DBUS_ALIGN_VALUE overflow */
796 unsigned long gap_pos;
797 int insert_at;
798 int delta;
799 DBUS_STRING_PREAMBLE (str);
800 _dbus_assert (alignment >= 1);
801 _dbus_assert (alignment <= 8); /* it has to be a bug if > 8 */
802
803 insert_at = *insert_at_p;
804
805 _dbus_assert (insert_at <= real->len);
806
807 gap_pos = _DBUS_ALIGN_VALUE (insert_at, alignment);
808 new_len = real->len + (gap_pos - insert_at) + gap_size;
809
810 if (_DBUS_UNLIKELY (new_len > (unsigned long) _DBUS_STRING_MAX_LENGTH))
811 return FALSE;
812
813 delta = new_len - real->len;
814 _dbus_assert (delta >= 0);
815
816 if (delta == 0) /* only happens if gap_size == 0 and insert_at is aligned already */
817 {
818 _dbus_assert (((unsigned long) *insert_at_p) == gap_pos);
819 return TRUE;
820 }
821
822 if (_DBUS_UNLIKELY (!open_gap (new_len - real->len,
823 real, insert_at)))
824 return FALSE;
825
826 /* nul the padding if we had to add any padding */
827 if (gap_size < delta)
828 {
829 memset (&real->str[insert_at], '\0',
830 gap_pos - insert_at);
831 }
832
833 *insert_at_p = gap_pos;
834
835 return TRUE;
836 }
837
838 static dbus_bool_t
align_length_then_lengthen(DBusString * str,int alignment,int then_lengthen_by)839 align_length_then_lengthen (DBusString *str,
840 int alignment,
841 int then_lengthen_by)
842 {
843 int insert_at;
844
845 insert_at = _dbus_string_get_length (str);
846
847 return align_insert_point_then_open_gap (str,
848 &insert_at,
849 alignment, then_lengthen_by);
850 }
851
852 /**
853 * Align the length of a string to a specific alignment (typically 4 or 8)
854 * by appending nul bytes to the string.
855 *
856 * @param str a string
857 * @param alignment the alignment
858 * @returns #FALSE if no memory
859 */
860 dbus_bool_t
_dbus_string_align_length(DBusString * str,int alignment)861 _dbus_string_align_length (DBusString *str,
862 int alignment)
863 {
864 return align_length_then_lengthen (str, alignment, 0);
865 }
866
867 /**
868 * Preallocate extra_bytes such that a future lengthening of the
869 * string by extra_bytes is guaranteed to succeed without an out of
870 * memory error.
871 *
872 * @param str a string
873 * @param extra_bytes bytes to alloc
874 * @returns #FALSE if no memory
875 */
876 dbus_bool_t
_dbus_string_alloc_space(DBusString * str,int extra_bytes)877 _dbus_string_alloc_space (DBusString *str,
878 int extra_bytes)
879 {
880 if (!_dbus_string_lengthen (str, extra_bytes))
881 return FALSE;
882 _dbus_string_shorten (str, extra_bytes);
883
884 return TRUE;
885 }
886
887 static dbus_bool_t
append(DBusRealString * real,const char * buffer,int buffer_len)888 append (DBusRealString *real,
889 const char *buffer,
890 int buffer_len)
891 {
892 if (buffer_len == 0)
893 return TRUE;
894
895 if (!_dbus_string_lengthen ((DBusString*)real, buffer_len))
896 return FALSE;
897
898 memcpy (real->str + (real->len - buffer_len),
899 buffer,
900 buffer_len);
901
902 return TRUE;
903 }
904
905 /**
906 * Appends a nul-terminated C-style string to a DBusString.
907 *
908 * @param str the DBusString
909 * @param buffer the nul-terminated characters to append
910 * @returns #FALSE if not enough memory.
911 */
912 dbus_bool_t
_dbus_string_append(DBusString * str,const char * buffer)913 _dbus_string_append (DBusString *str,
914 const char *buffer)
915 {
916 unsigned long buffer_len;
917
918 DBUS_STRING_PREAMBLE (str);
919 _dbus_assert (buffer != NULL);
920
921 buffer_len = strlen (buffer);
922 if (buffer_len > (unsigned long) _DBUS_STRING_MAX_LENGTH)
923 return FALSE;
924
925 return append (real, buffer, buffer_len);
926 }
927
928 /** assign 2 bytes from one string to another */
929 #define ASSIGN_2_OCTETS(p, octets) \
930 *((dbus_uint16_t*)(p)) = *((dbus_uint16_t*)(octets));
931
932 /** assign 4 bytes from one string to another */
933 #define ASSIGN_4_OCTETS(p, octets) \
934 *((dbus_uint32_t*)(p)) = *((dbus_uint32_t*)(octets));
935
936 #ifdef DBUS_HAVE_INT64
937 /** assign 8 bytes from one string to another */
938 #define ASSIGN_8_OCTETS(p, octets) \
939 *((dbus_uint64_t*)(p)) = *((dbus_uint64_t*)(octets));
940 #else
941 /** assign 8 bytes from one string to another */
942 #define ASSIGN_8_OCTETS(p, octets) \
943 do { \
944 unsigned char *b; \
945 \
946 b = p; \
947 \
948 *b++ = octets[0]; \
949 *b++ = octets[1]; \
950 *b++ = octets[2]; \
951 *b++ = octets[3]; \
952 *b++ = octets[4]; \
953 *b++ = octets[5]; \
954 *b++ = octets[6]; \
955 *b++ = octets[7]; \
956 _dbus_assert (b == p + 8); \
957 } while (0)
958 #endif /* DBUS_HAVE_INT64 */
959
960 /**
961 * Inserts 2 bytes aligned on a 2 byte boundary
962 * with any alignment padding initialized to 0.
963 *
964 * @param str the DBusString
965 * @param insert_at where to insert
966 * @param octets 2 bytes to insert
967 * @returns #FALSE if not enough memory.
968 */
969 dbus_bool_t
_dbus_string_insert_2_aligned(DBusString * str,int insert_at,const unsigned char octets[4])970 _dbus_string_insert_2_aligned (DBusString *str,
971 int insert_at,
972 const unsigned char octets[4])
973 {
974 DBUS_STRING_PREAMBLE (str);
975
976 if (!align_insert_point_then_open_gap (str, &insert_at, 2, 2))
977 return FALSE;
978
979 ASSIGN_2_OCTETS (real->str + insert_at, octets);
980
981 return TRUE;
982 }
983
984 /**
985 * Inserts 4 bytes aligned on a 4 byte boundary
986 * with any alignment padding initialized to 0.
987 *
988 * @param str the DBusString
989 * @param insert_at where to insert
990 * @param octets 4 bytes to insert
991 * @returns #FALSE if not enough memory.
992 */
993 dbus_bool_t
_dbus_string_insert_4_aligned(DBusString * str,int insert_at,const unsigned char octets[4])994 _dbus_string_insert_4_aligned (DBusString *str,
995 int insert_at,
996 const unsigned char octets[4])
997 {
998 DBUS_STRING_PREAMBLE (str);
999
1000 if (!align_insert_point_then_open_gap (str, &insert_at, 4, 4))
1001 return FALSE;
1002
1003 ASSIGN_4_OCTETS (real->str + insert_at, octets);
1004
1005 return TRUE;
1006 }
1007
1008 /**
1009 * Inserts 8 bytes aligned on an 8 byte boundary
1010 * with any alignment padding initialized to 0.
1011 *
1012 * @param str the DBusString
1013 * @param insert_at where to insert
1014 * @param octets 8 bytes to insert
1015 * @returns #FALSE if not enough memory.
1016 */
1017 dbus_bool_t
_dbus_string_insert_8_aligned(DBusString * str,int insert_at,const unsigned char octets[8])1018 _dbus_string_insert_8_aligned (DBusString *str,
1019 int insert_at,
1020 const unsigned char octets[8])
1021 {
1022 DBUS_STRING_PREAMBLE (str);
1023
1024 if (!align_insert_point_then_open_gap (str, &insert_at, 8, 8))
1025 return FALSE;
1026
1027 _dbus_assert (_DBUS_ALIGN_VALUE (insert_at, 8) == (unsigned) insert_at);
1028
1029 ASSIGN_8_OCTETS (real->str + insert_at, octets);
1030
1031 return TRUE;
1032 }
1033
1034
1035 /**
1036 * Inserts padding at *insert_at such to align it to the given
1037 * boundary. Initializes the padding to nul bytes. Sets *insert_at
1038 * to the aligned position.
1039 *
1040 * @param str the DBusString
1041 * @param insert_at location to be aligned
1042 * @param alignment alignment boundary (1, 2, 4, or 8)
1043 * @returns #FALSE if not enough memory.
1044 */
1045 dbus_bool_t
_dbus_string_insert_alignment(DBusString * str,int * insert_at,int alignment)1046 _dbus_string_insert_alignment (DBusString *str,
1047 int *insert_at,
1048 int alignment)
1049 {
1050 DBUS_STRING_PREAMBLE (str);
1051
1052 if (!align_insert_point_then_open_gap (str, insert_at, alignment, 0))
1053 return FALSE;
1054
1055 _dbus_assert (_DBUS_ALIGN_VALUE (*insert_at, alignment) == (unsigned) *insert_at);
1056
1057 return TRUE;
1058 }
1059
1060 /**
1061 * Appends a printf-style formatted string
1062 * to the #DBusString.
1063 *
1064 * @param str the string
1065 * @param format printf format
1066 * @param args variable argument list
1067 * @returns #FALSE if no memory
1068 */
1069 dbus_bool_t
_dbus_string_append_printf_valist(DBusString * str,const char * format,va_list args)1070 _dbus_string_append_printf_valist (DBusString *str,
1071 const char *format,
1072 va_list args)
1073 {
1074 int len;
1075 va_list args_copy;
1076
1077 DBUS_STRING_PREAMBLE (str);
1078
1079 DBUS_VA_COPY (args_copy, args);
1080
1081 /* Measure the message length without terminating nul */
1082 len = _dbus_printf_string_upper_bound (format, args);
1083
1084 if (len < 0)
1085 return FALSE;
1086
1087 if (!_dbus_string_lengthen (str, len))
1088 {
1089 /* don't leak the copy */
1090 va_end (args_copy);
1091 return FALSE;
1092 }
1093
1094 vsprintf ((char*) (real->str + (real->len - len)),
1095 format, args_copy);
1096
1097 va_end (args_copy);
1098
1099 return TRUE;
1100 }
1101
1102 /**
1103 * Appends a printf-style formatted string
1104 * to the #DBusString.
1105 *
1106 * @param str the string
1107 * @param format printf format
1108 * @returns #FALSE if no memory
1109 */
1110 dbus_bool_t
_dbus_string_append_printf(DBusString * str,const char * format,...)1111 _dbus_string_append_printf (DBusString *str,
1112 const char *format,
1113 ...)
1114 {
1115 va_list args;
1116 dbus_bool_t retval;
1117
1118 va_start (args, format);
1119 retval = _dbus_string_append_printf_valist (str, format, args);
1120 va_end (args);
1121
1122 return retval;
1123 }
1124
1125 /**
1126 * Appends block of bytes with the given length to a DBusString.
1127 *
1128 * @param str the DBusString
1129 * @param buffer the bytes to append
1130 * @param len the number of bytes to append
1131 * @returns #FALSE if not enough memory.
1132 */
1133 dbus_bool_t
_dbus_string_append_len(DBusString * str,const char * buffer,int len)1134 _dbus_string_append_len (DBusString *str,
1135 const char *buffer,
1136 int len)
1137 {
1138 DBUS_STRING_PREAMBLE (str);
1139 _dbus_assert (buffer != NULL);
1140 _dbus_assert (len >= 0);
1141
1142 return append (real, buffer, len);
1143 }
1144
1145 /**
1146 * Appends a single byte to the string, returning #FALSE
1147 * if not enough memory.
1148 *
1149 * @param str the string
1150 * @param byte the byte to append
1151 * @returns #TRUE on success
1152 */
1153 dbus_bool_t
_dbus_string_append_byte(DBusString * str,unsigned char byte)1154 _dbus_string_append_byte (DBusString *str,
1155 unsigned char byte)
1156 {
1157 DBUS_STRING_PREAMBLE (str);
1158
1159 if (!set_length (real, real->len + 1))
1160 return FALSE;
1161
1162 real->str[real->len-1] = byte;
1163
1164 return TRUE;
1165 }
1166
1167 static void
delete(DBusRealString * real,int start,int len)1168 delete (DBusRealString *real,
1169 int start,
1170 int len)
1171 {
1172 if (len == 0)
1173 return;
1174
1175 memmove (real->str + start, real->str + start + len, real->len - (start + len));
1176 real->len -= len;
1177 real->str[real->len] = '\0';
1178 }
1179
1180 /**
1181 * Deletes a segment of a DBusString with length len starting at
1182 * start. (Hint: to clear an entire string, setting length to 0
1183 * with _dbus_string_set_length() is easier.)
1184 *
1185 * @param str the DBusString
1186 * @param start where to start deleting
1187 * @param len the number of bytes to delete
1188 */
1189 void
_dbus_string_delete(DBusString * str,int start,int len)1190 _dbus_string_delete (DBusString *str,
1191 int start,
1192 int len)
1193 {
1194 DBUS_STRING_PREAMBLE (str);
1195 _dbus_assert (start >= 0);
1196 _dbus_assert (len >= 0);
1197 _dbus_assert (start <= real->len);
1198 _dbus_assert (len <= real->len - start);
1199
1200 delete (real, start, len);
1201 }
1202
1203 static dbus_bool_t
copy(DBusRealString * source,int start,int len,DBusRealString * dest,int insert_at)1204 copy (DBusRealString *source,
1205 int start,
1206 int len,
1207 DBusRealString *dest,
1208 int insert_at)
1209 {
1210 if (len == 0)
1211 return TRUE;
1212
1213 if (!open_gap (len, dest, insert_at))
1214 return FALSE;
1215
1216 memmove (dest->str + insert_at,
1217 source->str + start,
1218 len);
1219
1220 return TRUE;
1221 }
1222
1223 /**
1224 * Checks assertions for two strings we're copying a segment between,
1225 * and declares real_source/real_dest variables.
1226 *
1227 * @param source the source string
1228 * @param start the starting offset
1229 * @param dest the dest string
1230 * @param insert_at where the copied segment is inserted
1231 */
1232 #define DBUS_STRING_COPY_PREAMBLE(source, start, dest, insert_at) \
1233 DBusRealString *real_source = (DBusRealString*) source; \
1234 DBusRealString *real_dest = (DBusRealString*) dest; \
1235 _dbus_assert ((source) != (dest)); \
1236 DBUS_GENERIC_STRING_PREAMBLE (real_source); \
1237 DBUS_GENERIC_STRING_PREAMBLE (real_dest); \
1238 _dbus_assert (!real_dest->constant); \
1239 _dbus_assert (!real_dest->locked); \
1240 _dbus_assert ((start) >= 0); \
1241 _dbus_assert ((start) <= real_source->len); \
1242 _dbus_assert ((insert_at) >= 0); \
1243 _dbus_assert ((insert_at) <= real_dest->len)
1244
1245 /**
1246 * Moves the end of one string into another string. Both strings
1247 * must be initialized, valid strings.
1248 *
1249 * @param source the source string
1250 * @param start where to chop off the source string
1251 * @param dest the destination string
1252 * @param insert_at where to move the chopped-off part of source string
1253 * @returns #FALSE if not enough memory
1254 */
1255 dbus_bool_t
_dbus_string_move(DBusString * source,int start,DBusString * dest,int insert_at)1256 _dbus_string_move (DBusString *source,
1257 int start,
1258 DBusString *dest,
1259 int insert_at)
1260 {
1261 DBusRealString *real_source = (DBusRealString*) source;
1262 _dbus_assert (start <= real_source->len);
1263
1264 return _dbus_string_move_len (source, start,
1265 real_source->len - start,
1266 dest, insert_at);
1267 }
1268
1269 /**
1270 * Like _dbus_string_move(), but does not delete the section
1271 * of the source string that's copied to the dest string.
1272 *
1273 * @param source the source string
1274 * @param start where to start copying the source string
1275 * @param dest the destination string
1276 * @param insert_at where to place the copied part of source string
1277 * @returns #FALSE if not enough memory
1278 */
1279 dbus_bool_t
_dbus_string_copy(const DBusString * source,int start,DBusString * dest,int insert_at)1280 _dbus_string_copy (const DBusString *source,
1281 int start,
1282 DBusString *dest,
1283 int insert_at)
1284 {
1285 DBUS_STRING_COPY_PREAMBLE (source, start, dest, insert_at);
1286
1287 return copy (real_source, start,
1288 real_source->len - start,
1289 real_dest,
1290 insert_at);
1291 }
1292
1293 /**
1294 * Like _dbus_string_move(), but can move a segment from
1295 * the middle of the source string.
1296 *
1297 * @param source the source string
1298 * @param start first byte of source string to move
1299 * @param len length of segment to move
1300 * @param dest the destination string
1301 * @param insert_at where to move the bytes from the source string
1302 * @returns #FALSE if not enough memory
1303 */
1304 dbus_bool_t
_dbus_string_move_len(DBusString * source,int start,int len,DBusString * dest,int insert_at)1305 _dbus_string_move_len (DBusString *source,
1306 int start,
1307 int len,
1308 DBusString *dest,
1309 int insert_at)
1310
1311 {
1312 DBUS_STRING_COPY_PREAMBLE (source, start, dest, insert_at);
1313 _dbus_assert (len >= 0);
1314 _dbus_assert ((start + len) <= real_source->len);
1315
1316
1317 if (len == 0)
1318 {
1319 return TRUE;
1320 }
1321 else if (start == 0 &&
1322 len == real_source->len &&
1323 real_dest->len == 0)
1324 {
1325 /* Short-circuit moving an entire existing string to an empty string
1326 * by just swapping the buffers.
1327 */
1328 /* we assume ->constant doesn't matter as you can't have
1329 * a constant string involved in a move.
1330 */
1331 #define ASSIGN_DATA(a, b) do { \
1332 (a)->str = (b)->str; \
1333 (a)->len = (b)->len; \
1334 (a)->allocated = (b)->allocated; \
1335 (a)->align_offset = (b)->align_offset; \
1336 } while (0)
1337
1338 DBusRealString tmp;
1339
1340 ASSIGN_DATA (&tmp, real_source);
1341 ASSIGN_DATA (real_source, real_dest);
1342 ASSIGN_DATA (real_dest, &tmp);
1343
1344 return TRUE;
1345 }
1346 else
1347 {
1348 if (!copy (real_source, start, len,
1349 real_dest,
1350 insert_at))
1351 return FALSE;
1352
1353 delete (real_source, start,
1354 len);
1355
1356 return TRUE;
1357 }
1358 }
1359
1360 /**
1361 * Like _dbus_string_copy(), but can copy a segment from the middle of
1362 * the source string.
1363 *
1364 * @param source the source string
1365 * @param start where to start copying the source string
1366 * @param len length of segment to copy
1367 * @param dest the destination string
1368 * @param insert_at where to place the copied segment of source string
1369 * @returns #FALSE if not enough memory
1370 */
1371 dbus_bool_t
_dbus_string_copy_len(const DBusString * source,int start,int len,DBusString * dest,int insert_at)1372 _dbus_string_copy_len (const DBusString *source,
1373 int start,
1374 int len,
1375 DBusString *dest,
1376 int insert_at)
1377 {
1378 DBUS_STRING_COPY_PREAMBLE (source, start, dest, insert_at);
1379 _dbus_assert (len >= 0);
1380 _dbus_assert (start <= real_source->len);
1381 _dbus_assert (len <= real_source->len - start);
1382
1383 return copy (real_source, start, len,
1384 real_dest,
1385 insert_at);
1386 }
1387
1388 /**
1389 * Replaces a segment of dest string with a segment of source string.
1390 *
1391 * @param source the source string
1392 * @param start where to start copying the source string
1393 * @param len length of segment to copy
1394 * @param dest the destination string
1395 * @param replace_at start of segment of dest string to replace
1396 * @param replace_len length of segment of dest string to replace
1397 * @returns #FALSE if not enough memory
1398 *
1399 */
1400 dbus_bool_t
_dbus_string_replace_len(const DBusString * source,int start,int len,DBusString * dest,int replace_at,int replace_len)1401 _dbus_string_replace_len (const DBusString *source,
1402 int start,
1403 int len,
1404 DBusString *dest,
1405 int replace_at,
1406 int replace_len)
1407 {
1408 DBUS_STRING_COPY_PREAMBLE (source, start, dest, replace_at);
1409 _dbus_assert (len >= 0);
1410 _dbus_assert (start <= real_source->len);
1411 _dbus_assert (len <= real_source->len - start);
1412 _dbus_assert (replace_at >= 0);
1413 _dbus_assert (replace_at <= real_dest->len);
1414 _dbus_assert (replace_len <= real_dest->len - replace_at);
1415
1416 if (len == replace_len)
1417 {
1418 memmove (real_dest->str + replace_at,
1419 real_source->str + start, len);
1420 }
1421 else if (len < replace_len)
1422 {
1423 memmove (real_dest->str + replace_at,
1424 real_source->str + start, len);
1425 delete (real_dest, replace_at + len,
1426 replace_len - len);
1427 }
1428 else
1429 {
1430 int diff;
1431
1432 _dbus_assert (len > replace_len);
1433
1434 diff = len - replace_len;
1435
1436 /* First of all we check if destination string can be enlarged as
1437 * required, then we overwrite previous bytes
1438 */
1439
1440 if (!copy (real_source, start + replace_len, diff,
1441 real_dest, replace_at + replace_len))
1442 return FALSE;
1443
1444 memmove (real_dest->str + replace_at,
1445 real_source->str + start, replace_len);
1446 }
1447
1448 return TRUE;
1449 }
1450
1451 /**
1452 * Looks for the first occurance of a byte, deletes that byte,
1453 * and moves everything after the byte to the beginning of a
1454 * separate string. Both strings must be initialized, valid
1455 * strings.
1456 *
1457 * @param source the source string
1458 * @param byte the byte to remove and split the string at
1459 * @param tail the split off string
1460 * @returns #FALSE if not enough memory or if byte could not be found
1461 *
1462 */
1463 dbus_bool_t
_dbus_string_split_on_byte(DBusString * source,unsigned char byte,DBusString * tail)1464 _dbus_string_split_on_byte (DBusString *source,
1465 unsigned char byte,
1466 DBusString *tail)
1467 {
1468 int byte_position;
1469 char byte_string[2] = "";
1470 int head_length;
1471 int tail_length;
1472
1473 byte_string[0] = (char) byte;
1474
1475 if (!_dbus_string_find (source, 0, byte_string, &byte_position))
1476 return FALSE;
1477
1478 head_length = byte_position;
1479 tail_length = _dbus_string_get_length (source) - head_length - 1;
1480
1481 if (!_dbus_string_move_len (source, byte_position + 1, tail_length,
1482 tail, 0))
1483 return FALSE;
1484
1485 /* remove the trailing delimiter byte from the head now.
1486 */
1487 if (!_dbus_string_set_length (source, head_length))
1488 return FALSE;
1489
1490 return TRUE;
1491 }
1492
1493 /* Unicode macros and utf8_validate() from GLib Owen Taylor, Havoc
1494 * Pennington, and Tom Tromey are the authors and authorized relicense.
1495 */
1496
1497 /** computes length and mask of a unicode character
1498 * @param Char the char
1499 * @param Mask the mask variable to assign to
1500 * @param Len the length variable to assign to
1501 */
1502 #define UTF8_COMPUTE(Char, Mask, Len) \
1503 if (Char < 128) \
1504 { \
1505 Len = 1; \
1506 Mask = 0x7f; \
1507 } \
1508 else if ((Char & 0xe0) == 0xc0) \
1509 { \
1510 Len = 2; \
1511 Mask = 0x1f; \
1512 } \
1513 else if ((Char & 0xf0) == 0xe0) \
1514 { \
1515 Len = 3; \
1516 Mask = 0x0f; \
1517 } \
1518 else if ((Char & 0xf8) == 0xf0) \
1519 { \
1520 Len = 4; \
1521 Mask = 0x07; \
1522 } \
1523 else if ((Char & 0xfc) == 0xf8) \
1524 { \
1525 Len = 5; \
1526 Mask = 0x03; \
1527 } \
1528 else if ((Char & 0xfe) == 0xfc) \
1529 { \
1530 Len = 6; \
1531 Mask = 0x01; \
1532 } \
1533 else \
1534 { \
1535 Len = 0; \
1536 Mask = 0; \
1537 }
1538
1539 /**
1540 * computes length of a unicode character in UTF-8
1541 * @param Char the char
1542 */
1543 #define UTF8_LENGTH(Char) \
1544 ((Char) < 0x80 ? 1 : \
1545 ((Char) < 0x800 ? 2 : \
1546 ((Char) < 0x10000 ? 3 : \
1547 ((Char) < 0x200000 ? 4 : \
1548 ((Char) < 0x4000000 ? 5 : 6)))))
1549
1550 /**
1551 * Gets a UTF-8 value.
1552 *
1553 * @param Result variable for extracted unicode char.
1554 * @param Chars the bytes to decode
1555 * @param Count counter variable
1556 * @param Mask mask for this char
1557 * @param Len length for this char in bytes
1558 */
1559 #define UTF8_GET(Result, Chars, Count, Mask, Len) \
1560 (Result) = (Chars)[0] & (Mask); \
1561 for ((Count) = 1; (Count) < (Len); ++(Count)) \
1562 { \
1563 if (((Chars)[(Count)] & 0xc0) != 0x80) \
1564 { \
1565 (Result) = -1; \
1566 break; \
1567 } \
1568 (Result) <<= 6; \
1569 (Result) |= ((Chars)[(Count)] & 0x3f); \
1570 }
1571
1572 /**
1573 * Check whether a Unicode (5.2) char is in a valid range.
1574 *
1575 * The first check comes from the Unicode guarantee to never encode
1576 * a point above 0x0010ffff, since UTF-16 couldn't represent it.
1577 *
1578 * The second check covers surrogate pairs (category Cs).
1579 *
1580 * The last two checks cover "Noncharacter": defined as:
1581 * "A code point that is permanently reserved for
1582 * internal use, and that should never be interchanged. In
1583 * Unicode 3.1, these consist of the values U+nFFFE and U+nFFFF
1584 * (where n is from 0 to 10_16) and the values U+FDD0..U+FDEF."
1585 *
1586 * @param Char the character
1587 */
1588 #define UNICODE_VALID(Char) \
1589 ((Char) < 0x110000 && \
1590 (((Char) & 0xFFFFF800) != 0xD800) && \
1591 ((Char) < 0xFDD0 || (Char) > 0xFDEF) && \
1592 ((Char) & 0xFFFE) != 0xFFFE)
1593
1594 /**
1595 * Finds the given substring in the string,
1596 * returning #TRUE and filling in the byte index
1597 * where the substring was found, if it was found.
1598 * Returns #FALSE if the substring wasn't found.
1599 * Sets *start to the length of the string if the substring
1600 * is not found.
1601 *
1602 * @param str the string
1603 * @param start where to start looking
1604 * @param substr the substring
1605 * @param found return location for where it was found, or #NULL
1606 * @returns #TRUE if found
1607 */
1608 dbus_bool_t
_dbus_string_find(const DBusString * str,int start,const char * substr,int * found)1609 _dbus_string_find (const DBusString *str,
1610 int start,
1611 const char *substr,
1612 int *found)
1613 {
1614 return _dbus_string_find_to (str, start,
1615 ((const DBusRealString*)str)->len,
1616 substr, found);
1617 }
1618
1619 /**
1620 * Finds end of line ("\r\n" or "\n") in the string,
1621 * returning #TRUE and filling in the byte index
1622 * where the eol string was found, if it was found.
1623 * Returns #FALSE if eol wasn't found.
1624 *
1625 * @param str the string
1626 * @param start where to start looking
1627 * @param found return location for where eol was found or string length otherwise
1628 * @param found_len return length of found eol string or zero otherwise
1629 * @returns #TRUE if found
1630 */
1631 dbus_bool_t
_dbus_string_find_eol(const DBusString * str,int start,int * found,int * found_len)1632 _dbus_string_find_eol (const DBusString *str,
1633 int start,
1634 int *found,
1635 int *found_len)
1636 {
1637 int i;
1638
1639 DBUS_CONST_STRING_PREAMBLE (str);
1640 _dbus_assert (start <= real->len);
1641 _dbus_assert (start >= 0);
1642
1643 i = start;
1644 while (i < real->len)
1645 {
1646 if (real->str[i] == '\r')
1647 {
1648 if ((i+1) < real->len && real->str[i+1] == '\n') /* "\r\n" */
1649 {
1650 if (found)
1651 *found = i;
1652 if (found_len)
1653 *found_len = 2;
1654 return TRUE;
1655 }
1656 else /* only "\r" */
1657 {
1658 if (found)
1659 *found = i;
1660 if (found_len)
1661 *found_len = 1;
1662 return TRUE;
1663 }
1664 }
1665 else if (real->str[i] == '\n') /* only "\n" */
1666 {
1667 if (found)
1668 *found = i;
1669 if (found_len)
1670 *found_len = 1;
1671 return TRUE;
1672 }
1673 ++i;
1674 }
1675
1676 if (found)
1677 *found = real->len;
1678
1679 if (found_len)
1680 *found_len = 0;
1681
1682 return FALSE;
1683 }
1684
1685 /**
1686 * Finds the given substring in the string,
1687 * up to a certain position,
1688 * returning #TRUE and filling in the byte index
1689 * where the substring was found, if it was found.
1690 * Returns #FALSE if the substring wasn't found.
1691 * Sets *start to the length of the string if the substring
1692 * is not found.
1693 *
1694 * @param str the string
1695 * @param start where to start looking
1696 * @param end where to stop looking
1697 * @param substr the substring
1698 * @param found return location for where it was found, or #NULL
1699 * @returns #TRUE if found
1700 */
1701 dbus_bool_t
_dbus_string_find_to(const DBusString * str,int start,int end,const char * substr,int * found)1702 _dbus_string_find_to (const DBusString *str,
1703 int start,
1704 int end,
1705 const char *substr,
1706 int *found)
1707 {
1708 int i;
1709 DBUS_CONST_STRING_PREAMBLE (str);
1710 _dbus_assert (substr != NULL);
1711 _dbus_assert (start <= real->len);
1712 _dbus_assert (start >= 0);
1713 _dbus_assert (substr != NULL);
1714 _dbus_assert (end <= real->len);
1715 _dbus_assert (start <= end);
1716
1717 /* we always "find" an empty string */
1718 if (*substr == '\0')
1719 {
1720 if (found)
1721 *found = start;
1722 return TRUE;
1723 }
1724
1725 i = start;
1726 while (i < end)
1727 {
1728 if (real->str[i] == substr[0])
1729 {
1730 int j = i + 1;
1731
1732 while (j < end)
1733 {
1734 if (substr[j - i] == '\0')
1735 break;
1736 else if (real->str[j] != substr[j - i])
1737 break;
1738
1739 ++j;
1740 }
1741
1742 if (substr[j - i] == '\0')
1743 {
1744 if (found)
1745 *found = i;
1746 return TRUE;
1747 }
1748 }
1749
1750 ++i;
1751 }
1752
1753 if (found)
1754 *found = end;
1755
1756 return FALSE;
1757 }
1758
1759 /**
1760 * Finds a blank (space or tab) in the string. Returns #TRUE
1761 * if found, #FALSE otherwise. If a blank is not found sets
1762 * *found to the length of the string.
1763 *
1764 * @param str the string
1765 * @param start byte index to start looking
1766 * @param found place to store the location of the first blank
1767 * @returns #TRUE if a blank was found
1768 */
1769 dbus_bool_t
_dbus_string_find_blank(const DBusString * str,int start,int * found)1770 _dbus_string_find_blank (const DBusString *str,
1771 int start,
1772 int *found)
1773 {
1774 int i;
1775 DBUS_CONST_STRING_PREAMBLE (str);
1776 _dbus_assert (start <= real->len);
1777 _dbus_assert (start >= 0);
1778
1779 i = start;
1780 while (i < real->len)
1781 {
1782 if (real->str[i] == ' ' ||
1783 real->str[i] == '\t')
1784 {
1785 if (found)
1786 *found = i;
1787 return TRUE;
1788 }
1789
1790 ++i;
1791 }
1792
1793 if (found)
1794 *found = real->len;
1795
1796 return FALSE;
1797 }
1798
1799 /**
1800 * Skips blanks from start, storing the first non-blank in *end
1801 * (blank is space or tab).
1802 *
1803 * @param str the string
1804 * @param start where to start
1805 * @param end where to store the first non-blank byte index
1806 */
1807 void
_dbus_string_skip_blank(const DBusString * str,int start,int * end)1808 _dbus_string_skip_blank (const DBusString *str,
1809 int start,
1810 int *end)
1811 {
1812 int i;
1813 DBUS_CONST_STRING_PREAMBLE (str);
1814 _dbus_assert (start <= real->len);
1815 _dbus_assert (start >= 0);
1816
1817 i = start;
1818 while (i < real->len)
1819 {
1820 if (!DBUS_IS_ASCII_BLANK (real->str[i]))
1821 break;
1822
1823 ++i;
1824 }
1825
1826 _dbus_assert (i == real->len || !DBUS_IS_ASCII_WHITE (real->str[i]));
1827
1828 if (end)
1829 *end = i;
1830 }
1831
1832
1833 /**
1834 * Skips whitespace from start, storing the first non-whitespace in *end.
1835 * (whitespace is space, tab, newline, CR).
1836 *
1837 * @param str the string
1838 * @param start where to start
1839 * @param end where to store the first non-whitespace byte index
1840 */
1841 void
_dbus_string_skip_white(const DBusString * str,int start,int * end)1842 _dbus_string_skip_white (const DBusString *str,
1843 int start,
1844 int *end)
1845 {
1846 int i;
1847 DBUS_CONST_STRING_PREAMBLE (str);
1848 _dbus_assert (start <= real->len);
1849 _dbus_assert (start >= 0);
1850
1851 i = start;
1852 while (i < real->len)
1853 {
1854 if (!DBUS_IS_ASCII_WHITE (real->str[i]))
1855 break;
1856
1857 ++i;
1858 }
1859
1860 _dbus_assert (i == real->len || !(DBUS_IS_ASCII_WHITE (real->str[i])));
1861
1862 if (end)
1863 *end = i;
1864 }
1865
1866 /**
1867 * Skips whitespace from end, storing the start index of the trailing
1868 * whitespace in *start. (whitespace is space, tab, newline, CR).
1869 *
1870 * @param str the string
1871 * @param end where to start scanning backward
1872 * @param start where to store the start of whitespace chars
1873 */
1874 void
_dbus_string_skip_white_reverse(const DBusString * str,int end,int * start)1875 _dbus_string_skip_white_reverse (const DBusString *str,
1876 int end,
1877 int *start)
1878 {
1879 int i;
1880 DBUS_CONST_STRING_PREAMBLE (str);
1881 _dbus_assert (end <= real->len);
1882 _dbus_assert (end >= 0);
1883
1884 i = end;
1885 while (i > 0)
1886 {
1887 if (!DBUS_IS_ASCII_WHITE (real->str[i-1]))
1888 break;
1889 --i;
1890 }
1891
1892 _dbus_assert (i >= 0 && (i == 0 || !(DBUS_IS_ASCII_WHITE (real->str[i-1]))));
1893
1894 if (start)
1895 *start = i;
1896 }
1897
1898 /**
1899 * Assigns a newline-terminated or \\r\\n-terminated line from the front
1900 * of the string to the given dest string. The dest string's previous
1901 * contents are deleted. If the source string contains no newline,
1902 * moves the entire source string to the dest string.
1903 *
1904 * @todo owen correctly notes that this is a stupid function (it was
1905 * written purely for test code,
1906 * e.g. dbus-message-builder.c). Probably should be enforced as test
1907 * code only with ifdef DBUS_BUILD_TESTS
1908 *
1909 * @param source the source string
1910 * @param dest the destination string (contents are replaced)
1911 * @returns #FALSE if no memory, or source has length 0
1912 */
1913 dbus_bool_t
_dbus_string_pop_line(DBusString * source,DBusString * dest)1914 _dbus_string_pop_line (DBusString *source,
1915 DBusString *dest)
1916 {
1917 int eol, eol_len;
1918
1919 _dbus_string_set_length (dest, 0);
1920
1921 eol = 0;
1922 eol_len = 0;
1923 if (!_dbus_string_find_eol (source, 0, &eol, &eol_len))
1924 {
1925 _dbus_assert (eol == _dbus_string_get_length (source));
1926 if (eol == 0)
1927 {
1928 /* If there's no newline and source has zero length, we're done */
1929 return FALSE;
1930 }
1931 /* otherwise, the last line of the file has no eol characters */
1932 }
1933
1934 /* remember eol can be 0 if it's an empty line, but eol_len should not be zero also
1935 * since find_eol returned TRUE
1936 */
1937
1938 if (!_dbus_string_move_len (source, 0, eol + eol_len, dest, 0))
1939 return FALSE;
1940
1941 /* remove line ending */
1942 if (!_dbus_string_set_length (dest, eol))
1943 {
1944 _dbus_assert_not_reached ("out of memory when shortening a string");
1945 return FALSE;
1946 }
1947
1948 return TRUE;
1949 }
1950
1951 #ifdef DBUS_BUILD_TESTS
1952 /**
1953 * Deletes up to and including the first blank space
1954 * in the string.
1955 *
1956 * @param str the string
1957 */
1958 void
_dbus_string_delete_first_word(DBusString * str)1959 _dbus_string_delete_first_word (DBusString *str)
1960 {
1961 int i;
1962
1963 if (_dbus_string_find_blank (str, 0, &i))
1964 _dbus_string_skip_blank (str, i, &i);
1965
1966 _dbus_string_delete (str, 0, i);
1967 }
1968 #endif
1969
1970 #ifdef DBUS_BUILD_TESTS
1971 /**
1972 * Deletes any leading blanks in the string
1973 *
1974 * @param str the string
1975 */
1976 void
_dbus_string_delete_leading_blanks(DBusString * str)1977 _dbus_string_delete_leading_blanks (DBusString *str)
1978 {
1979 int i;
1980
1981 _dbus_string_skip_blank (str, 0, &i);
1982
1983 if (i > 0)
1984 _dbus_string_delete (str, 0, i);
1985 }
1986 #endif
1987
1988 /**
1989 * Deletes leading and trailing whitespace
1990 *
1991 * @param str the string
1992 */
1993 void
_dbus_string_chop_white(DBusString * str)1994 _dbus_string_chop_white(DBusString *str)
1995 {
1996 int i;
1997
1998 _dbus_string_skip_white (str, 0, &i);
1999
2000 if (i > 0)
2001 _dbus_string_delete (str, 0, i);
2002
2003 _dbus_string_skip_white_reverse (str, _dbus_string_get_length (str), &i);
2004
2005 _dbus_string_set_length (str, i);
2006 }
2007
2008 /**
2009 * Tests two DBusString for equality.
2010 *
2011 * @todo memcmp is probably faster
2012 *
2013 * @param a first string
2014 * @param b second string
2015 * @returns #TRUE if equal
2016 */
2017 dbus_bool_t
_dbus_string_equal(const DBusString * a,const DBusString * b)2018 _dbus_string_equal (const DBusString *a,
2019 const DBusString *b)
2020 {
2021 const unsigned char *ap;
2022 const unsigned char *bp;
2023 const unsigned char *a_end;
2024 const DBusRealString *real_a = (const DBusRealString*) a;
2025 const DBusRealString *real_b = (const DBusRealString*) b;
2026 DBUS_GENERIC_STRING_PREAMBLE (real_a);
2027 DBUS_GENERIC_STRING_PREAMBLE (real_b);
2028
2029 if (real_a->len != real_b->len)
2030 return FALSE;
2031
2032 ap = real_a->str;
2033 bp = real_b->str;
2034 a_end = real_a->str + real_a->len;
2035 while (ap != a_end)
2036 {
2037 if (*ap != *bp)
2038 return FALSE;
2039
2040 ++ap;
2041 ++bp;
2042 }
2043
2044 return TRUE;
2045 }
2046
2047 /**
2048 * Tests two DBusString for equality up to the given length.
2049 * The strings may be shorter than the given length.
2050 *
2051 * @todo write a unit test
2052 *
2053 * @todo memcmp is probably faster
2054 *
2055 * @param a first string
2056 * @param b second string
2057 * @param len the maximum length to look at
2058 * @returns #TRUE if equal for the given number of bytes
2059 */
2060 dbus_bool_t
_dbus_string_equal_len(const DBusString * a,const DBusString * b,int len)2061 _dbus_string_equal_len (const DBusString *a,
2062 const DBusString *b,
2063 int len)
2064 {
2065 const unsigned char *ap;
2066 const unsigned char *bp;
2067 const unsigned char *a_end;
2068 const DBusRealString *real_a = (const DBusRealString*) a;
2069 const DBusRealString *real_b = (const DBusRealString*) b;
2070 DBUS_GENERIC_STRING_PREAMBLE (real_a);
2071 DBUS_GENERIC_STRING_PREAMBLE (real_b);
2072
2073 if (real_a->len != real_b->len &&
2074 (real_a->len < len || real_b->len < len))
2075 return FALSE;
2076
2077 ap = real_a->str;
2078 bp = real_b->str;
2079 a_end = real_a->str + MIN (real_a->len, len);
2080 while (ap != a_end)
2081 {
2082 if (*ap != *bp)
2083 return FALSE;
2084
2085 ++ap;
2086 ++bp;
2087 }
2088
2089 return TRUE;
2090 }
2091
2092 /**
2093 * Tests two sub-parts of two DBusString for equality. The specified
2094 * range of the first string must exist; the specified start position
2095 * of the second string must exist.
2096 *
2097 * @todo write a unit test
2098 *
2099 * @todo memcmp is probably faster
2100 *
2101 * @param a first string
2102 * @param a_start where to start substring in first string
2103 * @param a_len length of substring in first string
2104 * @param b second string
2105 * @param b_start where to start substring in second string
2106 * @returns #TRUE if the two substrings are equal
2107 */
2108 dbus_bool_t
_dbus_string_equal_substring(const DBusString * a,int a_start,int a_len,const DBusString * b,int b_start)2109 _dbus_string_equal_substring (const DBusString *a,
2110 int a_start,
2111 int a_len,
2112 const DBusString *b,
2113 int b_start)
2114 {
2115 const unsigned char *ap;
2116 const unsigned char *bp;
2117 const unsigned char *a_end;
2118 const DBusRealString *real_a = (const DBusRealString*) a;
2119 const DBusRealString *real_b = (const DBusRealString*) b;
2120 DBUS_GENERIC_STRING_PREAMBLE (real_a);
2121 DBUS_GENERIC_STRING_PREAMBLE (real_b);
2122 _dbus_assert (a_start >= 0);
2123 _dbus_assert (a_len >= 0);
2124 _dbus_assert (a_start <= real_a->len);
2125 _dbus_assert (a_len <= real_a->len - a_start);
2126 _dbus_assert (b_start >= 0);
2127 _dbus_assert (b_start <= real_b->len);
2128
2129 if (a_len > real_b->len - b_start)
2130 return FALSE;
2131
2132 ap = real_a->str + a_start;
2133 bp = real_b->str + b_start;
2134 a_end = ap + a_len;
2135 while (ap != a_end)
2136 {
2137 if (*ap != *bp)
2138 return FALSE;
2139
2140 ++ap;
2141 ++bp;
2142 }
2143
2144 _dbus_assert (bp <= (real_b->str + real_b->len));
2145
2146 return TRUE;
2147 }
2148
2149 /**
2150 * Checks whether a string is equal to a C string.
2151 *
2152 * @param a the string
2153 * @param c_str the C string
2154 * @returns #TRUE if equal
2155 */
2156 dbus_bool_t
_dbus_string_equal_c_str(const DBusString * a,const char * c_str)2157 _dbus_string_equal_c_str (const DBusString *a,
2158 const char *c_str)
2159 {
2160 const unsigned char *ap;
2161 const unsigned char *bp;
2162 const unsigned char *a_end;
2163 const DBusRealString *real_a = (const DBusRealString*) a;
2164 DBUS_GENERIC_STRING_PREAMBLE (real_a);
2165 _dbus_assert (c_str != NULL);
2166
2167 ap = real_a->str;
2168 bp = (const unsigned char*) c_str;
2169 a_end = real_a->str + real_a->len;
2170 while (ap != a_end && *bp)
2171 {
2172 if (*ap != *bp)
2173 return FALSE;
2174
2175 ++ap;
2176 ++bp;
2177 }
2178
2179 if (ap != a_end || *bp)
2180 return FALSE;
2181
2182 return TRUE;
2183 }
2184
2185 /**
2186 * Checks whether a string starts with the given C string.
2187 *
2188 * @param a the string
2189 * @param c_str the C string
2190 * @returns #TRUE if string starts with it
2191 */
2192 dbus_bool_t
_dbus_string_starts_with_c_str(const DBusString * a,const char * c_str)2193 _dbus_string_starts_with_c_str (const DBusString *a,
2194 const char *c_str)
2195 {
2196 const unsigned char *ap;
2197 const unsigned char *bp;
2198 const unsigned char *a_end;
2199 const DBusRealString *real_a = (const DBusRealString*) a;
2200 DBUS_GENERIC_STRING_PREAMBLE (real_a);
2201 _dbus_assert (c_str != NULL);
2202
2203 ap = real_a->str;
2204 bp = (const unsigned char*) c_str;
2205 a_end = real_a->str + real_a->len;
2206 while (ap != a_end && *bp)
2207 {
2208 if (*ap != *bp)
2209 return FALSE;
2210
2211 ++ap;
2212 ++bp;
2213 }
2214
2215 if (*bp == '\0')
2216 return TRUE;
2217 else
2218 return FALSE;
2219 }
2220
2221 /**
2222 * Appends a two-character hex digit to a string, where the hex digit
2223 * has the value of the given byte.
2224 *
2225 * @param str the string
2226 * @param byte the byte
2227 * @returns #FALSE if no memory
2228 */
2229 dbus_bool_t
_dbus_string_append_byte_as_hex(DBusString * str,int byte)2230 _dbus_string_append_byte_as_hex (DBusString *str,
2231 int byte)
2232 {
2233 const char hexdigits[16] = {
2234 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
2235 'a', 'b', 'c', 'd', 'e', 'f'
2236 };
2237
2238 if (!_dbus_string_append_byte (str,
2239 hexdigits[(byte >> 4)]))
2240 return FALSE;
2241
2242 if (!_dbus_string_append_byte (str,
2243 hexdigits[(byte & 0x0f)]))
2244 {
2245 _dbus_string_set_length (str,
2246 _dbus_string_get_length (str) - 1);
2247 return FALSE;
2248 }
2249
2250 return TRUE;
2251 }
2252
2253 /**
2254 * Encodes a string in hex, the way MD5 and SHA-1 are usually
2255 * encoded. (Each byte is two hex digits.)
2256 *
2257 * @param source the string to encode
2258 * @param start byte index to start encoding
2259 * @param dest string where encoded data should be placed
2260 * @param insert_at where to place encoded data
2261 * @returns #TRUE if encoding was successful, #FALSE if no memory etc.
2262 */
2263 dbus_bool_t
_dbus_string_hex_encode(const DBusString * source,int start,DBusString * dest,int insert_at)2264 _dbus_string_hex_encode (const DBusString *source,
2265 int start,
2266 DBusString *dest,
2267 int insert_at)
2268 {
2269 DBusString result;
2270 const unsigned char *p;
2271 const unsigned char *end;
2272 dbus_bool_t retval;
2273
2274 _dbus_assert (start <= _dbus_string_get_length (source));
2275
2276 if (!_dbus_string_init (&result))
2277 return FALSE;
2278
2279 retval = FALSE;
2280
2281 p = (const unsigned char*) _dbus_string_get_const_data (source);
2282 end = p + _dbus_string_get_length (source);
2283 p += start;
2284
2285 while (p != end)
2286 {
2287 if (!_dbus_string_append_byte_as_hex (&result, *p))
2288 goto out;
2289
2290 ++p;
2291 }
2292
2293 if (!_dbus_string_move (&result, 0, dest, insert_at))
2294 goto out;
2295
2296 retval = TRUE;
2297
2298 out:
2299 _dbus_string_free (&result);
2300 return retval;
2301 }
2302
2303 /**
2304 * Decodes a string from hex encoding.
2305 *
2306 * @param source the string to decode
2307 * @param start byte index to start decode
2308 * @param end_return return location of the end of the hex data, or #NULL
2309 * @param dest string where decoded data should be placed
2310 * @param insert_at where to place decoded data
2311 * @returns #TRUE if decoding was successful, #FALSE if no memory.
2312 */
2313 dbus_bool_t
_dbus_string_hex_decode(const DBusString * source,int start,int * end_return,DBusString * dest,int insert_at)2314 _dbus_string_hex_decode (const DBusString *source,
2315 int start,
2316 int *end_return,
2317 DBusString *dest,
2318 int insert_at)
2319 {
2320 DBusString result;
2321 const unsigned char *p;
2322 const unsigned char *end;
2323 dbus_bool_t retval;
2324 dbus_bool_t high_bits;
2325
2326 _dbus_assert (start <= _dbus_string_get_length (source));
2327
2328 if (!_dbus_string_init (&result))
2329 return FALSE;
2330
2331 retval = FALSE;
2332
2333 high_bits = TRUE;
2334 p = (const unsigned char*) _dbus_string_get_const_data (source);
2335 end = p + _dbus_string_get_length (source);
2336 p += start;
2337
2338 while (p != end)
2339 {
2340 unsigned int val;
2341
2342 switch (*p)
2343 {
2344 case '0':
2345 val = 0;
2346 break;
2347 case '1':
2348 val = 1;
2349 break;
2350 case '2':
2351 val = 2;
2352 break;
2353 case '3':
2354 val = 3;
2355 break;
2356 case '4':
2357 val = 4;
2358 break;
2359 case '5':
2360 val = 5;
2361 break;
2362 case '6':
2363 val = 6;
2364 break;
2365 case '7':
2366 val = 7;
2367 break;
2368 case '8':
2369 val = 8;
2370 break;
2371 case '9':
2372 val = 9;
2373 break;
2374 case 'a':
2375 case 'A':
2376 val = 10;
2377 break;
2378 case 'b':
2379 case 'B':
2380 val = 11;
2381 break;
2382 case 'c':
2383 case 'C':
2384 val = 12;
2385 break;
2386 case 'd':
2387 case 'D':
2388 val = 13;
2389 break;
2390 case 'e':
2391 case 'E':
2392 val = 14;
2393 break;
2394 case 'f':
2395 case 'F':
2396 val = 15;
2397 break;
2398 default:
2399 goto done;
2400 }
2401
2402 if (high_bits)
2403 {
2404 if (!_dbus_string_append_byte (&result,
2405 val << 4))
2406 goto out;
2407 }
2408 else
2409 {
2410 int len;
2411 unsigned char b;
2412
2413 len = _dbus_string_get_length (&result);
2414
2415 b = _dbus_string_get_byte (&result, len - 1);
2416
2417 b |= val;
2418
2419 _dbus_string_set_byte (&result, len - 1, b);
2420 }
2421
2422 high_bits = !high_bits;
2423
2424 ++p;
2425 }
2426
2427 done:
2428 if (!_dbus_string_move (&result, 0, dest, insert_at))
2429 goto out;
2430
2431 if (end_return)
2432 *end_return = p - (const unsigned char*) _dbus_string_get_const_data (source);
2433
2434 retval = TRUE;
2435
2436 out:
2437 _dbus_string_free (&result);
2438 return retval;
2439 }
2440
2441 /**
2442 * Checks that the given range of the string is valid ASCII with no
2443 * nul bytes. If the given range is not entirely contained in the
2444 * string, returns #FALSE.
2445 *
2446 * @todo this is inconsistent with most of DBusString in that
2447 * it allows a start,len range that extends past the string end.
2448 *
2449 * @param str the string
2450 * @param start first byte index to check
2451 * @param len number of bytes to check
2452 * @returns #TRUE if the byte range exists and is all valid ASCII
2453 */
2454 dbus_bool_t
_dbus_string_validate_ascii(const DBusString * str,int start,int len)2455 _dbus_string_validate_ascii (const DBusString *str,
2456 int start,
2457 int len)
2458 {
2459 const unsigned char *s;
2460 const unsigned char *end;
2461 DBUS_CONST_STRING_PREAMBLE (str);
2462 _dbus_assert (start >= 0);
2463 _dbus_assert (start <= real->len);
2464 _dbus_assert (len >= 0);
2465
2466 if (len > real->len - start)
2467 return FALSE;
2468
2469 s = real->str + start;
2470 end = s + len;
2471 while (s != end)
2472 {
2473 if (_DBUS_UNLIKELY (!_DBUS_ISASCII (*s)))
2474 return FALSE;
2475
2476 ++s;
2477 }
2478
2479 return TRUE;
2480 }
2481
2482 /**
2483 * Converts the given range of the string to lower case.
2484 *
2485 * @param str the string
2486 * @param start first byte index to convert
2487 * @param len number of bytes to convert
2488 */
2489 void
_dbus_string_tolower_ascii(const DBusString * str,int start,int len)2490 _dbus_string_tolower_ascii (const DBusString *str,
2491 int start,
2492 int len)
2493 {
2494 unsigned char *s;
2495 unsigned char *end;
2496 DBUS_STRING_PREAMBLE (str);
2497 _dbus_assert (start >= 0);
2498 _dbus_assert (start <= real->len);
2499 _dbus_assert (len >= 0);
2500 _dbus_assert (len <= real->len - start);
2501
2502 s = real->str + start;
2503 end = s + len;
2504
2505 while (s != end)
2506 {
2507 if (*s >= 'A' && *s <= 'Z')
2508 *s += 'a' - 'A';
2509 ++s;
2510 }
2511 }
2512
2513 /**
2514 * Converts the given range of the string to upper case.
2515 *
2516 * @param str the string
2517 * @param start first byte index to convert
2518 * @param len number of bytes to convert
2519 */
2520 void
_dbus_string_toupper_ascii(const DBusString * str,int start,int len)2521 _dbus_string_toupper_ascii (const DBusString *str,
2522 int start,
2523 int len)
2524 {
2525 unsigned char *s;
2526 unsigned char *end;
2527 DBUS_STRING_PREAMBLE (str);
2528 _dbus_assert (start >= 0);
2529 _dbus_assert (start <= real->len);
2530 _dbus_assert (len >= 0);
2531 _dbus_assert (len <= real->len - start);
2532
2533 s = real->str + start;
2534 end = s + len;
2535
2536 while (s != end)
2537 {
2538 if (*s >= 'a' && *s <= 'z')
2539 *s += 'A' - 'a';
2540 ++s;
2541 }
2542 }
2543
2544 /**
2545 * Checks that the given range of the string is valid UTF-8. If the
2546 * given range is not entirely contained in the string, returns
2547 * #FALSE. If the string contains any nul bytes in the given range,
2548 * returns #FALSE. If the start and start+len are not on character
2549 * boundaries, returns #FALSE.
2550 *
2551 * @todo this is inconsistent with most of DBusString in that
2552 * it allows a start,len range that extends past the string end.
2553 *
2554 * @param str the string
2555 * @param start first byte index to check
2556 * @param len number of bytes to check
2557 * @returns #TRUE if the byte range exists and is all valid UTF-8
2558 */
2559 dbus_bool_t
_dbus_string_validate_utf8(const DBusString * str,int start,int len)2560 _dbus_string_validate_utf8 (const DBusString *str,
2561 int start,
2562 int len)
2563 {
2564 const unsigned char *p;
2565 const unsigned char *end;
2566 DBUS_CONST_STRING_PREAMBLE (str);
2567 _dbus_assert (start >= 0);
2568 _dbus_assert (start <= real->len);
2569 _dbus_assert (len >= 0);
2570
2571 /* we are doing _DBUS_UNLIKELY() here which might be
2572 * dubious in a generic library like GLib, but in D-Bus
2573 * we know we're validating messages and that it would
2574 * only be evil/broken apps that would have invalid
2575 * UTF-8. Also, this function seems to be a performance
2576 * bottleneck in profiles.
2577 */
2578
2579 if (_DBUS_UNLIKELY (len > real->len - start))
2580 return FALSE;
2581
2582 p = real->str + start;
2583 end = p + len;
2584
2585 while (p < end)
2586 {
2587 int i, mask, char_len;
2588 dbus_unichar_t result;
2589
2590 /* nul bytes considered invalid */
2591 if (*p == '\0')
2592 break;
2593
2594 /* Special-case ASCII; this makes us go a lot faster in
2595 * D-Bus profiles where we are typically validating
2596 * function names and such. We have to know that
2597 * all following checks will pass for ASCII though,
2598 * comments follow ...
2599 */
2600 if (*p < 128)
2601 {
2602 ++p;
2603 continue;
2604 }
2605
2606 UTF8_COMPUTE (*p, mask, char_len);
2607
2608 if (_DBUS_UNLIKELY (char_len == 0)) /* ASCII: char_len == 1 */
2609 break;
2610
2611 /* check that the expected number of bytes exists in the remaining length */
2612 if (_DBUS_UNLIKELY ((end - p) < char_len)) /* ASCII: p < end and char_len == 1 */
2613 break;
2614
2615 UTF8_GET (result, p, i, mask, char_len);
2616
2617 /* Check for overlong UTF-8 */
2618 if (_DBUS_UNLIKELY (UTF8_LENGTH (result) != char_len)) /* ASCII: UTF8_LENGTH == 1 */
2619 break;
2620 #if 0
2621 /* The UNICODE_VALID check below will catch this */
2622 if (_DBUS_UNLIKELY (result == (dbus_unichar_t)-1)) /* ASCII: result = ascii value */
2623 break;
2624 #endif
2625
2626 if (_DBUS_UNLIKELY (!UNICODE_VALID (result))) /* ASCII: always valid */
2627 break;
2628
2629 /* UNICODE_VALID should have caught it */
2630 _dbus_assert (result != (dbus_unichar_t)-1);
2631
2632 p += char_len;
2633 }
2634
2635 /* See that we covered the entire length if a length was
2636 * passed in
2637 */
2638 if (_DBUS_UNLIKELY (p != end))
2639 return FALSE;
2640 else
2641 return TRUE;
2642 }
2643
2644 /**
2645 * Checks that the given range of the string is all nul bytes. If the
2646 * given range is not entirely contained in the string, returns
2647 * #FALSE.
2648 *
2649 * @todo this is inconsistent with most of DBusString in that
2650 * it allows a start,len range that extends past the string end.
2651 *
2652 * @param str the string
2653 * @param start first byte index to check
2654 * @param len number of bytes to check
2655 * @returns #TRUE if the byte range exists and is all nul bytes
2656 */
2657 dbus_bool_t
_dbus_string_validate_nul(const DBusString * str,int start,int len)2658 _dbus_string_validate_nul (const DBusString *str,
2659 int start,
2660 int len)
2661 {
2662 const unsigned char *s;
2663 const unsigned char *end;
2664 DBUS_CONST_STRING_PREAMBLE (str);
2665 _dbus_assert (start >= 0);
2666 _dbus_assert (len >= 0);
2667 _dbus_assert (start <= real->len);
2668
2669 if (len > real->len - start)
2670 return FALSE;
2671
2672 s = real->str + start;
2673 end = s + len;
2674 while (s != end)
2675 {
2676 if (_DBUS_UNLIKELY (*s != '\0'))
2677 return FALSE;
2678 ++s;
2679 }
2680
2681 return TRUE;
2682 }
2683
2684 /**
2685 * Clears all allocated bytes in the string to zero.
2686 *
2687 * @param str the string
2688 */
2689 void
_dbus_string_zero(DBusString * str)2690 _dbus_string_zero (DBusString *str)
2691 {
2692 DBUS_STRING_PREAMBLE (str);
2693
2694 memset (real->str - real->align_offset, '\0', real->allocated);
2695 }
2696 /** @} */
2697
2698 /* tests are in dbus-string-util.c */
2699