1 /* -*- mode: C; c-file-style: "gnu" -*- */ 2 /* dbus-string.c String utility class (internal to D-Bus implementation) 3 * 4 * Copyright (C) 2002, 2003, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23 24 #include "dbus-internals.h" 25 #include "dbus-string.h" 26 /* we allow a system header here, for speed/convenience */ 27 #include <string.h> 28 /* for vsnprintf */ 29 #include <stdio.h> 30 #define DBUS_CAN_USE_DBUS_STRING_PRIVATE 1 31 #include "dbus-string-private.h" 32 #include "dbus-marshal-basic.h" /* probably should be removed by moving the usage of DBUS_TYPE 33 * into the marshaling-related files 34 */ 35 /* for DBUS_VA_COPY */ 36 #include "dbus-sysdeps.h" 37 38 /** 39 * @defgroup DBusString DBusString class 40 * @ingroup DBusInternals 41 * @brief DBusString data structure for safer string handling 42 * 43 * Types and functions related to DBusString. DBusString is intended 44 * to be a string class that makes it hard to mess up security issues 45 * (and just in general harder to write buggy code). It should be 46 * used (or extended and then used) rather than the libc stuff in 47 * string.h. The string class is a bit inconvenient at spots because 48 * it handles out-of-memory failures and tries to be extra-robust. 49 * 50 * A DBusString has a maximum length set at initialization time; this 51 * can be used to ensure that a buffer doesn't get too big. The 52 * _dbus_string_lengthen() method checks for overflow, and for max 53 * length being exceeded. 54 * 55 * Try to avoid conversion to a plain C string, i.e. add methods on 56 * the string object instead, only convert to C string when passing 57 * things out to the public API. In particular, no sprintf, strcpy, 58 * strcat, any of that should be used. The GString feature of 59 * accepting negative numbers for "length of string" is also absent, 60 * because it could keep us from detecting bogus huge lengths. i.e. if 61 * we passed in some bogus huge length it would be taken to mean 62 * "current length of string" instead of "broken crack" 63 * 64 * @todo #DBusString needs a lot of cleaning up; some of the 65 * API is no longer used, and the API is pretty inconsistent. 66 * In particular all the "append" APIs, especially those involving 67 * alignment but probably lots of them, are no longer used by the 68 * marshaling code which always does "inserts" now. 69 */ 70 71 /** 72 * @addtogroup DBusString 73 * @{ 74 */ 75 76 static void 77 fixup_alignment (DBusRealString *real) 78 { 79 unsigned char *aligned; 80 unsigned char *real_block; 81 unsigned int old_align_offset; 82 83 /* we have to have extra space in real->allocated for the align offset and nul byte */ 84 _dbus_assert (real->len <= real->allocated - _DBUS_STRING_ALLOCATION_PADDING); 85 86 old_align_offset = real->align_offset; 87 real_block = real->str - old_align_offset; 88 89 aligned = _DBUS_ALIGN_ADDRESS (real_block, 8); 90 91 real->align_offset = aligned - real_block; 92 real->str = aligned; 93 94 if (old_align_offset != real->align_offset) 95 { 96 /* Here comes the suck */ 97 memmove (real_block + real->align_offset, 98 real_block + old_align_offset, 99 real->len + 1); 100 } 101 102 _dbus_assert (real->align_offset < 8); 103 _dbus_assert (_DBUS_ALIGN_ADDRESS (real->str, 8) == real->str); 104 } 105 106 static void 107 undo_alignment (DBusRealString *real) 108 { 109 if (real->align_offset != 0) 110 { 111 memmove (real->str - real->align_offset, 112 real->str, 113 real->len + 1); 114 115 real->str = real->str - real->align_offset; 116 real->align_offset = 0; 117 } 118 } 119 120 /** 121 * Initializes a string that can be up to the given allocation size 122 * before it has to realloc. The string starts life with zero length. 123 * The string must eventually be freed with _dbus_string_free(). 124 * 125 * @param str memory to hold the string 126 * @param allocate_size amount to preallocate 127 * @returns #TRUE on success, #FALSE if no memory 128 */ 129 dbus_bool_t 130 _dbus_string_init_preallocated (DBusString *str, 131 int allocate_size) 132 { 133 DBusRealString *real; 134 135 _dbus_assert (str != NULL); 136 137 _dbus_assert (sizeof (DBusString) == sizeof (DBusRealString)); 138 139 real = (DBusRealString*) str; 140 141 /* It's very important not to touch anything 142 * other than real->str if we're going to fail, 143 * since we also use this function to reset 144 * an existing string, e.g. in _dbus_string_steal_data() 145 */ 146 147 real->str = dbus_malloc (_DBUS_STRING_ALLOCATION_PADDING + allocate_size); 148 if (real->str == NULL) 149 return FALSE; 150 151 real->allocated = _DBUS_STRING_ALLOCATION_PADDING + allocate_size; 152 real->len = 0; 153 real->str[real->len] = '\0'; 154 155 real->max_length = _DBUS_STRING_MAX_MAX_LENGTH; 156 real->constant = FALSE; 157 real->locked = FALSE; 158 real->invalid = FALSE; 159 real->align_offset = 0; 160 161 fixup_alignment (real); 162 163 return TRUE; 164 } 165 166 /** 167 * Initializes a string. The string starts life with zero length. The 168 * string must eventually be freed with _dbus_string_free(). 169 * 170 * @param str memory to hold the string 171 * @returns #TRUE on success, #FALSE if no memory 172 */ 173 dbus_bool_t 174 _dbus_string_init (DBusString *str) 175 { 176 return _dbus_string_init_preallocated (str, 0); 177 } 178 179 #ifdef DBUS_BUILD_TESTS 180 /* The max length thing is sort of a historical artifact 181 * from a feature that turned out to be dumb; perhaps 182 * we should purge it entirely. The problem with 183 * the feature is that it looks like memory allocation 184 * failure, but is not a transient or resolvable failure. 185 */ 186 static void 187 set_max_length (DBusString *str, 188 int max_length) 189 { 190 DBusRealString *real; 191 192 real = (DBusRealString*) str; 193 194 real->max_length = max_length; 195 } 196 #endif /* DBUS_BUILD_TESTS */ 197 198 /** 199 * Initializes a constant string. The value parameter is not copied 200 * (should be static), and the string may never be modified. 201 * It is safe but not necessary to call _dbus_string_free() 202 * on a const string. The string has a length limit of MAXINT - 8. 203 * 204 * @param str memory to use for the string 205 * @param value a string to be stored in str (not copied!!!) 206 */ 207 void 208 _dbus_string_init_const (DBusString *str, 209 const char *value) 210 { 211 _dbus_assert (value != NULL); 212 213 _dbus_string_init_const_len (str, value, 214 strlen (value)); 215 } 216 217 /** 218 * Initializes a constant string with a length. The value parameter is 219 * not copied (should be static), and the string may never be 220 * modified. It is safe but not necessary to call _dbus_string_free() 221 * on a const string. 222 * 223 * @param str memory to use for the string 224 * @param value a string to be stored in str (not copied!!!) 225 * @param len the length to use 226 */ 227 void 228 _dbus_string_init_const_len (DBusString *str, 229 const char *value, 230 int len) 231 { 232 DBusRealString *real; 233 234 _dbus_assert (str != NULL); 235 _dbus_assert (len == 0 || value != NULL); 236 _dbus_assert (len <= _DBUS_STRING_MAX_MAX_LENGTH); 237 _dbus_assert (len >= 0); 238 239 real = (DBusRealString*) str; 240 241 real->str = (unsigned char*) value; 242 real->len = len; 243 real->allocated = real->len + _DBUS_STRING_ALLOCATION_PADDING; /* a lie, just to avoid special-case assertions... */ 244 real->max_length = real->len + 1; 245 real->constant = TRUE; 246 real->locked = TRUE; 247 real->invalid = FALSE; 248 real->align_offset = 0; 249 250 /* We don't require const strings to be 8-byte aligned as the 251 * memory is coming from elsewhere. 252 */ 253 } 254 255 /** 256 * Frees a string created by _dbus_string_init(). 257 * 258 * @param str memory where the string is stored. 259 */ 260 void 261 _dbus_string_free (DBusString *str) 262 { 263 DBusRealString *real = (DBusRealString*) str; 264 DBUS_GENERIC_STRING_PREAMBLE (real); 265 266 if (real->constant) 267 return; 268 dbus_free (real->str - real->align_offset); 269 270 real->invalid = TRUE; 271 } 272 273 #ifdef DBUS_BUILD_TESTS 274 /* Not using this feature at the moment, 275 * so marked DBUS_BUILD_TESTS-only 276 */ 277 /** 278 * Locks a string such that any attempts to change the string will 279 * result in aborting the program. Also, if the string is wasting a 280 * lot of memory (allocation is sufficiently larger than what the 281 * string is really using), _dbus_string_lock() will realloc the 282 * string's data to "compact" it. 283 * 284 * @param str the string to lock. 285 */ 286 void 287 _dbus_string_lock (DBusString *str) 288 { 289 DBUS_LOCKED_STRING_PREAMBLE (str); /* can lock multiple times */ 290 291 real->locked = TRUE; 292 293 /* Try to realloc to avoid excess memory usage, since 294 * we know we won't change the string further 295 */ 296 #define MAX_WASTE 48 297 if (real->allocated - MAX_WASTE > real->len) 298 { 299 unsigned char *new_str; 300 int new_allocated; 301 302 new_allocated = real->len + _DBUS_STRING_ALLOCATION_PADDING; 303 304 new_str = dbus_realloc (real->str - real->align_offset, 305 new_allocated); 306 if (new_str != NULL) 307 { 308 real->str = new_str + real->align_offset; 309 real->allocated = new_allocated; 310 fixup_alignment (real); 311 } 312 } 313 } 314 #endif /* DBUS_BUILD_TESTS */ 315 316 static dbus_bool_t 317 reallocate_for_length (DBusRealString *real, 318 int new_length) 319 { 320 int new_allocated; 321 unsigned char *new_str; 322 323 /* at least double our old allocation to avoid O(n), avoiding 324 * overflow 325 */ 326 if (real->allocated > (_DBUS_STRING_MAX_MAX_LENGTH + _DBUS_STRING_ALLOCATION_PADDING) / 2) 327 new_allocated = _DBUS_STRING_MAX_MAX_LENGTH + _DBUS_STRING_ALLOCATION_PADDING; 328 else 329 new_allocated = real->allocated * 2; 330 331 /* if you change the code just above here, run the tests without 332 * the following assert-only hack before you commit 333 */ 334 /* This is keyed off asserts in addition to tests so when you 335 * disable asserts to profile, you don't get this destroyer 336 * of profiles. 337 */ 338 #ifdef DBUS_DISABLE_ASSERT 339 #else 340 #ifdef DBUS_BUILD_TESTS 341 new_allocated = 0; /* ensure a realloc every time so that we go 342 * through all malloc failure codepaths 343 */ 344 #endif /* DBUS_BUILD_TESTS */ 345 #endif /* !DBUS_DISABLE_ASSERT */ 346 347 /* But be sure we always alloc at least space for the new length */ 348 new_allocated = MAX (new_allocated, 349 new_length + _DBUS_STRING_ALLOCATION_PADDING); 350 351 _dbus_assert (new_allocated >= real->allocated); /* code relies on this */ 352 new_str = dbus_realloc (real->str - real->align_offset, new_allocated); 353 if (_DBUS_UNLIKELY (new_str == NULL)) 354 return FALSE; 355 356 real->str = new_str + real->align_offset; 357 real->allocated = new_allocated; 358 fixup_alignment (real); 359 360 return TRUE; 361 } 362 363 static dbus_bool_t 364 set_length (DBusRealString *real, 365 int new_length) 366 { 367 /* Note, we are setting the length not including nul termination */ 368 369 /* exceeding max length is the same as failure to allocate memory */ 370 if (_DBUS_UNLIKELY (new_length > real->max_length)) 371 return FALSE; 372 else if (new_length > (real->allocated - _DBUS_STRING_ALLOCATION_PADDING) && 373 _DBUS_UNLIKELY (!reallocate_for_length (real, new_length))) 374 return FALSE; 375 else 376 { 377 real->len = new_length; 378 real->str[new_length] = '\0'; 379 return TRUE; 380 } 381 } 382 383 static dbus_bool_t 384 open_gap (int len, 385 DBusRealString *dest, 386 int insert_at) 387 { 388 if (len == 0) 389 return TRUE; 390 391 if (len > dest->max_length - dest->len) 392 return FALSE; /* detected overflow of dest->len + len below */ 393 394 if (!set_length (dest, dest->len + len)) 395 return FALSE; 396 397 memmove (dest->str + insert_at + len, 398 dest->str + insert_at, 399 dest->len - len - insert_at); 400 401 return TRUE; 402 } 403 404 #ifndef _dbus_string_get_data 405 /** 406 * Gets the raw character buffer from the string. The returned buffer 407 * will be nul-terminated, but note that strings may contain binary 408 * data so there may be extra nul characters prior to the termination. 409 * This function should be little-used, extend DBusString or add 410 * stuff to dbus-sysdeps.c instead. It's an error to use this 411 * function on a const string. 412 * 413 * @param str the string 414 * @returns the data 415 */ 416 char* 417 _dbus_string_get_data (DBusString *str) 418 { 419 DBUS_STRING_PREAMBLE (str); 420 421 return (char*) real->str; 422 } 423 #endif /* _dbus_string_get_data */ 424 425 /* only do the function if we don't have the macro */ 426 #ifndef _dbus_string_get_const_data 427 /** 428 * Gets the raw character buffer from a const string. 429 * 430 * @param str the string 431 * @returns the string data 432 */ 433 const char* 434 _dbus_string_get_const_data (const DBusString *str) 435 { 436 DBUS_CONST_STRING_PREAMBLE (str); 437 438 return (const char*) real->str; 439 } 440 #endif /* _dbus_string_get_const_data */ 441 442 /** 443 * Gets a sub-portion of the raw character buffer from the 444 * string. The "len" field is required simply for error 445 * checking, to be sure you don't try to use more 446 * string than exists. The nul termination of the 447 * returned buffer remains at the end of the entire 448 * string, not at start + len. 449 * 450 * @param str the string 451 * @param start byte offset to return 452 * @param len length of segment to return 453 * @returns the string data 454 */ 455 char* 456 _dbus_string_get_data_len (DBusString *str, 457 int start, 458 int len) 459 { 460 DBUS_STRING_PREAMBLE (str); 461 _dbus_assert (start >= 0); 462 _dbus_assert (len >= 0); 463 _dbus_assert (start <= real->len); 464 _dbus_assert (len <= real->len - start); 465 466 return (char*) real->str + start; 467 } 468 469 /* only do the function if we don't have the macro */ 470 #ifndef _dbus_string_get_const_data_len 471 /** 472 * const version of _dbus_string_get_data_len(). 473 * 474 * @param str the string 475 * @param start byte offset to return 476 * @param len length of segment to return 477 * @returns the string data 478 */ 479 const char* 480 _dbus_string_get_const_data_len (const DBusString *str, 481 int start, 482 int len) 483 { 484 DBUS_CONST_STRING_PREAMBLE (str); 485 _dbus_assert (start >= 0); 486 _dbus_assert (len >= 0); 487 _dbus_assert (start <= real->len); 488 _dbus_assert (len <= real->len - start); 489 490 return (const char*) real->str + start; 491 } 492 #endif /* _dbus_string_get_const_data_len */ 493 494 /* only do the function if we don't have the macro */ 495 #ifndef _dbus_string_set_byte 496 /** 497 * Sets the value of the byte at the given position. 498 * 499 * @param str the string 500 * @param i the position 501 * @param byte the new value 502 */ 503 void 504 _dbus_string_set_byte (DBusString *str, 505 int i, 506 unsigned char byte) 507 { 508 DBUS_STRING_PREAMBLE (str); 509 _dbus_assert (i < real->len); 510 _dbus_assert (i >= 0); 511 512 real->str[i] = byte; 513 } 514 #endif /* _dbus_string_set_byte */ 515 516 /* only have the function if we didn't create a macro */ 517 #ifndef _dbus_string_get_byte 518 /** 519 * Gets the byte at the given position. It is 520 * allowed to ask for the nul byte at the end of 521 * the string. 522 * 523 * @param str the string 524 * @param start the position 525 * @returns the byte at that position 526 */ 527 unsigned char 528 _dbus_string_get_byte (const DBusString *str, 529 int start) 530 { 531 DBUS_CONST_STRING_PREAMBLE (str); 532 _dbus_assert (start <= real->len); 533 _dbus_assert (start >= 0); 534 535 return real->str[start]; 536 } 537 #endif /* _dbus_string_get_byte */ 538 539 /** 540 * Inserts a number of bytes of a given value at the 541 * given position. 542 * 543 * @param str the string 544 * @param i the position 545 * @param n_bytes number of bytes 546 * @param byte the value to insert 547 * @returns #TRUE on success 548 */ 549 dbus_bool_t 550 _dbus_string_insert_bytes (DBusString *str, 551 int i, 552 int n_bytes, 553 unsigned char byte) 554 { 555 DBUS_STRING_PREAMBLE (str); 556 _dbus_assert (i <= real->len); 557 _dbus_assert (i >= 0); 558 _dbus_assert (n_bytes >= 0); 559 560 if (n_bytes == 0) 561 return TRUE; 562 563 if (!open_gap (n_bytes, real, i)) 564 return FALSE; 565 566 memset (real->str + i, byte, n_bytes); 567 568 return TRUE; 569 } 570 571 /** 572 * Inserts a single byte at the given position. 573 * 574 * @param str the string 575 * @param i the position 576 * @param byte the value to insert 577 * @returns #TRUE on success 578 */ 579 dbus_bool_t 580 _dbus_string_insert_byte (DBusString *str, 581 int i, 582 unsigned char byte) 583 { 584 DBUS_STRING_PREAMBLE (str); 585 _dbus_assert (i <= real->len); 586 _dbus_assert (i >= 0); 587 588 if (!open_gap (1, real, i)) 589 return FALSE; 590 591 real->str[i] = byte; 592 593 return TRUE; 594 } 595 596 /** 597 * Like _dbus_string_get_data(), but removes the 598 * gotten data from the original string. The caller 599 * must free the data returned. This function may 600 * fail due to lack of memory, and return #FALSE. 601 * 602 * @param str the string 603 * @param data_return location to return the buffer 604 * @returns #TRUE on success 605 */ 606 dbus_bool_t 607 _dbus_string_steal_data (DBusString *str, 608 char **data_return) 609 { 610 int old_max_length; 611 DBUS_STRING_PREAMBLE (str); 612 _dbus_assert (data_return != NULL); 613 614 undo_alignment (real); 615 616 *data_return = (char*) real->str; 617 618 old_max_length = real->max_length; 619 620 /* reset the string */ 621 if (!_dbus_string_init (str)) 622 { 623 /* hrm, put it back then */ 624 real->str = (unsigned char*) *data_return; 625 *data_return = NULL; 626 fixup_alignment (real); 627 return FALSE; 628 } 629 630 real->max_length = old_max_length; 631 632 return TRUE; 633 } 634 635 #ifdef DBUS_BUILD_TESTS 636 /** 637 * Like _dbus_string_get_data_len(), but removes the gotten data from 638 * the original string. The caller must free the data returned. This 639 * function may fail due to lack of memory, and return #FALSE. 640 * The returned string is nul-terminated and has length len. 641 * 642 * @todo this function is broken because on failure it 643 * may corrupt the source string. 644 * 645 * @param str the string 646 * @param data_return location to return the buffer 647 * @param start the start of segment to steal 648 * @param len the length of segment to steal 649 * @returns #TRUE on success 650 */ 651 dbus_bool_t 652 _dbus_string_steal_data_len (DBusString *str, 653 char **data_return, 654 int start, 655 int len) 656 { 657 DBusString dest; 658 DBUS_STRING_PREAMBLE (str); 659 _dbus_assert (data_return != NULL); 660 _dbus_assert (start >= 0); 661 _dbus_assert (len >= 0); 662 _dbus_assert (start <= real->len); 663 _dbus_assert (len <= real->len - start); 664 665 if (!_dbus_string_init (&dest)) 666 return FALSE; 667 668 set_max_length (&dest, real->max_length); 669 670 if (!_dbus_string_move_len (str, start, len, &dest, 0)) 671 { 672 _dbus_string_free (&dest); 673 return FALSE; 674 } 675 676 _dbus_warn ("Broken code in _dbus_string_steal_data_len(), see @todo, FIXME\n"); 677 if (!_dbus_string_steal_data (&dest, data_return)) 678 { 679 _dbus_string_free (&dest); 680 return FALSE; 681 } 682 683 _dbus_string_free (&dest); 684 return TRUE; 685 } 686 #endif /* DBUS_BUILD_TESTS */ 687 688 /** 689 * Copies the data from the string into a char* 690 * 691 * @param str the string 692 * @param data_return place to return the data 693 * @returns #TRUE on success, #FALSE on no memory 694 */ 695 dbus_bool_t 696 _dbus_string_copy_data (const DBusString *str, 697 char **data_return) 698 { 699 DBUS_CONST_STRING_PREAMBLE (str); 700 _dbus_assert (data_return != NULL); 701 702 *data_return = dbus_malloc (real->len + 1); 703 if (*data_return == NULL) 704 return FALSE; 705 706 memcpy (*data_return, real->str, real->len + 1); 707 708 return TRUE; 709 } 710 711 /** 712 * Copies the contents of a DBusString into a different 713 * buffer. The resulting buffer will be nul-terminated. 714 * 715 * @param str a string 716 * @param buffer a C buffer to copy data to 717 * @param avail_len maximum length of C buffer 718 */ 719 void 720 _dbus_string_copy_to_buffer (const DBusString *str, 721 char *buffer, 722 int avail_len) 723 { 724 int copy_len; 725 DBUS_CONST_STRING_PREAMBLE (str); 726 727 _dbus_assert (avail_len >= 0); 728 729 copy_len = MIN (avail_len, real->len+1); 730 memcpy (buffer, real->str, copy_len); 731 if (avail_len > 0 && avail_len == copy_len) 732 buffer[avail_len-1] = '\0'; 733 } 734 735 #ifdef DBUS_BUILD_TESTS 736 /** 737 * Copies a segment of the string into a char* 738 * 739 * @param str the string 740 * @param data_return place to return the data 741 * @param start start index 742 * @param len length to copy 743 * @returns #FALSE if no memory 744 */ 745 dbus_bool_t 746 _dbus_string_copy_data_len (const DBusString *str, 747 char **data_return, 748 int start, 749 int len) 750 { 751 DBusString dest; 752 753 DBUS_CONST_STRING_PREAMBLE (str); 754 _dbus_assert (data_return != NULL); 755 _dbus_assert (start >= 0); 756 _dbus_assert (len >= 0); 757 _dbus_assert (start <= real->len); 758 _dbus_assert (len <= real->len - start); 759 760 if (!_dbus_string_init (&dest)) 761 return FALSE; 762 763 set_max_length (&dest, real->max_length); 764 765 if (!_dbus_string_copy_len (str, start, len, &dest, 0)) 766 { 767 _dbus_string_free (&dest); 768 return FALSE; 769 } 770 771 if (!_dbus_string_steal_data (&dest, data_return)) 772 { 773 _dbus_string_free (&dest); 774 return FALSE; 775 } 776 777 _dbus_string_free (&dest); 778 return TRUE; 779 } 780 #endif /* DBUS_BUILD_TESTS */ 781 782 /* Only have the function if we don't have the macro */ 783 #ifndef _dbus_string_get_length 784 /** 785 * Gets the length of a string (not including nul termination). 786 * 787 * @returns the length. 788 */ 789 int 790 _dbus_string_get_length (const DBusString *str) 791 { 792 /* The assertion should not fail for empty strings. */ 793 DBusRealString *real = (DBusRealString *)str; 794 if (((DBusRealString *)str)->len || ((DBusRealString *)str)->allocated) { 795 DBUS_CONST_STRING_PREAMBLE (str); 796 } 797 798 return real->len; 799 } 800 #endif /* !_dbus_string_get_length */ 801 802 /** 803 * Makes a string longer by the given number of bytes. Checks whether 804 * adding additional_length to the current length would overflow an 805 * integer, and checks for exceeding a string's max length. 806 * The new bytes are not initialized, other than nul-terminating 807 * the end of the string. The uninitialized bytes may contain 808 * nul bytes or other junk. 809 * 810 * @param str a string 811 * @param additional_length length to add to the string. 812 * @returns #TRUE on success. 813 */ 814 dbus_bool_t 815 _dbus_string_lengthen (DBusString *str, 816 int additional_length) 817 { 818 DBUS_STRING_PREAMBLE (str); 819 _dbus_assert (additional_length >= 0); 820 821 if (_DBUS_UNLIKELY (additional_length > real->max_length - real->len)) 822 return FALSE; /* would overflow */ 823 824 return set_length (real, 825 real->len + additional_length); 826 } 827 828 /** 829 * Makes a string shorter by the given number of bytes. 830 * 831 * @param str a string 832 * @param length_to_remove length to remove from the string. 833 */ 834 void 835 _dbus_string_shorten (DBusString *str, 836 int length_to_remove) 837 { 838 DBUS_STRING_PREAMBLE (str); 839 _dbus_assert (length_to_remove >= 0); 840 _dbus_assert (length_to_remove <= real->len); 841 842 set_length (real, 843 real->len - length_to_remove); 844 } 845 846 /** 847 * Sets the length of a string. Can be used to truncate or lengthen 848 * the string. If the string is lengthened, the function may fail and 849 * return #FALSE. Newly-added bytes are not initialized, as with 850 * _dbus_string_lengthen(). 851 * 852 * @param str a string 853 * @param length new length of the string. 854 * @returns #FALSE on failure. 855 */ 856 dbus_bool_t 857 _dbus_string_set_length (DBusString *str, 858 int length) 859 { 860 DBUS_STRING_PREAMBLE (str); 861 _dbus_assert (length >= 0); 862 863 return set_length (real, length); 864 } 865 866 static dbus_bool_t 867 align_insert_point_then_open_gap (DBusString *str, 868 int *insert_at_p, 869 int alignment, 870 int gap_size) 871 { 872 unsigned long new_len; /* ulong to avoid _DBUS_ALIGN_VALUE overflow */ 873 unsigned long gap_pos; 874 int insert_at; 875 int delta; 876 DBUS_STRING_PREAMBLE (str); 877 _dbus_assert (alignment >= 1); 878 _dbus_assert (alignment <= 8); /* it has to be a bug if > 8 */ 879 880 insert_at = *insert_at_p; 881 882 _dbus_assert (insert_at <= real->len); 883 884 gap_pos = _DBUS_ALIGN_VALUE (insert_at, alignment); 885 new_len = real->len + (gap_pos - insert_at) + gap_size; 886 887 if (_DBUS_UNLIKELY (new_len > (unsigned long) real->max_length)) 888 return FALSE; 889 890 delta = new_len - real->len; 891 _dbus_assert (delta >= 0); 892 893 if (delta == 0) /* only happens if gap_size == 0 and insert_at is aligned already */ 894 { 895 _dbus_assert (((unsigned long) *insert_at_p) == gap_pos); 896 return TRUE; 897 } 898 899 if (_DBUS_UNLIKELY (!open_gap (new_len - real->len, 900 real, insert_at))) 901 return FALSE; 902 903 /* nul the padding if we had to add any padding */ 904 if (gap_size < delta) 905 { 906 memset (&real->str[insert_at], '\0', 907 gap_pos - insert_at); 908 } 909 910 *insert_at_p = gap_pos; 911 912 return TRUE; 913 } 914 915 static dbus_bool_t 916 align_length_then_lengthen (DBusString *str, 917 int alignment, 918 int then_lengthen_by) 919 { 920 int insert_at; 921 922 insert_at = _dbus_string_get_length (str); 923 924 return align_insert_point_then_open_gap (str, 925 &insert_at, 926 alignment, then_lengthen_by); 927 } 928 929 /** 930 * Align the length of a string to a specific alignment (typically 4 or 8) 931 * by appending nul bytes to the string. 932 * 933 * @param str a string 934 * @param alignment the alignment 935 * @returns #FALSE if no memory 936 */ 937 dbus_bool_t 938 _dbus_string_align_length (DBusString *str, 939 int alignment) 940 { 941 return align_length_then_lengthen (str, alignment, 0); 942 } 943 944 /** 945 * Preallocate extra_bytes such that a future lengthening of the 946 * string by extra_bytes is guaranteed to succeed without an out of 947 * memory error. 948 * 949 * @param str a string 950 * @param extra_bytes bytes to alloc 951 * @returns #FALSE if no memory 952 */ 953 dbus_bool_t 954 _dbus_string_alloc_space (DBusString *str, 955 int extra_bytes) 956 { 957 if (!_dbus_string_lengthen (str, extra_bytes)) 958 return FALSE; 959 _dbus_string_shorten (str, extra_bytes); 960 961 return TRUE; 962 } 963 964 static dbus_bool_t 965 append (DBusRealString *real, 966 const char *buffer, 967 int buffer_len) 968 { 969 if (buffer_len == 0) 970 return TRUE; 971 972 if (!_dbus_string_lengthen ((DBusString*)real, buffer_len)) 973 return FALSE; 974 975 memcpy (real->str + (real->len - buffer_len), 976 buffer, 977 buffer_len); 978 979 return TRUE; 980 } 981 982 /** 983 * Appends a nul-terminated C-style string to a DBusString. 984 * 985 * @param str the DBusString 986 * @param buffer the nul-terminated characters to append 987 * @returns #FALSE if not enough memory. 988 */ 989 dbus_bool_t 990 _dbus_string_append (DBusString *str, 991 const char *buffer) 992 { 993 unsigned long buffer_len; 994 995 DBUS_STRING_PREAMBLE (str); 996 _dbus_assert (buffer != NULL); 997 998 buffer_len = strlen (buffer); 999 if (buffer_len > (unsigned long) real->max_length) 1000 return FALSE; 1001 1002 return append (real, buffer, buffer_len); 1003 } 1004 1005 /** assign 2 bytes from one string to another */ 1006 #define ASSIGN_2_OCTETS(p, octets) \ 1007 *((dbus_uint16_t*)(p)) = *((dbus_uint16_t*)(octets)); 1008 1009 /** assign 4 bytes from one string to another */ 1010 #define ASSIGN_4_OCTETS(p, octets) \ 1011 *((dbus_uint32_t*)(p)) = *((dbus_uint32_t*)(octets)); 1012 1013 #ifdef DBUS_HAVE_INT64 1014 /** assign 8 bytes from one string to another */ 1015 #define ASSIGN_8_OCTETS(p, octets) \ 1016 *((dbus_uint64_t*)(p)) = *((dbus_uint64_t*)(octets)); 1017 #else 1018 /** assign 8 bytes from one string to another */ 1019 #define ASSIGN_8_OCTETS(p, octets) \ 1020 do { \ 1021 unsigned char *b; \ 1022 \ 1023 b = p; \ 1024 \ 1025 *b++ = octets[0]; \ 1026 *b++ = octets[1]; \ 1027 *b++ = octets[2]; \ 1028 *b++ = octets[3]; \ 1029 *b++ = octets[4]; \ 1030 *b++ = octets[5]; \ 1031 *b++ = octets[6]; \ 1032 *b++ = octets[7]; \ 1033 _dbus_assert (b == p + 8); \ 1034 } while (0) 1035 #endif /* DBUS_HAVE_INT64 */ 1036 1037 #ifdef DBUS_BUILD_TESTS 1038 /** 1039 * Appends 4 bytes aligned on a 4 byte boundary 1040 * with any alignment padding initialized to 0. 1041 * 1042 * @param str the DBusString 1043 * @param octets 4 bytes to append 1044 * @returns #FALSE if not enough memory. 1045 */ 1046 dbus_bool_t 1047 _dbus_string_append_4_aligned (DBusString *str, 1048 const unsigned char octets[4]) 1049 { 1050 DBUS_STRING_PREAMBLE (str); 1051 1052 if (!align_length_then_lengthen (str, 4, 4)) 1053 return FALSE; 1054 1055 ASSIGN_4_OCTETS (real->str + (real->len - 4), octets); 1056 1057 return TRUE; 1058 } 1059 #endif /* DBUS_BUILD_TESTS */ 1060 1061 #ifdef DBUS_BUILD_TESTS 1062 /** 1063 * Appends 8 bytes aligned on an 8 byte boundary 1064 * with any alignment padding initialized to 0. 1065 * 1066 * @param str the DBusString 1067 * @param octets 8 bytes to append 1068 * @returns #FALSE if not enough memory. 1069 */ 1070 dbus_bool_t 1071 _dbus_string_append_8_aligned (DBusString *str, 1072 const unsigned char octets[8]) 1073 { 1074 DBUS_STRING_PREAMBLE (str); 1075 1076 if (!align_length_then_lengthen (str, 8, 8)) 1077 return FALSE; 1078 1079 ASSIGN_8_OCTETS (real->str + (real->len - 8), octets); 1080 1081 return TRUE; 1082 } 1083 #endif /* DBUS_BUILD_TESTS */ 1084 1085 /** 1086 * Inserts 2 bytes aligned on a 2 byte boundary 1087 * with any alignment padding initialized to 0. 1088 * 1089 * @param str the DBusString 1090 * @param insert_at where to insert 1091 * @param octets 2 bytes to insert 1092 * @returns #FALSE if not enough memory. 1093 */ 1094 dbus_bool_t 1095 _dbus_string_insert_2_aligned (DBusString *str, 1096 int insert_at, 1097 const unsigned char octets[4]) 1098 { 1099 DBUS_STRING_PREAMBLE (str); 1100 1101 if (!align_insert_point_then_open_gap (str, &insert_at, 2, 2)) 1102 return FALSE; 1103 1104 ASSIGN_2_OCTETS (real->str + insert_at, octets); 1105 1106 return TRUE; 1107 } 1108 1109 /** 1110 * Inserts 4 bytes aligned on a 4 byte boundary 1111 * with any alignment padding initialized to 0. 1112 * 1113 * @param str the DBusString 1114 * @param insert_at where to insert 1115 * @param octets 4 bytes to insert 1116 * @returns #FALSE if not enough memory. 1117 */ 1118 dbus_bool_t 1119 _dbus_string_insert_4_aligned (DBusString *str, 1120 int insert_at, 1121 const unsigned char octets[4]) 1122 { 1123 DBUS_STRING_PREAMBLE (str); 1124 1125 if (!align_insert_point_then_open_gap (str, &insert_at, 4, 4)) 1126 return FALSE; 1127 1128 ASSIGN_4_OCTETS (real->str + insert_at, octets); 1129 1130 return TRUE; 1131 } 1132 1133 /** 1134 * Inserts 8 bytes aligned on an 8 byte boundary 1135 * with any alignment padding initialized to 0. 1136 * 1137 * @param str the DBusString 1138 * @param insert_at where to insert 1139 * @param octets 8 bytes to insert 1140 * @returns #FALSE if not enough memory. 1141 */ 1142 dbus_bool_t 1143 _dbus_string_insert_8_aligned (DBusString *str, 1144 int insert_at, 1145 const unsigned char octets[8]) 1146 { 1147 DBUS_STRING_PREAMBLE (str); 1148 1149 if (!align_insert_point_then_open_gap (str, &insert_at, 8, 8)) 1150 return FALSE; 1151 1152 _dbus_assert (_DBUS_ALIGN_VALUE (insert_at, 8) == (unsigned) insert_at); 1153 1154 ASSIGN_8_OCTETS (real->str + insert_at, octets); 1155 1156 return TRUE; 1157 } 1158 1159 1160 /** 1161 * Inserts padding at *insert_at such to align it to the given 1162 * boundary. Initializes the padding to nul bytes. Sets *insert_at 1163 * to the aligned position. 1164 * 1165 * @param str the DBusString 1166 * @param insert_at location to be aligned 1167 * @param alignment alignment boundary (1, 2, 4, or 8) 1168 * @returns #FALSE if not enough memory. 1169 */ 1170 dbus_bool_t 1171 _dbus_string_insert_alignment (DBusString *str, 1172 int *insert_at, 1173 int alignment) 1174 { 1175 DBUS_STRING_PREAMBLE (str); 1176 1177 if (!align_insert_point_then_open_gap (str, insert_at, alignment, 0)) 1178 return FALSE; 1179 1180 _dbus_assert (_DBUS_ALIGN_VALUE (*insert_at, alignment) == (unsigned) *insert_at); 1181 1182 return TRUE; 1183 } 1184 1185 /** 1186 * Appends a printf-style formatted string 1187 * to the #DBusString. 1188 * 1189 * @param str the string 1190 * @param format printf format 1191 * @param args variable argument list 1192 * @returns #FALSE if no memory 1193 */ 1194 dbus_bool_t 1195 _dbus_string_append_printf_valist (DBusString *str, 1196 const char *format, 1197 va_list args) 1198 { 1199 int len; 1200 va_list args_copy; 1201 1202 DBUS_STRING_PREAMBLE (str); 1203 1204 DBUS_VA_COPY (args_copy, args); 1205 1206 /* Measure the message length without terminating nul */ 1207 len = _dbus_printf_string_upper_bound (format, args); 1208 1209 if (!_dbus_string_lengthen (str, len)) 1210 { 1211 /* don't leak the copy */ 1212 va_end (args_copy); 1213 return FALSE; 1214 } 1215 1216 vsprintf ((char*) (real->str + (real->len - len)), 1217 format, args_copy); 1218 1219 va_end (args_copy); 1220 1221 return TRUE; 1222 } 1223 1224 /** 1225 * Appends a printf-style formatted string 1226 * to the #DBusString. 1227 * 1228 * @param str the string 1229 * @param format printf format 1230 * @returns #FALSE if no memory 1231 */ 1232 dbus_bool_t 1233 _dbus_string_append_printf (DBusString *str, 1234 const char *format, 1235 ...) 1236 { 1237 va_list args; 1238 dbus_bool_t retval; 1239 1240 va_start (args, format); 1241 retval = _dbus_string_append_printf_valist (str, format, args); 1242 va_end (args); 1243 1244 return retval; 1245 } 1246 1247 /** 1248 * Appends block of bytes with the given length to a DBusString. 1249 * 1250 * @param str the DBusString 1251 * @param buffer the bytes to append 1252 * @param len the number of bytes to append 1253 * @returns #FALSE if not enough memory. 1254 */ 1255 dbus_bool_t 1256 _dbus_string_append_len (DBusString *str, 1257 const char *buffer, 1258 int len) 1259 { 1260 DBUS_STRING_PREAMBLE (str); 1261 _dbus_assert (buffer != NULL); 1262 _dbus_assert (len >= 0); 1263 1264 return append (real, buffer, len); 1265 } 1266 1267 /** 1268 * Appends a single byte to the string, returning #FALSE 1269 * if not enough memory. 1270 * 1271 * @param str the string 1272 * @param byte the byte to append 1273 * @returns #TRUE on success 1274 */ 1275 dbus_bool_t 1276 _dbus_string_append_byte (DBusString *str, 1277 unsigned char byte) 1278 { 1279 DBUS_STRING_PREAMBLE (str); 1280 1281 if (!set_length (real, real->len + 1)) 1282 return FALSE; 1283 1284 real->str[real->len-1] = byte; 1285 1286 return TRUE; 1287 } 1288 1289 #ifdef DBUS_BUILD_TESTS 1290 /** 1291 * Appends a single Unicode character, encoding the character 1292 * in UTF-8 format. 1293 * 1294 * @param str the string 1295 * @param ch the Unicode character 1296 */ 1297 dbus_bool_t 1298 _dbus_string_append_unichar (DBusString *str, 1299 dbus_unichar_t ch) 1300 { 1301 int len; 1302 int first; 1303 int i; 1304 unsigned char *out; 1305 1306 DBUS_STRING_PREAMBLE (str); 1307 1308 /* this code is from GLib but is pretty standard I think */ 1309 1310 len = 0; 1311 1312 if (ch < 0x80) 1313 { 1314 first = 0; 1315 len = 1; 1316 } 1317 else if (ch < 0x800) 1318 { 1319 first = 0xc0; 1320 len = 2; 1321 } 1322 else if (ch < 0x10000) 1323 { 1324 first = 0xe0; 1325 len = 3; 1326 } 1327 else if (ch < 0x200000) 1328 { 1329 first = 0xf0; 1330 len = 4; 1331 } 1332 else if (ch < 0x4000000) 1333 { 1334 first = 0xf8; 1335 len = 5; 1336 } 1337 else 1338 { 1339 first = 0xfc; 1340 len = 6; 1341 } 1342 1343 if (len > (real->max_length - real->len)) 1344 return FALSE; /* real->len + len would overflow */ 1345 1346 if (!set_length (real, real->len + len)) 1347 return FALSE; 1348 1349 out = real->str + (real->len - len); 1350 1351 for (i = len - 1; i > 0; --i) 1352 { 1353 out[i] = (ch & 0x3f) | 0x80; 1354 ch >>= 6; 1355 } 1356 out[0] = ch | first; 1357 1358 return TRUE; 1359 } 1360 #endif /* DBUS_BUILD_TESTS */ 1361 1362 static void 1363 delete (DBusRealString *real, 1364 int start, 1365 int len) 1366 { 1367 if (len == 0) 1368 return; 1369 1370 memmove (real->str + start, real->str + start + len, real->len - (start + len)); 1371 real->len -= len; 1372 real->str[real->len] = '\0'; 1373 } 1374 1375 /** 1376 * Deletes a segment of a DBusString with length len starting at 1377 * start. (Hint: to clear an entire string, setting length to 0 1378 * with _dbus_string_set_length() is easier.) 1379 * 1380 * @param str the DBusString 1381 * @param start where to start deleting 1382 * @param len the number of bytes to delete 1383 */ 1384 void 1385 _dbus_string_delete (DBusString *str, 1386 int start, 1387 int len) 1388 { 1389 DBUS_STRING_PREAMBLE (str); 1390 _dbus_assert (start >= 0); 1391 _dbus_assert (len >= 0); 1392 _dbus_assert (start <= real->len); 1393 _dbus_assert (len <= real->len - start); 1394 1395 delete (real, start, len); 1396 } 1397 1398 static dbus_bool_t 1399 copy (DBusRealString *source, 1400 int start, 1401 int len, 1402 DBusRealString *dest, 1403 int insert_at) 1404 { 1405 if (len == 0) 1406 return TRUE; 1407 1408 if (!open_gap (len, dest, insert_at)) 1409 return FALSE; 1410 1411 memmove (dest->str + insert_at, 1412 source->str + start, 1413 len); 1414 1415 return TRUE; 1416 } 1417 1418 /** 1419 * Checks assertions for two strings we're copying a segment between, 1420 * and declares real_source/real_dest variables. 1421 * 1422 * @param source the source string 1423 * @param start the starting offset 1424 * @param dest the dest string 1425 * @param insert_at where the copied segment is inserted 1426 */ 1427 #define DBUS_STRING_COPY_PREAMBLE(source, start, dest, insert_at) \ 1428 DBusRealString *real_source = (DBusRealString*) source; \ 1429 DBusRealString *real_dest = (DBusRealString*) dest; \ 1430 _dbus_assert ((source) != (dest)); \ 1431 DBUS_GENERIC_STRING_PREAMBLE (real_source); \ 1432 DBUS_GENERIC_STRING_PREAMBLE (real_dest); \ 1433 _dbus_assert (!real_dest->constant); \ 1434 _dbus_assert (!real_dest->locked); \ 1435 _dbus_assert ((start) >= 0); \ 1436 _dbus_assert ((start) <= real_source->len); \ 1437 _dbus_assert ((insert_at) >= 0); \ 1438 _dbus_assert ((insert_at) <= real_dest->len) 1439 1440 /** 1441 * Moves the end of one string into another string. Both strings 1442 * must be initialized, valid strings. 1443 * 1444 * @param source the source string 1445 * @param start where to chop off the source string 1446 * @param dest the destination string 1447 * @param insert_at where to move the chopped-off part of source string 1448 * @returns #FALSE if not enough memory 1449 */ 1450 dbus_bool_t 1451 _dbus_string_move (DBusString *source, 1452 int start, 1453 DBusString *dest, 1454 int insert_at) 1455 { 1456 DBusRealString *real_source = (DBusRealString*) source; 1457 _dbus_assert (start <= real_source->len); 1458 1459 return _dbus_string_move_len (source, start, 1460 real_source->len - start, 1461 dest, insert_at); 1462 } 1463 1464 /** 1465 * Like _dbus_string_move(), but does not delete the section 1466 * of the source string that's copied to the dest string. 1467 * 1468 * @param source the source string 1469 * @param start where to start copying the source string 1470 * @param dest the destination string 1471 * @param insert_at where to place the copied part of source string 1472 * @returns #FALSE if not enough memory 1473 */ 1474 dbus_bool_t 1475 _dbus_string_copy (const DBusString *source, 1476 int start, 1477 DBusString *dest, 1478 int insert_at) 1479 { 1480 DBUS_STRING_COPY_PREAMBLE (source, start, dest, insert_at); 1481 1482 return copy (real_source, start, 1483 real_source->len - start, 1484 real_dest, 1485 insert_at); 1486 } 1487 1488 /** 1489 * Like _dbus_string_move(), but can move a segment from 1490 * the middle of the source string. 1491 * 1492 * @todo this doesn't do anything with max_length field. 1493 * we should probably just kill the max_length field though. 1494 * 1495 * @param source the source string 1496 * @param start first byte of source string to move 1497 * @param len length of segment to move 1498 * @param dest the destination string 1499 * @param insert_at where to move the bytes from the source string 1500 * @returns #FALSE if not enough memory 1501 */ 1502 dbus_bool_t 1503 _dbus_string_move_len (DBusString *source, 1504 int start, 1505 int len, 1506 DBusString *dest, 1507 int insert_at) 1508 1509 { 1510 DBUS_STRING_COPY_PREAMBLE (source, start, dest, insert_at); 1511 _dbus_assert (len >= 0); 1512 _dbus_assert ((start + len) <= real_source->len); 1513 1514 1515 if (len == 0) 1516 { 1517 return TRUE; 1518 } 1519 else if (start == 0 && 1520 len == real_source->len && 1521 real_dest->len == 0) 1522 { 1523 /* Short-circuit moving an entire existing string to an empty string 1524 * by just swapping the buffers. 1525 */ 1526 /* we assume ->constant doesn't matter as you can't have 1527 * a constant string involved in a move. 1528 */ 1529 #define ASSIGN_DATA(a, b) do { \ 1530 (a)->str = (b)->str; \ 1531 (a)->len = (b)->len; \ 1532 (a)->allocated = (b)->allocated; \ 1533 (a)->align_offset = (b)->align_offset; \ 1534 } while (0) 1535 1536 DBusRealString tmp; 1537 1538 ASSIGN_DATA (&tmp, real_source); 1539 ASSIGN_DATA (real_source, real_dest); 1540 ASSIGN_DATA (real_dest, &tmp); 1541 1542 return TRUE; 1543 } 1544 else 1545 { 1546 if (!copy (real_source, start, len, 1547 real_dest, 1548 insert_at)) 1549 return FALSE; 1550 1551 delete (real_source, start, 1552 len); 1553 1554 return TRUE; 1555 } 1556 } 1557 1558 /** 1559 * Like _dbus_string_copy(), but can copy a segment from the middle of 1560 * the source string. 1561 * 1562 * @param source the source string 1563 * @param start where to start copying the source string 1564 * @param len length of segment to copy 1565 * @param dest the destination string 1566 * @param insert_at where to place the copied segment of source string 1567 * @returns #FALSE if not enough memory 1568 */ 1569 dbus_bool_t 1570 _dbus_string_copy_len (const DBusString *source, 1571 int start, 1572 int len, 1573 DBusString *dest, 1574 int insert_at) 1575 { 1576 DBUS_STRING_COPY_PREAMBLE (source, start, dest, insert_at); 1577 _dbus_assert (len >= 0); 1578 _dbus_assert (start <= real_source->len); 1579 _dbus_assert (len <= real_source->len - start); 1580 1581 return copy (real_source, start, len, 1582 real_dest, 1583 insert_at); 1584 } 1585 1586 /** 1587 * Replaces a segment of dest string with a segment of source string. 1588 * 1589 * @todo optimize the case where the two lengths are the same, and 1590 * avoid memmoving the data in the trailing part of the string twice. 1591 * 1592 * @todo avoid inserting the source into dest, then deleting 1593 * the replaced chunk of dest (which creates a potentially large 1594 * intermediate string). Instead, extend the replaced chunk 1595 * of dest with padding to the same size as the source chunk, 1596 * then copy in the source bytes. 1597 * 1598 * @param source the source string 1599 * @param start where to start copying the source string 1600 * @param len length of segment to copy 1601 * @param dest the destination string 1602 * @param replace_at start of segment of dest string to replace 1603 * @param replace_len length of segment of dest string to replace 1604 * @returns #FALSE if not enough memory 1605 * 1606 */ 1607 dbus_bool_t 1608 _dbus_string_replace_len (const DBusString *source, 1609 int start, 1610 int len, 1611 DBusString *dest, 1612 int replace_at, 1613 int replace_len) 1614 { 1615 DBUS_STRING_COPY_PREAMBLE (source, start, dest, replace_at); 1616 _dbus_assert (len >= 0); 1617 _dbus_assert (start <= real_source->len); 1618 _dbus_assert (len <= real_source->len - start); 1619 _dbus_assert (replace_at >= 0); 1620 _dbus_assert (replace_at <= real_dest->len); 1621 _dbus_assert (replace_len <= real_dest->len - replace_at); 1622 1623 if (!copy (real_source, start, len, 1624 real_dest, replace_at)) 1625 return FALSE; 1626 1627 delete (real_dest, replace_at + len, replace_len); 1628 1629 return TRUE; 1630 } 1631 1632 /* Unicode macros and utf8_validate() from GLib Owen Taylor, Havoc 1633 * Pennington, and Tom Tromey are the authors and authorized relicense. 1634 */ 1635 1636 /** computes length and mask of a unicode character 1637 * @param Char the char 1638 * @param Mask the mask variable to assign to 1639 * @param Len the length variable to assign to 1640 */ 1641 #define UTF8_COMPUTE(Char, Mask, Len) \ 1642 if (Char < 128) \ 1643 { \ 1644 Len = 1; \ 1645 Mask = 0x7f; \ 1646 } \ 1647 else if ((Char & 0xe0) == 0xc0) \ 1648 { \ 1649 Len = 2; \ 1650 Mask = 0x1f; \ 1651 } \ 1652 else if ((Char & 0xf0) == 0xe0) \ 1653 { \ 1654 Len = 3; \ 1655 Mask = 0x0f; \ 1656 } \ 1657 else if ((Char & 0xf8) == 0xf0) \ 1658 { \ 1659 Len = 4; \ 1660 Mask = 0x07; \ 1661 } \ 1662 else if ((Char & 0xfc) == 0xf8) \ 1663 { \ 1664 Len = 5; \ 1665 Mask = 0x03; \ 1666 } \ 1667 else if ((Char & 0xfe) == 0xfc) \ 1668 { \ 1669 Len = 6; \ 1670 Mask = 0x01; \ 1671 } \ 1672 else \ 1673 { \ 1674 Len = 0; \ 1675 Mask = 0; \ 1676 } 1677 1678 /** 1679 * computes length of a unicode character in UTF-8 1680 * @param Char the char 1681 */ 1682 #define UTF8_LENGTH(Char) \ 1683 ((Char) < 0x80 ? 1 : \ 1684 ((Char) < 0x800 ? 2 : \ 1685 ((Char) < 0x10000 ? 3 : \ 1686 ((Char) < 0x200000 ? 4 : \ 1687 ((Char) < 0x4000000 ? 5 : 6))))) 1688 1689 /** 1690 * Gets a UTF-8 value. 1691 * 1692 * @param Result variable for extracted unicode char. 1693 * @param Chars the bytes to decode 1694 * @param Count counter variable 1695 * @param Mask mask for this char 1696 * @param Len length for this char in bytes 1697 */ 1698 #define UTF8_GET(Result, Chars, Count, Mask, Len) \ 1699 (Result) = (Chars)[0] & (Mask); \ 1700 for ((Count) = 1; (Count) < (Len); ++(Count)) \ 1701 { \ 1702 if (((Chars)[(Count)] & 0xc0) != 0x80) \ 1703 { \ 1704 (Result) = -1; \ 1705 break; \ 1706 } \ 1707 (Result) <<= 6; \ 1708 (Result) |= ((Chars)[(Count)] & 0x3f); \ 1709 } 1710 1711 /** 1712 * Check whether a unicode char is in a valid range. 1713 * 1714 * @param Char the character 1715 */ 1716 #define UNICODE_VALID(Char) \ 1717 ((Char) < 0x110000 && \ 1718 (((Char) & 0xFFFFF800) != 0xD800) && \ 1719 ((Char) < 0xFDD0 || (Char) > 0xFDEF) && \ 1720 ((Char) & 0xFFFF) != 0xFFFF) 1721 1722 #ifdef DBUS_BUILD_TESTS 1723 /** 1724 * Gets a unicode character from a UTF-8 string. Does no validation; 1725 * you must verify that the string is valid UTF-8 in advance and must 1726 * pass in the start of a character. 1727 * 1728 * @param str the string 1729 * @param start the start of the UTF-8 character. 1730 * @param ch_return location to return the character 1731 * @param end_return location to return the byte index of next character 1732 */ 1733 void 1734 _dbus_string_get_unichar (const DBusString *str, 1735 int start, 1736 dbus_unichar_t *ch_return, 1737 int *end_return) 1738 { 1739 int i, mask, len; 1740 dbus_unichar_t result; 1741 unsigned char c; 1742 unsigned char *p; 1743 DBUS_CONST_STRING_PREAMBLE (str); 1744 _dbus_assert (start >= 0); 1745 _dbus_assert (start <= real->len); 1746 1747 if (ch_return) 1748 *ch_return = 0; 1749 if (end_return) 1750 *end_return = real->len; 1751 1752 mask = 0; 1753 p = real->str + start; 1754 c = *p; 1755 1756 UTF8_COMPUTE (c, mask, len); 1757 if (len == 0) 1758 return; 1759 UTF8_GET (result, p, i, mask, len); 1760 1761 if (result == (dbus_unichar_t)-1) 1762 return; 1763 1764 if (ch_return) 1765 *ch_return = result; 1766 if (end_return) 1767 *end_return = start + len; 1768 } 1769 #endif /* DBUS_BUILD_TESTS */ 1770 1771 /** 1772 * Finds the given substring in the string, 1773 * returning #TRUE and filling in the byte index 1774 * where the substring was found, if it was found. 1775 * Returns #FALSE if the substring wasn't found. 1776 * Sets *start to the length of the string if the substring 1777 * is not found. 1778 * 1779 * @param str the string 1780 * @param start where to start looking 1781 * @param substr the substring 1782 * @param found return location for where it was found, or #NULL 1783 * @returns #TRUE if found 1784 */ 1785 dbus_bool_t 1786 _dbus_string_find (const DBusString *str, 1787 int start, 1788 const char *substr, 1789 int *found) 1790 { 1791 return _dbus_string_find_to (str, start, 1792 ((const DBusRealString*)str)->len, 1793 substr, found); 1794 } 1795 1796 /** 1797 * Finds the given substring in the string, 1798 * up to a certain position, 1799 * returning #TRUE and filling in the byte index 1800 * where the substring was found, if it was found. 1801 * Returns #FALSE if the substring wasn't found. 1802 * Sets *start to the length of the string if the substring 1803 * is not found. 1804 * 1805 * @param str the string 1806 * @param start where to start looking 1807 * @param end where to stop looking 1808 * @param substr the substring 1809 * @param found return location for where it was found, or #NULL 1810 * @returns #TRUE if found 1811 */ 1812 dbus_bool_t 1813 _dbus_string_find_to (const DBusString *str, 1814 int start, 1815 int end, 1816 const char *substr, 1817 int *found) 1818 { 1819 int i; 1820 DBUS_CONST_STRING_PREAMBLE (str); 1821 _dbus_assert (substr != NULL); 1822 _dbus_assert (start <= real->len); 1823 _dbus_assert (start >= 0); 1824 _dbus_assert (substr != NULL); 1825 _dbus_assert (end <= real->len); 1826 _dbus_assert (start <= end); 1827 1828 /* we always "find" an empty string */ 1829 if (*substr == '\0') 1830 { 1831 if (found) 1832 *found = start; 1833 return TRUE; 1834 } 1835 1836 i = start; 1837 while (i < end) 1838 { 1839 if (real->str[i] == substr[0]) 1840 { 1841 int j = i + 1; 1842 1843 while (j < end) 1844 { 1845 if (substr[j - i] == '\0') 1846 break; 1847 else if (real->str[j] != substr[j - i]) 1848 break; 1849 1850 ++j; 1851 } 1852 1853 if (substr[j - i] == '\0') 1854 { 1855 if (found) 1856 *found = i; 1857 return TRUE; 1858 } 1859 } 1860 1861 ++i; 1862 } 1863 1864 if (found) 1865 *found = end; 1866 1867 return FALSE; 1868 } 1869 1870 /** 1871 * Finds a blank (space or tab) in the string. Returns #TRUE 1872 * if found, #FALSE otherwise. If a blank is not found sets 1873 * *found to the length of the string. 1874 * 1875 * @param str the string 1876 * @param start byte index to start looking 1877 * @param found place to store the location of the first blank 1878 * @returns #TRUE if a blank was found 1879 */ 1880 dbus_bool_t 1881 _dbus_string_find_blank (const DBusString *str, 1882 int start, 1883 int *found) 1884 { 1885 int i; 1886 DBUS_CONST_STRING_PREAMBLE (str); 1887 _dbus_assert (start <= real->len); 1888 _dbus_assert (start >= 0); 1889 1890 i = start; 1891 while (i < real->len) 1892 { 1893 if (real->str[i] == ' ' || 1894 real->str[i] == '\t') 1895 { 1896 if (found) 1897 *found = i; 1898 return TRUE; 1899 } 1900 1901 ++i; 1902 } 1903 1904 if (found) 1905 *found = real->len; 1906 1907 return FALSE; 1908 } 1909 1910 /** 1911 * Skips blanks from start, storing the first non-blank in *end 1912 * (blank is space or tab). 1913 * 1914 * @param str the string 1915 * @param start where to start 1916 * @param end where to store the first non-blank byte index 1917 */ 1918 void 1919 _dbus_string_skip_blank (const DBusString *str, 1920 int start, 1921 int *end) 1922 { 1923 int i; 1924 DBUS_CONST_STRING_PREAMBLE (str); 1925 _dbus_assert (start <= real->len); 1926 _dbus_assert (start >= 0); 1927 1928 i = start; 1929 while (i < real->len) 1930 { 1931 if (!DBUS_IS_ASCII_BLANK (real->str[i])) 1932 break; 1933 1934 ++i; 1935 } 1936 1937 _dbus_assert (i == real->len || !DBUS_IS_ASCII_WHITE (real->str[i])); 1938 1939 if (end) 1940 *end = i; 1941 } 1942 1943 1944 /** 1945 * Skips whitespace from start, storing the first non-whitespace in *end. 1946 * (whitespace is space, tab, newline, CR). 1947 * 1948 * @param str the string 1949 * @param start where to start 1950 * @param end where to store the first non-whitespace byte index 1951 */ 1952 void 1953 _dbus_string_skip_white (const DBusString *str, 1954 int start, 1955 int *end) 1956 { 1957 int i; 1958 DBUS_CONST_STRING_PREAMBLE (str); 1959 _dbus_assert (start <= real->len); 1960 _dbus_assert (start >= 0); 1961 1962 i = start; 1963 while (i < real->len) 1964 { 1965 if (!DBUS_IS_ASCII_WHITE (real->str[i])) 1966 break; 1967 1968 ++i; 1969 } 1970 1971 _dbus_assert (i == real->len || !(DBUS_IS_ASCII_WHITE (real->str[i]))); 1972 1973 if (end) 1974 *end = i; 1975 } 1976 1977 /** 1978 * Skips whitespace from end, storing the start index of the trailing 1979 * whitespace in *start. (whitespace is space, tab, newline, CR). 1980 * 1981 * @param str the string 1982 * @param end where to start scanning backward 1983 * @param start where to store the start of whitespace chars 1984 */ 1985 void 1986 _dbus_string_skip_white_reverse (const DBusString *str, 1987 int end, 1988 int *start) 1989 { 1990 int i; 1991 DBUS_CONST_STRING_PREAMBLE (str); 1992 _dbus_assert (end <= real->len); 1993 _dbus_assert (end >= 0); 1994 1995 i = end; 1996 while (i > 0) 1997 { 1998 if (!DBUS_IS_ASCII_WHITE (real->str[i-1])) 1999 break; 2000 --i; 2001 } 2002 2003 _dbus_assert (i >= 0 && (i == 0 || !(DBUS_IS_ASCII_WHITE (real->str[i-1])))); 2004 2005 if (start) 2006 *start = i; 2007 } 2008 2009 /** 2010 * Assigns a newline-terminated or \\r\\n-terminated line from the front 2011 * of the string to the given dest string. The dest string's previous 2012 * contents are deleted. If the source string contains no newline, 2013 * moves the entire source string to the dest string. 2014 * 2015 * @todo owen correctly notes that this is a stupid function (it was 2016 * written purely for test code, 2017 * e.g. dbus-message-builder.c). Probably should be enforced as test 2018 * code only with ifdef DBUS_BUILD_TESTS 2019 * 2020 * @param source the source string 2021 * @param dest the destination string (contents are replaced) 2022 * @returns #FALSE if no memory, or source has length 0 2023 */ 2024 dbus_bool_t 2025 _dbus_string_pop_line (DBusString *source, 2026 DBusString *dest) 2027 { 2028 int eol; 2029 dbus_bool_t have_newline; 2030 2031 _dbus_string_set_length (dest, 0); 2032 2033 eol = 0; 2034 if (_dbus_string_find (source, 0, "\n", &eol)) 2035 { 2036 have_newline = TRUE; 2037 eol += 1; /* include newline */ 2038 } 2039 else 2040 { 2041 eol = _dbus_string_get_length (source); 2042 have_newline = FALSE; 2043 } 2044 2045 if (eol == 0) 2046 return FALSE; /* eof */ 2047 2048 if (!_dbus_string_move_len (source, 0, eol, 2049 dest, 0)) 2050 { 2051 return FALSE; 2052 } 2053 2054 /* dump the newline and the \r if we have one */ 2055 if (have_newline) 2056 { 2057 dbus_bool_t have_cr; 2058 2059 _dbus_assert (_dbus_string_get_length (dest) > 0); 2060 2061 if (_dbus_string_get_length (dest) > 1 && 2062 _dbus_string_get_byte (dest, 2063 _dbus_string_get_length (dest) - 2) == '\r') 2064 have_cr = TRUE; 2065 else 2066 have_cr = FALSE; 2067 2068 _dbus_string_set_length (dest, 2069 _dbus_string_get_length (dest) - 2070 (have_cr ? 2 : 1)); 2071 } 2072 2073 return TRUE; 2074 } 2075 2076 #ifdef DBUS_BUILD_TESTS 2077 /** 2078 * Deletes up to and including the first blank space 2079 * in the string. 2080 * 2081 * @param str the string 2082 */ 2083 void 2084 _dbus_string_delete_first_word (DBusString *str) 2085 { 2086 int i; 2087 2088 if (_dbus_string_find_blank (str, 0, &i)) 2089 _dbus_string_skip_blank (str, i, &i); 2090 2091 _dbus_string_delete (str, 0, i); 2092 } 2093 #endif 2094 2095 #ifdef DBUS_BUILD_TESTS 2096 /** 2097 * Deletes any leading blanks in the string 2098 * 2099 * @param str the string 2100 */ 2101 void 2102 _dbus_string_delete_leading_blanks (DBusString *str) 2103 { 2104 int i; 2105 2106 _dbus_string_skip_blank (str, 0, &i); 2107 2108 if (i > 0) 2109 _dbus_string_delete (str, 0, i); 2110 } 2111 #endif 2112 2113 /** 2114 * Deletes leading and trailing whitespace 2115 * 2116 * @param str the string 2117 */ 2118 void 2119 _dbus_string_chop_white(DBusString *str) 2120 { 2121 int i; 2122 2123 _dbus_string_skip_white (str, 0, &i); 2124 2125 if (i > 0) 2126 _dbus_string_delete (str, 0, i); 2127 2128 _dbus_string_skip_white_reverse (str, _dbus_string_get_length (str), &i); 2129 2130 _dbus_string_set_length (str, i); 2131 } 2132 2133 /** 2134 * Tests two DBusString for equality. 2135 * 2136 * @todo memcmp is probably faster 2137 * 2138 * @param a first string 2139 * @param b second string 2140 * @returns #TRUE if equal 2141 */ 2142 dbus_bool_t 2143 _dbus_string_equal (const DBusString *a, 2144 const DBusString *b) 2145 { 2146 const unsigned char *ap; 2147 const unsigned char *bp; 2148 const unsigned char *a_end; 2149 const DBusRealString *real_a = (const DBusRealString*) a; 2150 const DBusRealString *real_b = (const DBusRealString*) b; 2151 DBUS_GENERIC_STRING_PREAMBLE (real_a); 2152 DBUS_GENERIC_STRING_PREAMBLE (real_b); 2153 2154 if (real_a->len != real_b->len) 2155 return FALSE; 2156 2157 ap = real_a->str; 2158 bp = real_b->str; 2159 a_end = real_a->str + real_a->len; 2160 while (ap != a_end) 2161 { 2162 if (*ap != *bp) 2163 return FALSE; 2164 2165 ++ap; 2166 ++bp; 2167 } 2168 2169 return TRUE; 2170 } 2171 2172 #ifdef DBUS_BUILD_TESTS 2173 /** 2174 * Tests two DBusString for equality up to the given length. 2175 * The strings may be shorter than the given length. 2176 * 2177 * @todo write a unit test 2178 * 2179 * @todo memcmp is probably faster 2180 * 2181 * @param a first string 2182 * @param b second string 2183 * @param len the maximum length to look at 2184 * @returns #TRUE if equal for the given number of bytes 2185 */ 2186 dbus_bool_t 2187 _dbus_string_equal_len (const DBusString *a, 2188 const DBusString *b, 2189 int len) 2190 { 2191 const unsigned char *ap; 2192 const unsigned char *bp; 2193 const unsigned char *a_end; 2194 const DBusRealString *real_a = (const DBusRealString*) a; 2195 const DBusRealString *real_b = (const DBusRealString*) b; 2196 DBUS_GENERIC_STRING_PREAMBLE (real_a); 2197 DBUS_GENERIC_STRING_PREAMBLE (real_b); 2198 2199 if (real_a->len != real_b->len && 2200 (real_a->len < len || real_b->len < len)) 2201 return FALSE; 2202 2203 ap = real_a->str; 2204 bp = real_b->str; 2205 a_end = real_a->str + MIN (real_a->len, len); 2206 while (ap != a_end) 2207 { 2208 if (*ap != *bp) 2209 return FALSE; 2210 2211 ++ap; 2212 ++bp; 2213 } 2214 2215 return TRUE; 2216 } 2217 #endif /* DBUS_BUILD_TESTS */ 2218 2219 /** 2220 * Tests two sub-parts of two DBusString for equality. The specified 2221 * range of the first string must exist; the specified start position 2222 * of the second string must exist. 2223 * 2224 * @todo write a unit test 2225 * 2226 * @todo memcmp is probably faster 2227 * 2228 * @param a first string 2229 * @param a_start where to start substring in first string 2230 * @param a_len length of substring in first string 2231 * @param b second string 2232 * @param b_start where to start substring in second string 2233 * @returns #TRUE if the two substrings are equal 2234 */ 2235 dbus_bool_t 2236 _dbus_string_equal_substring (const DBusString *a, 2237 int a_start, 2238 int a_len, 2239 const DBusString *b, 2240 int b_start) 2241 { 2242 const unsigned char *ap; 2243 const unsigned char *bp; 2244 const unsigned char *a_end; 2245 const DBusRealString *real_a = (const DBusRealString*) a; 2246 const DBusRealString *real_b = (const DBusRealString*) b; 2247 DBUS_GENERIC_STRING_PREAMBLE (real_a); 2248 DBUS_GENERIC_STRING_PREAMBLE (real_b); 2249 _dbus_assert (a_start >= 0); 2250 _dbus_assert (a_len >= 0); 2251 _dbus_assert (a_start <= real_a->len); 2252 _dbus_assert (a_len <= real_a->len - a_start); 2253 _dbus_assert (b_start >= 0); 2254 _dbus_assert (b_start <= real_b->len); 2255 2256 if (a_len > real_b->len - b_start) 2257 return FALSE; 2258 2259 ap = real_a->str + a_start; 2260 bp = real_b->str + b_start; 2261 a_end = ap + a_len; 2262 while (ap != a_end) 2263 { 2264 if (*ap != *bp) 2265 return FALSE; 2266 2267 ++ap; 2268 ++bp; 2269 } 2270 2271 _dbus_assert (bp <= (real_b->str + real_b->len)); 2272 2273 return TRUE; 2274 } 2275 2276 /** 2277 * Checks whether a string is equal to a C string. 2278 * 2279 * @param a the string 2280 * @param c_str the C string 2281 * @returns #TRUE if equal 2282 */ 2283 dbus_bool_t 2284 _dbus_string_equal_c_str (const DBusString *a, 2285 const char *c_str) 2286 { 2287 const unsigned char *ap; 2288 const unsigned char *bp; 2289 const unsigned char *a_end; 2290 const DBusRealString *real_a = (const DBusRealString*) a; 2291 DBUS_GENERIC_STRING_PREAMBLE (real_a); 2292 _dbus_assert (c_str != NULL); 2293 2294 ap = real_a->str; 2295 bp = (const unsigned char*) c_str; 2296 a_end = real_a->str + real_a->len; 2297 while (ap != a_end && *bp) 2298 { 2299 if (*ap != *bp) 2300 return FALSE; 2301 2302 ++ap; 2303 ++bp; 2304 } 2305 2306 if (ap != a_end || *bp) 2307 return FALSE; 2308 2309 return TRUE; 2310 } 2311 2312 #ifdef DBUS_BUILD_TESTS 2313 /** 2314 * Checks whether a string starts with the given C string. 2315 * 2316 * @param a the string 2317 * @param c_str the C string 2318 * @returns #TRUE if string starts with it 2319 */ 2320 dbus_bool_t 2321 _dbus_string_starts_with_c_str (const DBusString *a, 2322 const char *c_str) 2323 { 2324 const unsigned char *ap; 2325 const unsigned char *bp; 2326 const unsigned char *a_end; 2327 const DBusRealString *real_a = (const DBusRealString*) a; 2328 DBUS_GENERIC_STRING_PREAMBLE (real_a); 2329 _dbus_assert (c_str != NULL); 2330 2331 ap = real_a->str; 2332 bp = (const unsigned char*) c_str; 2333 a_end = real_a->str + real_a->len; 2334 while (ap != a_end && *bp) 2335 { 2336 if (*ap != *bp) 2337 return FALSE; 2338 2339 ++ap; 2340 ++bp; 2341 } 2342 2343 if (*bp == '\0') 2344 return TRUE; 2345 else 2346 return FALSE; 2347 } 2348 #endif /* DBUS_BUILD_TESTS */ 2349 2350 /** 2351 * Appends a two-character hex digit to a string, where the hex digit 2352 * has the value of the given byte. 2353 * 2354 * @param str the string 2355 * @param byte the byte 2356 * @returns #FALSE if no memory 2357 */ 2358 dbus_bool_t 2359 _dbus_string_append_byte_as_hex (DBusString *str, 2360 int byte) 2361 { 2362 const char hexdigits[16] = { 2363 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 2364 'a', 'b', 'c', 'd', 'e', 'f' 2365 }; 2366 2367 if (!_dbus_string_append_byte (str, 2368 hexdigits[(byte >> 4)])) 2369 return FALSE; 2370 2371 if (!_dbus_string_append_byte (str, 2372 hexdigits[(byte & 0x0f)])) 2373 { 2374 _dbus_string_set_length (str, 2375 _dbus_string_get_length (str) - 1); 2376 return FALSE; 2377 } 2378 2379 return TRUE; 2380 } 2381 2382 /** 2383 * Encodes a string in hex, the way MD5 and SHA-1 are usually 2384 * encoded. (Each byte is two hex digits.) 2385 * 2386 * @param source the string to encode 2387 * @param start byte index to start encoding 2388 * @param dest string where encoded data should be placed 2389 * @param insert_at where to place encoded data 2390 * @returns #TRUE if encoding was successful, #FALSE if no memory etc. 2391 */ 2392 dbus_bool_t 2393 _dbus_string_hex_encode (const DBusString *source, 2394 int start, 2395 DBusString *dest, 2396 int insert_at) 2397 { 2398 DBusString result; 2399 const unsigned char *p; 2400 const unsigned char *end; 2401 dbus_bool_t retval; 2402 2403 _dbus_assert (start <= _dbus_string_get_length (source)); 2404 2405 if (!_dbus_string_init (&result)) 2406 return FALSE; 2407 2408 retval = FALSE; 2409 2410 p = (const unsigned char*) _dbus_string_get_const_data (source); 2411 end = p + _dbus_string_get_length (source); 2412 p += start; 2413 2414 while (p != end) 2415 { 2416 if (!_dbus_string_append_byte_as_hex (&result, *p)) 2417 goto out; 2418 2419 ++p; 2420 } 2421 2422 if (!_dbus_string_move (&result, 0, dest, insert_at)) 2423 goto out; 2424 2425 retval = TRUE; 2426 2427 out: 2428 _dbus_string_free (&result); 2429 return retval; 2430 } 2431 2432 /** 2433 * Decodes a string from hex encoding. 2434 * 2435 * @param source the string to decode 2436 * @param start byte index to start decode 2437 * @param end_return return location of the end of the hex data, or #NULL 2438 * @param dest string where decoded data should be placed 2439 * @param insert_at where to place decoded data 2440 * @returns #TRUE if decoding was successful, #FALSE if no memory. 2441 */ 2442 dbus_bool_t 2443 _dbus_string_hex_decode (const DBusString *source, 2444 int start, 2445 int *end_return, 2446 DBusString *dest, 2447 int insert_at) 2448 { 2449 DBusString result; 2450 const unsigned char *p; 2451 const unsigned char *end; 2452 dbus_bool_t retval; 2453 dbus_bool_t high_bits; 2454 2455 _dbus_assert (start <= _dbus_string_get_length (source)); 2456 2457 if (!_dbus_string_init (&result)) 2458 return FALSE; 2459 2460 retval = FALSE; 2461 2462 high_bits = TRUE; 2463 p = (const unsigned char*) _dbus_string_get_const_data (source); 2464 end = p + _dbus_string_get_length (source); 2465 p += start; 2466 2467 while (p != end) 2468 { 2469 unsigned int val; 2470 2471 switch (*p) 2472 { 2473 case '0': 2474 val = 0; 2475 break; 2476 case '1': 2477 val = 1; 2478 break; 2479 case '2': 2480 val = 2; 2481 break; 2482 case '3': 2483 val = 3; 2484 break; 2485 case '4': 2486 val = 4; 2487 break; 2488 case '5': 2489 val = 5; 2490 break; 2491 case '6': 2492 val = 6; 2493 break; 2494 case '7': 2495 val = 7; 2496 break; 2497 case '8': 2498 val = 8; 2499 break; 2500 case '9': 2501 val = 9; 2502 break; 2503 case 'a': 2504 case 'A': 2505 val = 10; 2506 break; 2507 case 'b': 2508 case 'B': 2509 val = 11; 2510 break; 2511 case 'c': 2512 case 'C': 2513 val = 12; 2514 break; 2515 case 'd': 2516 case 'D': 2517 val = 13; 2518 break; 2519 case 'e': 2520 case 'E': 2521 val = 14; 2522 break; 2523 case 'f': 2524 case 'F': 2525 val = 15; 2526 break; 2527 default: 2528 goto done; 2529 } 2530 2531 if (high_bits) 2532 { 2533 if (!_dbus_string_append_byte (&result, 2534 val << 4)) 2535 goto out; 2536 } 2537 else 2538 { 2539 int len; 2540 unsigned char b; 2541 2542 len = _dbus_string_get_length (&result); 2543 2544 b = _dbus_string_get_byte (&result, len - 1); 2545 2546 b |= val; 2547 2548 _dbus_string_set_byte (&result, len - 1, b); 2549 } 2550 2551 high_bits = !high_bits; 2552 2553 ++p; 2554 } 2555 2556 done: 2557 if (!_dbus_string_move (&result, 0, dest, insert_at)) 2558 goto out; 2559 2560 if (end_return) 2561 *end_return = p - (const unsigned char*) _dbus_string_get_const_data (source); 2562 2563 retval = TRUE; 2564 2565 out: 2566 _dbus_string_free (&result); 2567 return retval; 2568 } 2569 2570 /** 2571 * Checks that the given range of the string is valid ASCII with no 2572 * nul bytes. If the given range is not entirely contained in the 2573 * string, returns #FALSE. 2574 * 2575 * @todo this is inconsistent with most of DBusString in that 2576 * it allows a start,len range that extends past the string end. 2577 * 2578 * @param str the string 2579 * @param start first byte index to check 2580 * @param len number of bytes to check 2581 * @returns #TRUE if the byte range exists and is all valid ASCII 2582 */ 2583 dbus_bool_t 2584 _dbus_string_validate_ascii (const DBusString *str, 2585 int start, 2586 int len) 2587 { 2588 const unsigned char *s; 2589 const unsigned char *end; 2590 DBUS_CONST_STRING_PREAMBLE (str); 2591 _dbus_assert (start >= 0); 2592 _dbus_assert (start <= real->len); 2593 _dbus_assert (len >= 0); 2594 2595 if (len > real->len - start) 2596 return FALSE; 2597 2598 s = real->str + start; 2599 end = s + len; 2600 while (s != end) 2601 { 2602 if (_DBUS_UNLIKELY (!_DBUS_ISASCII (*s))) 2603 return FALSE; 2604 2605 ++s; 2606 } 2607 2608 return TRUE; 2609 } 2610 2611 /** 2612 * Checks that the given range of the string is valid UTF-8. If the 2613 * given range is not entirely contained in the string, returns 2614 * #FALSE. If the string contains any nul bytes in the given range, 2615 * returns #FALSE. If the start and start+len are not on character 2616 * boundaries, returns #FALSE. 2617 * 2618 * @todo this is inconsistent with most of DBusString in that 2619 * it allows a start,len range that extends past the string end. 2620 * 2621 * @param str the string 2622 * @param start first byte index to check 2623 * @param len number of bytes to check 2624 * @returns #TRUE if the byte range exists and is all valid UTF-8 2625 */ 2626 dbus_bool_t 2627 _dbus_string_validate_utf8 (const DBusString *str, 2628 int start, 2629 int len) 2630 { 2631 const unsigned char *p; 2632 const unsigned char *end; 2633 DBUS_CONST_STRING_PREAMBLE (str); 2634 _dbus_assert (start >= 0); 2635 _dbus_assert (start <= real->len); 2636 _dbus_assert (len >= 0); 2637 2638 /* we are doing _DBUS_UNLIKELY() here which might be 2639 * dubious in a generic library like GLib, but in D-Bus 2640 * we know we're validating messages and that it would 2641 * only be evil/broken apps that would have invalid 2642 * UTF-8. Also, this function seems to be a performance 2643 * bottleneck in profiles. 2644 */ 2645 2646 if (_DBUS_UNLIKELY (len > real->len - start)) 2647 return FALSE; 2648 2649 p = real->str + start; 2650 end = p + len; 2651 2652 while (p < end) 2653 { 2654 int i, mask, char_len; 2655 dbus_unichar_t result; 2656 2657 /* nul bytes considered invalid */ 2658 if (*p == '\0') 2659 break; 2660 2661 /* Special-case ASCII; this makes us go a lot faster in 2662 * D-Bus profiles where we are typically validating 2663 * function names and such. We have to know that 2664 * all following checks will pass for ASCII though, 2665 * comments follow ... 2666 */ 2667 if (*p < 128) 2668 { 2669 ++p; 2670 continue; 2671 } 2672 2673 UTF8_COMPUTE (*p, mask, char_len); 2674 2675 if (_DBUS_UNLIKELY (char_len == 0)) /* ASCII: char_len == 1 */ 2676 break; 2677 2678 /* check that the expected number of bytes exists in the remaining length */ 2679 if (_DBUS_UNLIKELY ((end - p) < char_len)) /* ASCII: p < end and char_len == 1 */ 2680 break; 2681 2682 UTF8_GET (result, p, i, mask, char_len); 2683 2684 /* Check for overlong UTF-8 */ 2685 if (_DBUS_UNLIKELY (UTF8_LENGTH (result) != char_len)) /* ASCII: UTF8_LENGTH == 1 */ 2686 break; 2687 #if 0 2688 /* The UNICODE_VALID check below will catch this */ 2689 if (_DBUS_UNLIKELY (result == (dbus_unichar_t)-1)) /* ASCII: result = ascii value */ 2690 break; 2691 #endif 2692 2693 if (_DBUS_UNLIKELY (!UNICODE_VALID (result))) /* ASCII: always valid */ 2694 break; 2695 2696 /* UNICODE_VALID should have caught it */ 2697 _dbus_assert (result != (dbus_unichar_t)-1); 2698 2699 p += char_len; 2700 } 2701 2702 /* See that we covered the entire length if a length was 2703 * passed in 2704 */ 2705 if (_DBUS_UNLIKELY (p != end)) 2706 return FALSE; 2707 else 2708 return TRUE; 2709 } 2710 2711 /** 2712 * Checks that the given range of the string is all nul bytes. If the 2713 * given range is not entirely contained in the string, returns 2714 * #FALSE. 2715 * 2716 * @todo this is inconsistent with most of DBusString in that 2717 * it allows a start,len range that extends past the string end. 2718 * 2719 * @param str the string 2720 * @param start first byte index to check 2721 * @param len number of bytes to check 2722 * @returns #TRUE if the byte range exists and is all nul bytes 2723 */ 2724 dbus_bool_t 2725 _dbus_string_validate_nul (const DBusString *str, 2726 int start, 2727 int len) 2728 { 2729 const unsigned char *s; 2730 const unsigned char *end; 2731 DBUS_CONST_STRING_PREAMBLE (str); 2732 _dbus_assert (start >= 0); 2733 _dbus_assert (len >= 0); 2734 _dbus_assert (start <= real->len); 2735 2736 if (len > real->len - start) 2737 return FALSE; 2738 2739 s = real->str + start; 2740 end = s + len; 2741 while (s != end) 2742 { 2743 if (_DBUS_UNLIKELY (*s != '\0')) 2744 return FALSE; 2745 ++s; 2746 } 2747 2748 return TRUE; 2749 } 2750 2751 /** 2752 * Clears all allocated bytes in the string to zero. 2753 * 2754 * @param str the string 2755 */ 2756 void 2757 _dbus_string_zero (DBusString *str) 2758 { 2759 DBUS_STRING_PREAMBLE (str); 2760 2761 memset (real->str - real->align_offset, '\0', real->allocated); 2762 } 2763 /** @} */ 2764 2765 /* tests are in dbus-string-util.c */ 2766
