1 /* 2 * buf.c: memory buffers for libxml2 3 * 4 * new buffer structures and entry points to simplify the maintainance 5 * of libxml2 and ensure we keep good control over memory allocations 6 * and stay 64 bits clean. 7 * The new entry point use the xmlBufPtr opaque structure and 8 * xmlBuf...() counterparts to the old xmlBuf...() functions 9 * 10 * See Copyright for the status of this software. 11 * 12 * daniel (at) veillard.com 13 */ 14 15 #define IN_LIBXML 16 #include "libxml.h" 17 18 #include <string.h> /* for memset() only ! */ 19 #include <limits.h> 20 #ifdef HAVE_CTYPE_H 21 #include <ctype.h> 22 #endif 23 #ifdef HAVE_STDLIB_H 24 #include <stdlib.h> 25 #endif 26 27 #include <libxml/tree.h> 28 #include <libxml/globals.h> 29 #include <libxml/tree.h> 30 #include <libxml/parserInternals.h> /* for XML_MAX_TEXT_LENGTH */ 31 #include "buf.h" 32 33 #define WITH_BUFFER_COMPAT 34 35 /** 36 * xmlBuf: 37 * 38 * A buffer structure. The base of the structure is somehow compatible 39 * with struct _xmlBuffer to limit risks on application which accessed 40 * directly the input->buf->buffer structures. 41 */ 42 43 struct _xmlBuf { 44 xmlChar *content; /* The buffer content UTF8 */ 45 unsigned int compat_use; /* for binary compatibility */ 46 unsigned int compat_size; /* for binary compatibility */ 47 xmlBufferAllocationScheme alloc; /* The realloc method */ 48 xmlChar *contentIO; /* in IO mode we may have a different base */ 49 size_t use; /* The buffer size used */ 50 size_t size; /* The buffer size */ 51 xmlBufferPtr buffer; /* wrapper for an old buffer */ 52 int error; /* an error code if a failure occurred */ 53 }; 54 55 #ifdef WITH_BUFFER_COMPAT 56 /* 57 * Macro for compatibility with xmlBuffer to be used after an xmlBuf 58 * is updated. This makes sure the compat fields are updated too. 59 */ 60 #define UPDATE_COMPAT(buf) \ 61 if (buf->size < INT_MAX) buf->compat_size = buf->size; \ 62 else buf->compat_size = INT_MAX; \ 63 if (buf->use < INT_MAX) buf->compat_use = buf->use; \ 64 else buf->compat_use = INT_MAX; 65 66 /* 67 * Macro for compatibility with xmlBuffer to be used in all the xmlBuf 68 * entry points, it checks that the compat fields have not been modified 69 * by direct call to xmlBuffer function from code compiled before 2.9.0 . 70 */ 71 #define CHECK_COMPAT(buf) \ 72 if (buf->size != (size_t) buf->compat_size) \ 73 if (buf->compat_size < INT_MAX) \ 74 buf->size = buf->compat_size; \ 75 if (buf->use != (size_t) buf->compat_use) \ 76 if (buf->compat_use < INT_MAX) \ 77 buf->use = buf->compat_use; 78 79 #else /* ! WITH_BUFFER_COMPAT */ 80 #define UPDATE_COMPAT(buf) 81 #define CHECK_COMPAT(buf) 82 #endif /* WITH_BUFFER_COMPAT */ 83 84 /** 85 * xmlBufMemoryError: 86 * @extra: extra informations 87 * 88 * Handle an out of memory condition 89 * To be improved... 90 */ 91 static void 92 xmlBufMemoryError(xmlBufPtr buf, const char *extra) 93 { 94 __xmlSimpleError(XML_FROM_BUFFER, XML_ERR_NO_MEMORY, NULL, NULL, extra); 95 if ((buf) && (buf->error == 0)) 96 buf->error = XML_ERR_NO_MEMORY; 97 } 98 99 /** 100 * xmlBufOverflowError: 101 * @extra: extra informations 102 * 103 * Handle a buffer overflow error 104 * To be improved... 105 */ 106 static void 107 xmlBufOverflowError(xmlBufPtr buf, const char *extra) 108 { 109 __xmlSimpleError(XML_FROM_BUFFER, XML_BUF_OVERFLOW, NULL, NULL, extra); 110 if ((buf) && (buf->error == 0)) 111 buf->error = XML_BUF_OVERFLOW; 112 } 113 114 115 /** 116 * xmlBufCreate: 117 * 118 * routine to create an XML buffer. 119 * returns the new structure. 120 */ 121 xmlBufPtr 122 xmlBufCreate(void) { 123 xmlBufPtr ret; 124 125 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); 126 if (ret == NULL) { 127 xmlBufMemoryError(NULL, "creating buffer"); 128 return(NULL); 129 } 130 ret->compat_use = 0; 131 ret->use = 0; 132 ret->error = 0; 133 ret->buffer = NULL; 134 ret->size = xmlDefaultBufferSize; 135 ret->compat_size = xmlDefaultBufferSize; 136 ret->alloc = xmlBufferAllocScheme; 137 ret->content = (xmlChar *) xmlMallocAtomic(ret->size * sizeof(xmlChar)); 138 if (ret->content == NULL) { 139 xmlBufMemoryError(ret, "creating buffer"); 140 xmlFree(ret); 141 return(NULL); 142 } 143 ret->content[0] = 0; 144 ret->contentIO = NULL; 145 return(ret); 146 } 147 148 /** 149 * xmlBufCreateSize: 150 * @size: initial size of buffer 151 * 152 * routine to create an XML buffer. 153 * returns the new structure. 154 */ 155 xmlBufPtr 156 xmlBufCreateSize(size_t size) { 157 xmlBufPtr ret; 158 159 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); 160 if (ret == NULL) { 161 xmlBufMemoryError(NULL, "creating buffer"); 162 return(NULL); 163 } 164 ret->compat_use = 0; 165 ret->use = 0; 166 ret->error = 0; 167 ret->buffer = NULL; 168 ret->alloc = xmlBufferAllocScheme; 169 ret->size = (size ? size+2 : 0); /* +1 for ending null */ 170 ret->compat_size = (int) ret->size; 171 if (ret->size){ 172 ret->content = (xmlChar *) xmlMallocAtomic(ret->size * sizeof(xmlChar)); 173 if (ret->content == NULL) { 174 xmlBufMemoryError(ret, "creating buffer"); 175 xmlFree(ret); 176 return(NULL); 177 } 178 ret->content[0] = 0; 179 } else 180 ret->content = NULL; 181 ret->contentIO = NULL; 182 return(ret); 183 } 184 185 /** 186 * xmlBufDetach: 187 * @buf: the buffer 188 * 189 * Remove the string contained in a buffer and give it back to the 190 * caller. The buffer is reset to an empty content. 191 * This doesn't work with immutable buffers as they can't be reset. 192 * 193 * Returns the previous string contained by the buffer. 194 */ 195 xmlChar * 196 xmlBufDetach(xmlBufPtr buf) { 197 xmlChar *ret; 198 199 if (buf == NULL) 200 return(NULL); 201 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) 202 return(NULL); 203 if (buf->buffer != NULL) 204 return(NULL); 205 if (buf->error) 206 return(NULL); 207 208 ret = buf->content; 209 buf->content = NULL; 210 buf->size = 0; 211 buf->use = 0; 212 buf->compat_use = 0; 213 buf->compat_size = 0; 214 215 return ret; 216 } 217 218 219 /** 220 * xmlBufCreateStatic: 221 * @mem: the memory area 222 * @size: the size in byte 223 * 224 * routine to create an XML buffer from an immutable memory area. 225 * The area won't be modified nor copied, and is expected to be 226 * present until the end of the buffer lifetime. 227 * 228 * returns the new structure. 229 */ 230 xmlBufPtr 231 xmlBufCreateStatic(void *mem, size_t size) { 232 xmlBufPtr ret; 233 234 if (mem == NULL) 235 return(NULL); 236 237 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); 238 if (ret == NULL) { 239 xmlBufMemoryError(NULL, "creating buffer"); 240 return(NULL); 241 } 242 if (size < INT_MAX) { 243 ret->compat_use = size; 244 ret->compat_size = size; 245 } else { 246 ret->compat_use = INT_MAX; 247 ret->compat_size = INT_MAX; 248 } 249 ret->use = size; 250 ret->size = size; 251 ret->alloc = XML_BUFFER_ALLOC_IMMUTABLE; 252 ret->content = (xmlChar *) mem; 253 ret->error = 0; 254 ret->buffer = NULL; 255 return(ret); 256 } 257 258 /** 259 * xmlBufGetAllocationScheme: 260 * @buf: the buffer 261 * 262 * Get the buffer allocation scheme 263 * 264 * Returns the scheme or -1 in case of error 265 */ 266 int 267 xmlBufGetAllocationScheme(xmlBufPtr buf) { 268 if (buf == NULL) { 269 #ifdef DEBUG_BUFFER 270 xmlGenericError(xmlGenericErrorContext, 271 "xmlBufGetAllocationScheme: buf == NULL\n"); 272 #endif 273 return(-1); 274 } 275 return(buf->alloc); 276 } 277 278 /** 279 * xmlBufSetAllocationScheme: 280 * @buf: the buffer to tune 281 * @scheme: allocation scheme to use 282 * 283 * Sets the allocation scheme for this buffer 284 * 285 * returns 0 in case of success and -1 in case of failure 286 */ 287 int 288 xmlBufSetAllocationScheme(xmlBufPtr buf, 289 xmlBufferAllocationScheme scheme) { 290 if ((buf == NULL) || (buf->error != 0)) { 291 #ifdef DEBUG_BUFFER 292 xmlGenericError(xmlGenericErrorContext, 293 "xmlBufSetAllocationScheme: buf == NULL or in error\n"); 294 #endif 295 return(-1); 296 } 297 if ((buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) || 298 (buf->alloc == XML_BUFFER_ALLOC_IO)) 299 return(-1); 300 if ((scheme == XML_BUFFER_ALLOC_DOUBLEIT) || 301 (scheme == XML_BUFFER_ALLOC_EXACT) || 302 (scheme == XML_BUFFER_ALLOC_HYBRID) || 303 (scheme == XML_BUFFER_ALLOC_IMMUTABLE) || 304 (scheme == XML_BUFFER_ALLOC_BOUNDED)) { 305 buf->alloc = scheme; 306 if (buf->buffer) 307 buf->buffer->alloc = scheme; 308 return(0); 309 } 310 /* 311 * Switching a buffer ALLOC_IO has the side effect of initializing 312 * the contentIO field with the current content 313 */ 314 if (scheme == XML_BUFFER_ALLOC_IO) { 315 buf->alloc = XML_BUFFER_ALLOC_IO; 316 buf->contentIO = buf->content; 317 } 318 return(-1); 319 } 320 321 /** 322 * xmlBufFree: 323 * @buf: the buffer to free 324 * 325 * Frees an XML buffer. It frees both the content and the structure which 326 * encapsulate it. 327 */ 328 void 329 xmlBufFree(xmlBufPtr buf) { 330 if (buf == NULL) { 331 #ifdef DEBUG_BUFFER 332 xmlGenericError(xmlGenericErrorContext, 333 "xmlBufFree: buf == NULL\n"); 334 #endif 335 return; 336 } 337 338 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && 339 (buf->contentIO != NULL)) { 340 xmlFree(buf->contentIO); 341 } else if ((buf->content != NULL) && 342 (buf->alloc != XML_BUFFER_ALLOC_IMMUTABLE)) { 343 xmlFree(buf->content); 344 } 345 xmlFree(buf); 346 } 347 348 /** 349 * xmlBufEmpty: 350 * @buf: the buffer 351 * 352 * empty a buffer. 353 */ 354 void 355 xmlBufEmpty(xmlBufPtr buf) { 356 if ((buf == NULL) || (buf->error != 0)) return; 357 if (buf->content == NULL) return; 358 CHECK_COMPAT(buf) 359 buf->use = 0; 360 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) { 361 buf->content = BAD_CAST ""; 362 } else if ((buf->alloc == XML_BUFFER_ALLOC_IO) && 363 (buf->contentIO != NULL)) { 364 size_t start_buf = buf->content - buf->contentIO; 365 366 buf->size += start_buf; 367 buf->content = buf->contentIO; 368 buf->content[0] = 0; 369 } else { 370 buf->content[0] = 0; 371 } 372 UPDATE_COMPAT(buf) 373 } 374 375 /** 376 * xmlBufShrink: 377 * @buf: the buffer to dump 378 * @len: the number of xmlChar to remove 379 * 380 * Remove the beginning of an XML buffer. 381 * NOTE that this routine behaviour differs from xmlBufferShrink() 382 * as it will return 0 on error instead of -1 due to size_t being 383 * used as the return type. 384 * 385 * Returns the number of byte removed or 0 in case of failure 386 */ 387 size_t 388 xmlBufShrink(xmlBufPtr buf, size_t len) { 389 if ((buf == NULL) || (buf->error != 0)) return(0); 390 CHECK_COMPAT(buf) 391 if (len == 0) return(0); 392 if (len > buf->use) return(0); 393 394 buf->use -= len; 395 if ((buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) || 396 ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL))) { 397 /* 398 * we just move the content pointer, but also make sure 399 * the perceived buffer size has shrinked accordingly 400 */ 401 buf->content += len; 402 buf->size -= len; 403 404 /* 405 * sometimes though it maybe be better to really shrink 406 * on IO buffers 407 */ 408 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { 409 size_t start_buf = buf->content - buf->contentIO; 410 if (start_buf >= buf->size) { 411 memmove(buf->contentIO, &buf->content[0], buf->use); 412 buf->content = buf->contentIO; 413 buf->content[buf->use] = 0; 414 buf->size += start_buf; 415 } 416 } 417 } else { 418 memmove(buf->content, &buf->content[len], buf->use); 419 buf->content[buf->use] = 0; 420 } 421 UPDATE_COMPAT(buf) 422 return(len); 423 } 424 425 /** 426 * xmlBufGrowInternal: 427 * @buf: the buffer 428 * @len: the minimum free size to allocate 429 * 430 * Grow the available space of an XML buffer, @len is the target value 431 * Error checking should be done on buf->error since using the return 432 * value doesn't work that well 433 * 434 * Returns 0 in case of error or the length made available otherwise 435 */ 436 static size_t 437 xmlBufGrowInternal(xmlBufPtr buf, size_t len) { 438 size_t size; 439 xmlChar *newbuf; 440 441 if ((buf == NULL) || (buf->error != 0)) return(0); 442 CHECK_COMPAT(buf) 443 444 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0); 445 if (buf->use + len < buf->size) 446 return(buf->size - buf->use); 447 448 /* 449 * Windows has a BIG problem on realloc timing, so we try to double 450 * the buffer size (if that's enough) (bug 146697) 451 * Apparently BSD too, and it's probably best for linux too 452 * On an embedded system this may be something to change 453 */ 454 #if 1 455 if (buf->size > (size_t) len) 456 size = buf->size * 2; 457 else 458 size = buf->use + len + 100; 459 #else 460 size = buf->use + len + 100; 461 #endif 462 463 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) { 464 /* 465 * Used to provide parsing limits 466 */ 467 if ((buf->use + len >= XML_MAX_TEXT_LENGTH) || 468 (buf->size >= XML_MAX_TEXT_LENGTH)) { 469 xmlBufMemoryError(buf, "buffer error: text too long\n"); 470 return(0); 471 } 472 if (size >= XML_MAX_TEXT_LENGTH) 473 size = XML_MAX_TEXT_LENGTH; 474 } 475 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { 476 size_t start_buf = buf->content - buf->contentIO; 477 478 newbuf = (xmlChar *) xmlRealloc(buf->contentIO, start_buf + size); 479 if (newbuf == NULL) { 480 xmlBufMemoryError(buf, "growing buffer"); 481 return(0); 482 } 483 buf->contentIO = newbuf; 484 buf->content = newbuf + start_buf; 485 } else { 486 newbuf = (xmlChar *) xmlRealloc(buf->content, size); 487 if (newbuf == NULL) { 488 xmlBufMemoryError(buf, "growing buffer"); 489 return(0); 490 } 491 buf->content = newbuf; 492 } 493 buf->size = size; 494 UPDATE_COMPAT(buf) 495 return(buf->size - buf->use); 496 } 497 498 /** 499 * xmlBufGrow: 500 * @buf: the buffer 501 * @len: the minimum free size to allocate 502 * 503 * Grow the available space of an XML buffer, @len is the target value 504 * This is been kept compatible with xmlBufferGrow() as much as possible 505 * 506 * Returns -1 in case of error or the length made available otherwise 507 */ 508 int 509 xmlBufGrow(xmlBufPtr buf, int len) { 510 size_t ret; 511 512 if ((buf == NULL) || (len < 0)) return(-1); 513 if (len == 0) 514 return(0); 515 ret = xmlBufGrowInternal(buf, len); 516 if (buf->error != 0) 517 return(-1); 518 return((int) ret); 519 } 520 521 /** 522 * xmlBufInflate: 523 * @buf: the buffer 524 * @len: the minimum extra free size to allocate 525 * 526 * Grow the available space of an XML buffer, adding at least @len bytes 527 * 528 * Returns 0 if successful or -1 in case of error 529 */ 530 int 531 xmlBufInflate(xmlBufPtr buf, size_t len) { 532 if (buf == NULL) return(-1); 533 xmlBufGrowInternal(buf, len + buf->size); 534 if (buf->error) 535 return(-1); 536 return(0); 537 } 538 539 /** 540 * xmlBufDump: 541 * @file: the file output 542 * @buf: the buffer to dump 543 * 544 * Dumps an XML buffer to a FILE *. 545 * Returns the number of #xmlChar written 546 */ 547 size_t 548 xmlBufDump(FILE *file, xmlBufPtr buf) { 549 size_t ret; 550 551 if ((buf == NULL) || (buf->error != 0)) { 552 #ifdef DEBUG_BUFFER 553 xmlGenericError(xmlGenericErrorContext, 554 "xmlBufDump: buf == NULL or in error\n"); 555 #endif 556 return(0); 557 } 558 if (buf->content == NULL) { 559 #ifdef DEBUG_BUFFER 560 xmlGenericError(xmlGenericErrorContext, 561 "xmlBufDump: buf->content == NULL\n"); 562 #endif 563 return(0); 564 } 565 CHECK_COMPAT(buf) 566 if (file == NULL) 567 file = stdout; 568 ret = fwrite(buf->content, sizeof(xmlChar), buf->use, file); 569 return(ret); 570 } 571 572 /** 573 * xmlBufContent: 574 * @buf: the buffer 575 * 576 * Function to extract the content of a buffer 577 * 578 * Returns the internal content 579 */ 580 581 xmlChar * 582 xmlBufContent(const xmlBuf *buf) 583 { 584 if ((!buf) || (buf->error)) 585 return NULL; 586 587 return(buf->content); 588 } 589 590 /** 591 * xmlBufEnd: 592 * @buf: the buffer 593 * 594 * Function to extract the end of the content of a buffer 595 * 596 * Returns the end of the internal content or NULL in case of error 597 */ 598 599 xmlChar * 600 xmlBufEnd(xmlBufPtr buf) 601 { 602 if ((!buf) || (buf->error)) 603 return NULL; 604 CHECK_COMPAT(buf) 605 606 return(&buf->content[buf->use]); 607 } 608 609 /** 610 * xmlBufAddLen: 611 * @buf: the buffer 612 * @len: the size which were added at the end 613 * 614 * Sometime data may be added at the end of the buffer without 615 * using the xmlBuf APIs that is used to expand the used space 616 * and set the zero terminating at the end of the buffer 617 * 618 * Returns -1 in case of error and 0 otherwise 619 */ 620 int 621 xmlBufAddLen(xmlBufPtr buf, size_t len) { 622 if ((buf == NULL) || (buf->error)) 623 return(-1); 624 CHECK_COMPAT(buf) 625 if (len > (buf->size - buf->use)) 626 return(-1); 627 buf->use += len; 628 UPDATE_COMPAT(buf) 629 if (buf->size > buf->use) 630 buf->content[buf->use] = 0; 631 else 632 return(-1); 633 return(0); 634 } 635 636 /** 637 * xmlBufErase: 638 * @buf: the buffer 639 * @len: the size to erase at the end 640 * 641 * Sometime data need to be erased at the end of the buffer 642 * 643 * Returns -1 in case of error and 0 otherwise 644 */ 645 int 646 xmlBufErase(xmlBufPtr buf, size_t len) { 647 if ((buf == NULL) || (buf->error)) 648 return(-1); 649 CHECK_COMPAT(buf) 650 if (len > buf->use) 651 return(-1); 652 buf->use -= len; 653 buf->content[buf->use] = 0; 654 UPDATE_COMPAT(buf) 655 return(0); 656 } 657 658 /** 659 * xmlBufLength: 660 * @buf: the buffer 661 * 662 * Function to get the length of a buffer 663 * 664 * Returns the length of data in the internal content 665 */ 666 667 size_t 668 xmlBufLength(const xmlBufPtr buf) 669 { 670 if ((!buf) || (buf->error)) 671 return 0; 672 CHECK_COMPAT(buf) 673 674 return(buf->use); 675 } 676 677 /** 678 * xmlBufUse: 679 * @buf: the buffer 680 * 681 * Function to get the length of a buffer 682 * 683 * Returns the length of data in the internal content 684 */ 685 686 size_t 687 xmlBufUse(const xmlBufPtr buf) 688 { 689 if ((!buf) || (buf->error)) 690 return 0; 691 CHECK_COMPAT(buf) 692 693 return(buf->use); 694 } 695 696 /** 697 * xmlBufAvail: 698 * @buf: the buffer 699 * 700 * Function to find how much free space is allocated but not 701 * used in the buffer. It does not account for the terminating zero 702 * usually needed 703 * 704 * Returns the amount or 0 if none or an error occurred 705 */ 706 707 size_t 708 xmlBufAvail(const xmlBufPtr buf) 709 { 710 if ((!buf) || (buf->error)) 711 return 0; 712 CHECK_COMPAT(buf) 713 714 return(buf->size - buf->use); 715 } 716 717 /** 718 * xmlBufIsEmpty: 719 * @buf: the buffer 720 * 721 * Tell if a buffer is empty 722 * 723 * Returns 0 if no, 1 if yes and -1 in case of error 724 */ 725 int 726 xmlBufIsEmpty(const xmlBufPtr buf) 727 { 728 if ((!buf) || (buf->error)) 729 return(-1); 730 CHECK_COMPAT(buf) 731 732 return(buf->use == 0); 733 } 734 735 /** 736 * xmlBufResize: 737 * @buf: the buffer to resize 738 * @size: the desired size 739 * 740 * Resize a buffer to accommodate minimum size of @size. 741 * 742 * Returns 0 in case of problems, 1 otherwise 743 */ 744 int 745 xmlBufResize(xmlBufPtr buf, size_t size) 746 { 747 unsigned int newSize; 748 xmlChar* rebuf = NULL; 749 size_t start_buf; 750 751 if ((buf == NULL) || (buf->error)) 752 return(0); 753 CHECK_COMPAT(buf) 754 755 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0); 756 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) { 757 /* 758 * Used to provide parsing limits 759 */ 760 if (size >= XML_MAX_TEXT_LENGTH) { 761 xmlBufMemoryError(buf, "buffer error: text too long\n"); 762 return(0); 763 } 764 } 765 766 /* Don't resize if we don't have to */ 767 if (size < buf->size) 768 return 1; 769 770 /* figure out new size */ 771 switch (buf->alloc){ 772 case XML_BUFFER_ALLOC_IO: 773 case XML_BUFFER_ALLOC_DOUBLEIT: 774 /*take care of empty case*/ 775 newSize = (buf->size ? buf->size*2 : size + 10); 776 while (size > newSize) { 777 if (newSize > UINT_MAX / 2) { 778 xmlBufMemoryError(buf, "growing buffer"); 779 return 0; 780 } 781 newSize *= 2; 782 } 783 break; 784 case XML_BUFFER_ALLOC_EXACT: 785 newSize = size+10; 786 break; 787 case XML_BUFFER_ALLOC_HYBRID: 788 if (buf->use < BASE_BUFFER_SIZE) 789 newSize = size; 790 else { 791 newSize = buf->size * 2; 792 while (size > newSize) { 793 if (newSize > UINT_MAX / 2) { 794 xmlBufMemoryError(buf, "growing buffer"); 795 return 0; 796 } 797 newSize *= 2; 798 } 799 } 800 break; 801 802 default: 803 newSize = size+10; 804 break; 805 } 806 807 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { 808 start_buf = buf->content - buf->contentIO; 809 810 if (start_buf > newSize) { 811 /* move data back to start */ 812 memmove(buf->contentIO, buf->content, buf->use); 813 buf->content = buf->contentIO; 814 buf->content[buf->use] = 0; 815 buf->size += start_buf; 816 } else { 817 rebuf = (xmlChar *) xmlRealloc(buf->contentIO, start_buf + newSize); 818 if (rebuf == NULL) { 819 xmlBufMemoryError(buf, "growing buffer"); 820 return 0; 821 } 822 buf->contentIO = rebuf; 823 buf->content = rebuf + start_buf; 824 } 825 } else { 826 if (buf->content == NULL) { 827 rebuf = (xmlChar *) xmlMallocAtomic(newSize); 828 } else if (buf->size - buf->use < 100) { 829 rebuf = (xmlChar *) xmlRealloc(buf->content, newSize); 830 } else { 831 /* 832 * if we are reallocating a buffer far from being full, it's 833 * better to make a new allocation and copy only the used range 834 * and free the old one. 835 */ 836 rebuf = (xmlChar *) xmlMallocAtomic(newSize); 837 if (rebuf != NULL) { 838 memcpy(rebuf, buf->content, buf->use); 839 xmlFree(buf->content); 840 rebuf[buf->use] = 0; 841 } 842 } 843 if (rebuf == NULL) { 844 xmlBufMemoryError(buf, "growing buffer"); 845 return 0; 846 } 847 buf->content = rebuf; 848 } 849 buf->size = newSize; 850 UPDATE_COMPAT(buf) 851 852 return 1; 853 } 854 855 /** 856 * xmlBufAdd: 857 * @buf: the buffer to dump 858 * @str: the #xmlChar string 859 * @len: the number of #xmlChar to add 860 * 861 * Add a string range to an XML buffer. if len == -1, the length of 862 * str is recomputed. 863 * 864 * Returns 0 successful, a positive error code number otherwise 865 * and -1 in case of internal or API error. 866 */ 867 int 868 xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) { 869 unsigned int needSize; 870 871 if ((str == NULL) || (buf == NULL) || (buf->error)) 872 return -1; 873 CHECK_COMPAT(buf) 874 875 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; 876 if (len < -1) { 877 #ifdef DEBUG_BUFFER 878 xmlGenericError(xmlGenericErrorContext, 879 "xmlBufAdd: len < 0\n"); 880 #endif 881 return -1; 882 } 883 if (len == 0) return 0; 884 885 if (len < 0) 886 len = xmlStrlen(str); 887 888 if (len < 0) return -1; 889 if (len == 0) return 0; 890 891 needSize = buf->use + len + 2; 892 if (needSize > buf->size){ 893 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) { 894 /* 895 * Used to provide parsing limits 896 */ 897 if (needSize >= XML_MAX_TEXT_LENGTH) { 898 xmlBufMemoryError(buf, "buffer error: text too long\n"); 899 return(-1); 900 } 901 } 902 if (!xmlBufResize(buf, needSize)){ 903 xmlBufMemoryError(buf, "growing buffer"); 904 return XML_ERR_NO_MEMORY; 905 } 906 } 907 908 memmove(&buf->content[buf->use], str, len*sizeof(xmlChar)); 909 buf->use += len; 910 buf->content[buf->use] = 0; 911 UPDATE_COMPAT(buf) 912 return 0; 913 } 914 915 /** 916 * xmlBufAddHead: 917 * @buf: the buffer 918 * @str: the #xmlChar string 919 * @len: the number of #xmlChar to add 920 * 921 * Add a string range to the beginning of an XML buffer. 922 * if len == -1, the length of @str is recomputed. 923 * 924 * Returns 0 successful, a positive error code number otherwise 925 * and -1 in case of internal or API error. 926 */ 927 int 928 xmlBufAddHead(xmlBufPtr buf, const xmlChar *str, int len) { 929 unsigned int needSize; 930 931 if ((buf == NULL) || (buf->error)) 932 return(-1); 933 CHECK_COMPAT(buf) 934 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; 935 if (str == NULL) { 936 #ifdef DEBUG_BUFFER 937 xmlGenericError(xmlGenericErrorContext, 938 "xmlBufAddHead: str == NULL\n"); 939 #endif 940 return -1; 941 } 942 if (len < -1) { 943 #ifdef DEBUG_BUFFER 944 xmlGenericError(xmlGenericErrorContext, 945 "xmlBufAddHead: len < 0\n"); 946 #endif 947 return -1; 948 } 949 if (len == 0) return 0; 950 951 if (len < 0) 952 len = xmlStrlen(str); 953 954 if (len <= 0) return -1; 955 956 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { 957 size_t start_buf = buf->content - buf->contentIO; 958 959 if (start_buf > (unsigned int) len) { 960 /* 961 * We can add it in the space previously shrinked 962 */ 963 buf->content -= len; 964 memmove(&buf->content[0], str, len); 965 buf->use += len; 966 buf->size += len; 967 UPDATE_COMPAT(buf) 968 return(0); 969 } 970 } 971 needSize = buf->use + len + 2; 972 if (needSize > buf->size){ 973 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) { 974 /* 975 * Used to provide parsing limits 976 */ 977 if (needSize >= XML_MAX_TEXT_LENGTH) { 978 xmlBufMemoryError(buf, "buffer error: text too long\n"); 979 return(-1); 980 } 981 } 982 if (!xmlBufResize(buf, needSize)){ 983 xmlBufMemoryError(buf, "growing buffer"); 984 return XML_ERR_NO_MEMORY; 985 } 986 } 987 988 memmove(&buf->content[len], &buf->content[0], buf->use); 989 memmove(&buf->content[0], str, len); 990 buf->use += len; 991 buf->content[buf->use] = 0; 992 UPDATE_COMPAT(buf) 993 return 0; 994 } 995 996 /** 997 * xmlBufCat: 998 * @buf: the buffer to add to 999 * @str: the #xmlChar string 1000 * 1001 * Append a zero terminated string to an XML buffer. 1002 * 1003 * Returns 0 successful, a positive error code number otherwise 1004 * and -1 in case of internal or API error. 1005 */ 1006 int 1007 xmlBufCat(xmlBufPtr buf, const xmlChar *str) { 1008 if ((buf == NULL) || (buf->error)) 1009 return(-1); 1010 CHECK_COMPAT(buf) 1011 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; 1012 if (str == NULL) return -1; 1013 return xmlBufAdd(buf, str, -1); 1014 } 1015 1016 /** 1017 * xmlBufCCat: 1018 * @buf: the buffer to dump 1019 * @str: the C char string 1020 * 1021 * Append a zero terminated C string to an XML buffer. 1022 * 1023 * Returns 0 successful, a positive error code number otherwise 1024 * and -1 in case of internal or API error. 1025 */ 1026 int 1027 xmlBufCCat(xmlBufPtr buf, const char *str) { 1028 const char *cur; 1029 1030 if ((buf == NULL) || (buf->error)) 1031 return(-1); 1032 CHECK_COMPAT(buf) 1033 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; 1034 if (str == NULL) { 1035 #ifdef DEBUG_BUFFER 1036 xmlGenericError(xmlGenericErrorContext, 1037 "xmlBufCCat: str == NULL\n"); 1038 #endif 1039 return -1; 1040 } 1041 for (cur = str;*cur != 0;cur++) { 1042 if (buf->use + 10 >= buf->size) { 1043 if (!xmlBufResize(buf, buf->use+10)){ 1044 xmlBufMemoryError(buf, "growing buffer"); 1045 return XML_ERR_NO_MEMORY; 1046 } 1047 } 1048 buf->content[buf->use++] = *cur; 1049 } 1050 buf->content[buf->use] = 0; 1051 UPDATE_COMPAT(buf) 1052 return 0; 1053 } 1054 1055 /** 1056 * xmlBufWriteCHAR: 1057 * @buf: the XML buffer 1058 * @string: the string to add 1059 * 1060 * routine which manages and grows an output buffer. This one adds 1061 * xmlChars at the end of the buffer. 1062 * 1063 * Returns 0 if successful, a positive error code number otherwise 1064 * and -1 in case of internal or API error. 1065 */ 1066 int 1067 xmlBufWriteCHAR(xmlBufPtr buf, const xmlChar *string) { 1068 if ((buf == NULL) || (buf->error)) 1069 return(-1); 1070 CHECK_COMPAT(buf) 1071 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) 1072 return(-1); 1073 return(xmlBufCat(buf, string)); 1074 } 1075 1076 /** 1077 * xmlBufWriteChar: 1078 * @buf: the XML buffer output 1079 * @string: the string to add 1080 * 1081 * routine which manage and grows an output buffer. This one add 1082 * C chars at the end of the array. 1083 * 1084 * Returns 0 if successful, a positive error code number otherwise 1085 * and -1 in case of internal or API error. 1086 */ 1087 int 1088 xmlBufWriteChar(xmlBufPtr buf, const char *string) { 1089 if ((buf == NULL) || (buf->error)) 1090 return(-1); 1091 CHECK_COMPAT(buf) 1092 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) 1093 return(-1); 1094 return(xmlBufCCat(buf, string)); 1095 } 1096 1097 1098 /** 1099 * xmlBufWriteQuotedString: 1100 * @buf: the XML buffer output 1101 * @string: the string to add 1102 * 1103 * routine which manage and grows an output buffer. This one writes 1104 * a quoted or double quoted #xmlChar string, checking first if it holds 1105 * quote or double-quotes internally 1106 * 1107 * Returns 0 if successful, a positive error code number otherwise 1108 * and -1 in case of internal or API error. 1109 */ 1110 int 1111 xmlBufWriteQuotedString(xmlBufPtr buf, const xmlChar *string) { 1112 const xmlChar *cur, *base; 1113 if ((buf == NULL) || (buf->error)) 1114 return(-1); 1115 CHECK_COMPAT(buf) 1116 if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) 1117 return(-1); 1118 if (xmlStrchr(string, '\"')) { 1119 if (xmlStrchr(string, '\'')) { 1120 #ifdef DEBUG_BUFFER 1121 xmlGenericError(xmlGenericErrorContext, 1122 "xmlBufWriteQuotedString: string contains quote and double-quotes !\n"); 1123 #endif 1124 xmlBufCCat(buf, "\""); 1125 base = cur = string; 1126 while(*cur != 0){ 1127 if(*cur == '"'){ 1128 if (base != cur) 1129 xmlBufAdd(buf, base, cur - base); 1130 xmlBufAdd(buf, BAD_CAST """, 6); 1131 cur++; 1132 base = cur; 1133 } 1134 else { 1135 cur++; 1136 } 1137 } 1138 if (base != cur) 1139 xmlBufAdd(buf, base, cur - base); 1140 xmlBufCCat(buf, "\""); 1141 } 1142 else{ 1143 xmlBufCCat(buf, "\'"); 1144 xmlBufCat(buf, string); 1145 xmlBufCCat(buf, "\'"); 1146 } 1147 } else { 1148 xmlBufCCat(buf, "\""); 1149 xmlBufCat(buf, string); 1150 xmlBufCCat(buf, "\""); 1151 } 1152 return(0); 1153 } 1154 1155 /** 1156 * xmlBufFromBuffer: 1157 * @buffer: incoming old buffer to convert to a new one 1158 * 1159 * Helper routine to switch from the old buffer structures in use 1160 * in various APIs. It creates a wrapper xmlBufPtr which will be 1161 * used for internal processing until the xmlBufBackToBuffer() is 1162 * issued. 1163 * 1164 * Returns a new xmlBufPtr unless the call failed and NULL is returned 1165 */ 1166 xmlBufPtr 1167 xmlBufFromBuffer(xmlBufferPtr buffer) { 1168 xmlBufPtr ret; 1169 1170 if (buffer == NULL) 1171 return(NULL); 1172 1173 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); 1174 if (ret == NULL) { 1175 xmlBufMemoryError(NULL, "creating buffer"); 1176 return(NULL); 1177 } 1178 ret->use = buffer->use; 1179 ret->size = buffer->size; 1180 ret->compat_use = buffer->use; 1181 ret->compat_size = buffer->size; 1182 ret->error = 0; 1183 ret->buffer = buffer; 1184 ret->alloc = buffer->alloc; 1185 ret->content = buffer->content; 1186 ret->contentIO = buffer->contentIO; 1187 1188 return(ret); 1189 } 1190 1191 /** 1192 * xmlBufBackToBuffer: 1193 * @buf: new buffer wrapping the old one 1194 * 1195 * Function to be called once internal processing had been done to 1196 * update back the buffer provided by the user. This can lead to 1197 * a failure in case the size accumulated in the xmlBuf is larger 1198 * than what an xmlBuffer can support on 64 bits (INT_MAX) 1199 * The xmlBufPtr @buf wrapper is deallocated by this call in any case. 1200 * 1201 * Returns the old xmlBufferPtr unless the call failed and NULL is returned 1202 */ 1203 xmlBufferPtr 1204 xmlBufBackToBuffer(xmlBufPtr buf) { 1205 xmlBufferPtr ret; 1206 1207 if ((buf == NULL) || (buf->error)) 1208 return(NULL); 1209 CHECK_COMPAT(buf) 1210 if (buf->buffer == NULL) { 1211 xmlBufFree(buf); 1212 return(NULL); 1213 } 1214 1215 ret = buf->buffer; 1216 /* 1217 * What to do in case of error in the buffer ??? 1218 */ 1219 if (buf->use > INT_MAX) { 1220 /* 1221 * Worse case, we really allocated and used more than the 1222 * maximum allowed memory for an xmlBuffer on this architecture. 1223 * Keep the buffer but provide a truncated size value. 1224 */ 1225 xmlBufOverflowError(buf, "Used size too big for xmlBuffer"); 1226 ret->use = INT_MAX; 1227 ret->size = INT_MAX; 1228 } else if (buf->size > INT_MAX) { 1229 /* 1230 * milder case, we allocated more than the maximum allowed memory 1231 * for an xmlBuffer on this architecture, but used less than the 1232 * limit. 1233 * Keep the buffer but provide a truncated size value. 1234 */ 1235 xmlBufOverflowError(buf, "Allocated size too big for xmlBuffer"); 1236 ret->size = INT_MAX; 1237 } 1238 ret->use = (int) buf->use; 1239 ret->size = (int) buf->size; 1240 ret->alloc = buf->alloc; 1241 ret->content = buf->content; 1242 ret->contentIO = buf->contentIO; 1243 xmlFree(buf); 1244 return(ret); 1245 } 1246 1247 /** 1248 * xmlBufMergeBuffer: 1249 * @buf: an xmlBufPtr 1250 * @buffer: the buffer to consume into @buf 1251 * 1252 * The content of @buffer is appended to @buf and @buffer is freed 1253 * 1254 * Returns -1 in case of error, 0 otherwise, in any case @buffer is freed 1255 */ 1256 int 1257 xmlBufMergeBuffer(xmlBufPtr buf, xmlBufferPtr buffer) { 1258 int ret = 0; 1259 1260 if ((buf == NULL) || (buf->error)) { 1261 xmlBufferFree(buffer); 1262 return(-1); 1263 } 1264 CHECK_COMPAT(buf) 1265 if ((buffer != NULL) && (buffer->content != NULL) && 1266 (buffer->use > 0)) { 1267 ret = xmlBufAdd(buf, buffer->content, buffer->use); 1268 } 1269 xmlBufferFree(buffer); 1270 return(ret); 1271 } 1272 1273 /** 1274 * xmlBufResetInput: 1275 * @buf: an xmlBufPtr 1276 * @input: an xmlParserInputPtr 1277 * 1278 * Update the input to use the current set of pointers from the buffer. 1279 * 1280 * Returns -1 in case of error, 0 otherwise 1281 */ 1282 int 1283 xmlBufResetInput(xmlBufPtr buf, xmlParserInputPtr input) { 1284 if ((input == NULL) || (buf == NULL) || (buf->error)) 1285 return(-1); 1286 CHECK_COMPAT(buf) 1287 input->base = input->cur = buf->content; 1288 input->end = &buf->content[buf->use]; 1289 return(0); 1290 } 1291 1292 /** 1293 * xmlBufGetInputBase: 1294 * @buf: an xmlBufPtr 1295 * @input: an xmlParserInputPtr 1296 * 1297 * Get the base of the @input relative to the beginning of the buffer 1298 * 1299 * Returns the size_t corresponding to the displacement 1300 */ 1301 size_t 1302 xmlBufGetInputBase(xmlBufPtr buf, xmlParserInputPtr input) { 1303 size_t base; 1304 1305 if ((input == NULL) || (buf == NULL) || (buf->error)) 1306 return(-1); 1307 CHECK_COMPAT(buf) 1308 base = input->base - buf->content; 1309 /* 1310 * We could do some pointer arythmetic checks but that's probably 1311 * sufficient. 1312 */ 1313 if (base > buf->size) { 1314 xmlBufOverflowError(buf, "Input reference outside of the buffer"); 1315 base = 0; 1316 } 1317 return(base); 1318 } 1319 1320 /** 1321 * xmlBufSetInputBaseCur: 1322 * @buf: an xmlBufPtr 1323 * @input: an xmlParserInputPtr 1324 * @base: the base value relative to the beginning of the buffer 1325 * @cur: the cur value relative to the beginning of the buffer 1326 * 1327 * Update the input to use the base and cur relative to the buffer 1328 * after a possible reallocation of its content 1329 * 1330 * Returns -1 in case of error, 0 otherwise 1331 */ 1332 int 1333 xmlBufSetInputBaseCur(xmlBufPtr buf, xmlParserInputPtr input, 1334 size_t base, size_t cur) { 1335 if ((input == NULL) || (buf == NULL) || (buf->error)) 1336 return(-1); 1337 CHECK_COMPAT(buf) 1338 input->base = &buf->content[base]; 1339 input->cur = input->base + cur; 1340 input->end = &buf->content[buf->use]; 1341 return(0); 1342 } 1343 1344 #define bottom_buf 1345 #include "elfgcchack.h" 1346
