1 /*
2 * buf.c: memory buffers for libxml2
3 *
4 * new buffer structures and entry points to simplify the maintenance
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@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 information
87 *
88 * Handle an out of memory condition
89 * To be improved...
90 */
91 static void
xmlBufMemoryError(xmlBufPtr buf,const char * extra)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 information
102 *
103 * Handle a buffer overflow error
104 * To be improved...
105 */
106 static void
xmlBufOverflowError(xmlBufPtr buf,const char * extra)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
xmlBufCreate(void)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
xmlBufCreateSize(size_t size)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 *
xmlBufDetach(xmlBufPtr buf)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
xmlBufCreateStatic(void * mem,size_t size)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
xmlBufGetAllocationScheme(xmlBufPtr buf)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
xmlBufSetAllocationScheme(xmlBufPtr buf,xmlBufferAllocationScheme scheme)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
xmlBufFree(xmlBufPtr buf)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
xmlBufEmpty(xmlBufPtr buf)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
xmlBufShrink(xmlBufPtr buf,size_t len)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 shrunk 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
xmlBufGrowInternal(xmlBufPtr buf,size_t len)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
xmlBufGrow(xmlBufPtr buf,int len)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
xmlBufInflate(xmlBufPtr buf,size_t len)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
xmlBufDump(FILE * file,xmlBufPtr buf)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 *
xmlBufContent(const xmlBuf * buf)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 *
xmlBufEnd(xmlBufPtr buf)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
xmlBufAddLen(xmlBufPtr buf,size_t len)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
xmlBufErase(xmlBufPtr buf,size_t len)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
xmlBufLength(const xmlBufPtr buf)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
xmlBufUse(const xmlBufPtr buf)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
xmlBufAvail(const xmlBufPtr buf)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
xmlBufIsEmpty(const xmlBufPtr buf)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
xmlBufResize(xmlBufPtr buf,size_t size)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
xmlBufAdd(xmlBufPtr buf,const xmlChar * str,int len)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
xmlBufAddHead(xmlBufPtr buf,const xmlChar * str,int len)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 shrunk
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
xmlBufCat(xmlBufPtr buf,const xmlChar * str)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
xmlBufCCat(xmlBufPtr buf,const char * str)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
xmlBufWriteCHAR(xmlBufPtr buf,const xmlChar * string)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
xmlBufWriteChar(xmlBufPtr buf,const char * string)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
xmlBufWriteQuotedString(xmlBufPtr buf,const xmlChar * string)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
xmlBufFromBuffer(xmlBufferPtr buffer)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
xmlBufBackToBuffer(xmlBufPtr buf)1204 xmlBufBackToBuffer(xmlBufPtr buf) {
1205 xmlBufferPtr ret;
1206
1207 if (buf == NULL)
1208 return(NULL);
1209 CHECK_COMPAT(buf)
1210 if ((buf->error) || (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->use = (int) buf->use;
1237 ret->size = INT_MAX;
1238 } else {
1239 ret->use = (int) buf->use;
1240 ret->size = (int) buf->size;
1241 }
1242 ret->alloc = buf->alloc;
1243 ret->content = buf->content;
1244 ret->contentIO = buf->contentIO;
1245 xmlFree(buf);
1246 return(ret);
1247 }
1248
1249 /**
1250 * xmlBufMergeBuffer:
1251 * @buf: an xmlBufPtr
1252 * @buffer: the buffer to consume into @buf
1253 *
1254 * The content of @buffer is appended to @buf and @buffer is freed
1255 *
1256 * Returns -1 in case of error, 0 otherwise, in any case @buffer is freed
1257 */
1258 int
xmlBufMergeBuffer(xmlBufPtr buf,xmlBufferPtr buffer)1259 xmlBufMergeBuffer(xmlBufPtr buf, xmlBufferPtr buffer) {
1260 int ret = 0;
1261
1262 if ((buf == NULL) || (buf->error)) {
1263 xmlBufferFree(buffer);
1264 return(-1);
1265 }
1266 CHECK_COMPAT(buf)
1267 if ((buffer != NULL) && (buffer->content != NULL) &&
1268 (buffer->use > 0)) {
1269 ret = xmlBufAdd(buf, buffer->content, buffer->use);
1270 }
1271 xmlBufferFree(buffer);
1272 return(ret);
1273 }
1274
1275 /**
1276 * xmlBufResetInput:
1277 * @buf: an xmlBufPtr
1278 * @input: an xmlParserInputPtr
1279 *
1280 * Update the input to use the current set of pointers from the buffer.
1281 *
1282 * Returns -1 in case of error, 0 otherwise
1283 */
1284 int
xmlBufResetInput(xmlBufPtr buf,xmlParserInputPtr input)1285 xmlBufResetInput(xmlBufPtr buf, xmlParserInputPtr input) {
1286 if ((input == NULL) || (buf == NULL) || (buf->error))
1287 return(-1);
1288 CHECK_COMPAT(buf)
1289 input->base = input->cur = buf->content;
1290 input->end = &buf->content[buf->use];
1291 return(0);
1292 }
1293
1294 /**
1295 * xmlBufGetInputBase:
1296 * @buf: an xmlBufPtr
1297 * @input: an xmlParserInputPtr
1298 *
1299 * Get the base of the @input relative to the beginning of the buffer
1300 *
1301 * Returns the size_t corresponding to the displacement
1302 */
1303 size_t
xmlBufGetInputBase(xmlBufPtr buf,xmlParserInputPtr input)1304 xmlBufGetInputBase(xmlBufPtr buf, xmlParserInputPtr input) {
1305 size_t base;
1306
1307 if ((input == NULL) || (buf == NULL) || (buf->error))
1308 return(-1);
1309 CHECK_COMPAT(buf)
1310 base = input->base - buf->content;
1311 /*
1312 * We could do some pointer arithmetic checks but that's probably
1313 * sufficient.
1314 */
1315 if (base > buf->size) {
1316 xmlBufOverflowError(buf, "Input reference outside of the buffer");
1317 base = 0;
1318 }
1319 return(base);
1320 }
1321
1322 /**
1323 * xmlBufSetInputBaseCur:
1324 * @buf: an xmlBufPtr
1325 * @input: an xmlParserInputPtr
1326 * @base: the base value relative to the beginning of the buffer
1327 * @cur: the cur value relative to the beginning of the buffer
1328 *
1329 * Update the input to use the base and cur relative to the buffer
1330 * after a possible reallocation of its content
1331 *
1332 * Returns -1 in case of error, 0 otherwise
1333 */
1334 int
xmlBufSetInputBaseCur(xmlBufPtr buf,xmlParserInputPtr input,size_t base,size_t cur)1335 xmlBufSetInputBaseCur(xmlBufPtr buf, xmlParserInputPtr input,
1336 size_t base, size_t cur) {
1337 if (input == NULL)
1338 return(-1);
1339 if ((buf == NULL) || (buf->error)) {
1340 input->base = input->cur = input->end = BAD_CAST "";
1341 return(-1);
1342 }
1343 CHECK_COMPAT(buf)
1344 input->base = &buf->content[base];
1345 input->cur = input->base + cur;
1346 input->end = &buf->content[buf->use];
1347 return(0);
1348 }
1349
1350 #define bottom_buf
1351 #include "elfgcchack.h"
1352