2 /* pngerror.c - stub functions for i/o and memory allocation
4 * Last changed in libpng 1.5.8 [February 1, 2011]
5 * Copyright (c) 1998-2012 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
13 * This file provides a location for all error handling. Users who
14 * need special error handling are expected to write replacement functions
15 * and use png_set_error_fn() to use those functions. See the instructions
21 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
23 static PNG_FUNCTION(void, png_default_error,PNGARG((png_structp png_ptr,
24 png_const_charp error_message)),PNG_NORETURN);
26 #ifdef PNG_WARNINGS_SUPPORTED
27 static void /* PRIVATE */
28 png_default_warning PNGARG((png_structp png_ptr,
29 png_const_charp warning_message));
30 #endif /* PNG_WARNINGS_SUPPORTED */
32 /* This function is called whenever there is a fatal error. This function
33 * should not be changed. If there is a need to handle errors differently,
34 * you should supply a replacement error function and use png_set_error_fn()
35 * to replace the error function at run-time.
37 #ifdef PNG_ERROR_TEXT_SUPPORTED
38 PNG_FUNCTION(void,PNGAPI
39 png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
41 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
46 (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
48 if (*error_message == PNG_LITERAL_SHARP)
50 /* Strip "#nnnn " from beginning of error message. */
52 for (offset = 1; offset<15; offset++)
53 if (error_message[offset] == ' ')
56 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
59 for (i = 0; i < offset - 1; i++)
60 msg[i] = error_message[i + 1];
66 error_message += offset;
71 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
81 if (png_ptr != NULL && png_ptr->error_fn != NULL)
82 (*(png_ptr->error_fn))(png_ptr, error_message);
84 /* If the custom handler doesn't exist, or if it returns,
85 use the default handler, which will not return. */
86 png_default_error(png_ptr, error_message);
89 PNG_FUNCTION(void,PNGAPI
90 png_err,(png_structp png_ptr),PNG_NORETURN)
92 /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
93 * erroneously as '\0', instead of the empty string "". This was
94 * apparently an error, introduced in libpng-1.2.20, and png_default_error
95 * will crash in this case.
97 if (png_ptr != NULL && png_ptr->error_fn != NULL)
98 (*(png_ptr->error_fn))(png_ptr, "");
100 /* If the custom handler doesn't exist, or if it returns,
101 use the default handler, which will not return. */
102 png_default_error(png_ptr, "");
104 #endif /* PNG_ERROR_TEXT_SUPPORTED */
106 /* Utility to safely appends strings to a buffer. This never errors out so
107 * error checking is not required in the caller.
110 png_safecat(png_charp buffer, size_t bufsize, size_t pos,
111 png_const_charp string)
113 if (buffer != NULL && pos < bufsize)
116 while (*string != '\0' && pos < bufsize-1)
117 buffer[pos++] = *string++;
125 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
126 /* Utility to dump an unsigned value into a buffer, given a start pointer and
127 * and end pointer (which should point just *beyond* the end of the buffer!)
128 * Returns the pointer to the start of the formatted string.
131 png_format_number(png_const_charp start, png_charp end, int format,
132 png_alloc_size_t number)
134 int count = 0; /* number of digits output */
135 int mincount = 1; /* minimum number required */
136 int output = 0; /* digit output (for the fixed point format) */
140 /* This is written so that the loop always runs at least once, even with
143 while (end > start && (number != 0 || count < mincount))
146 static const char digits[] = "0123456789ABCDEF";
150 case PNG_NUMBER_FORMAT_fixed:
151 /* Needs five digits (the fraction) */
153 if (output || number % 10 != 0)
155 *--end = digits[number % 10];
161 case PNG_NUMBER_FORMAT_02u:
162 /* Expects at least 2 digits. */
166 case PNG_NUMBER_FORMAT_u:
167 *--end = digits[number % 10];
171 case PNG_NUMBER_FORMAT_02x:
172 /* This format expects at least two digits */
176 case PNG_NUMBER_FORMAT_x:
177 *--end = digits[number & 0xf];
181 default: /* an error */
186 /* Keep track of the number of digits added */
189 /* Float a fixed number here: */
190 if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
192 /* End of the fraction, but maybe nothing was output? In that case
193 * drop the decimal point. If the number is a true zero handle that
198 else if (number == 0) /* and !output */
207 #ifdef PNG_WARNINGS_SUPPORTED
208 /* This function is called whenever there is a non-fatal error. This function
209 * should not be changed. If there is a need to handle warnings differently,
210 * you should supply a replacement warning function and use
211 * png_set_error_fn() to replace the warning function at run-time.
214 png_warning(png_structp png_ptr, png_const_charp warning_message)
219 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
221 (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
224 if (*warning_message == PNG_LITERAL_SHARP)
226 for (offset = 1; offset < 15; offset++)
227 if (warning_message[offset] == ' ')
232 if (png_ptr != NULL && png_ptr->warning_fn != NULL)
233 (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
235 png_default_warning(png_ptr, warning_message + offset);
238 /* These functions support 'formatted' warning messages with up to
239 * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
240 * is introduced by @<number>, where 'number' starts at 1. This follows the
241 * standard established by X/Open for internationalizable error messages.
244 png_warning_parameter(png_warning_parameters p, int number,
245 png_const_charp string)
247 if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
248 (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
252 png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
253 png_alloc_size_t value)
255 char buffer[PNG_NUMBER_BUFFER_SIZE];
256 png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
260 png_warning_parameter_signed(png_warning_parameters p, int number, int format,
265 char buffer[PNG_NUMBER_BUFFER_SIZE];
267 /* Avoid overflow by doing the negate in a png_alloc_size_t: */
268 u = (png_alloc_size_t)value;
272 str = PNG_FORMAT_NUMBER(buffer, format, u);
274 if (value < 0 && str > buffer)
277 png_warning_parameter(p, number, str);
281 png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
282 png_const_charp message)
284 /* The internal buffer is just 192 bytes - enough for all our messages,
285 * overflow doesn't happen because this code checks! If someone figures
286 * out how to send us a message longer than 192 bytes, all that will
287 * happen is that the message will be truncated appropriately.
289 size_t i = 0; /* Index in the msg[] buffer: */
292 /* Each iteration through the following loop writes at most one character
293 * to msg[i++] then returns here to validate that there is still space for
294 * the trailing '\0'. It may (in the case of a parameter) read more than
295 * one character from message[]; it must check for '\0' and continue to the
296 * test if it finds the end of string.
298 while (i<(sizeof msg)-1 && *message != '\0')
300 /* '@' at end of string is now just printed (previously it was skipped);
301 * it is an error in the calling code to terminate the string with @.
303 if (p != NULL && *message == '@' && message[1] != '\0')
305 int parameter_char = *++message; /* Consume the '@' */
306 static const char valid_parameters[] = "123456789";
309 /* Search for the parameter digit, the index in the string is the
312 while (valid_parameters[parameter] != parameter_char &&
313 valid_parameters[parameter] != '\0')
316 /* If the parameter digit is out of range it will just get printed. */
317 if (parameter < PNG_WARNING_PARAMETER_COUNT)
319 /* Append this parameter */
320 png_const_charp parm = p[parameter];
321 png_const_charp pend = p[parameter] + (sizeof p[parameter]);
323 /* No need to copy the trailing '\0' here, but there is no guarantee
324 * that parm[] has been initialized, so there is no guarantee of a
327 while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
330 /* Consume the parameter digit too: */
335 /* else not a parameter and there is a character after the @ sign; just
336 * copy that. This is known not to be '\0' because of the test above.
340 /* At this point *message can't be '\0', even in the bad parameter case
341 * above where there is a lone '@' at the end of the message string.
343 msg[i++] = *message++;
346 /* i is always less than (sizeof msg), so: */
349 /* And this is the formatted message, it may be larger than
350 * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these are
351 * not (currently) formatted.
353 png_warning(png_ptr, msg);
355 #endif /* PNG_WARNINGS_SUPPORTED */
357 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
359 png_benign_error(png_structp png_ptr, png_const_charp error_message)
361 if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
362 png_warning(png_ptr, error_message);
364 png_error(png_ptr, error_message);
368 /* These utilities are used internally to build an error message that relates
369 * to the current chunk. The chunk name comes from png_ptr->chunk_name,
370 * this is used to prefix the message. The message is limited in length
371 * to 63 bytes, the name characters are output as hex digits wrapped in []
372 * if the character is invalid.
374 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
375 static PNG_CONST char png_digit[16] = {
376 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
377 'A', 'B', 'C', 'D', 'E', 'F'
380 #define PNG_MAX_ERROR_TEXT 64
381 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
382 static void /* PRIVATE */
383 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
386 png_uint_32 chunk_name = png_ptr->chunk_name;
387 int iout = 0, ishift = 24;
391 int c = (int)(chunk_name >> ishift) & 0xff;
396 buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
397 buffer[iout++] = png_digit[(c & 0xf0) >> 4];
398 buffer[iout++] = png_digit[c & 0x0f];
399 buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
404 buffer[iout++] = (char)c;
408 if (error_message == NULL)
415 buffer[iout++] = ':';
416 buffer[iout++] = ' ';
418 while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
419 buffer[iout++] = error_message[iin++];
421 /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
425 #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
427 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
428 PNG_FUNCTION(void,PNGAPI
429 png_chunk_error,(png_structp png_ptr, png_const_charp error_message),
432 char msg[18+PNG_MAX_ERROR_TEXT];
434 png_error(png_ptr, error_message);
438 png_format_buffer(png_ptr, msg, error_message);
439 png_error(png_ptr, msg);
442 #endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
444 #ifdef PNG_WARNINGS_SUPPORTED
446 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
448 char msg[18+PNG_MAX_ERROR_TEXT];
450 png_warning(png_ptr, warning_message);
454 png_format_buffer(png_ptr, msg, warning_message);
455 png_warning(png_ptr, msg);
458 #endif /* PNG_WARNINGS_SUPPORTED */
460 #ifdef PNG_READ_SUPPORTED
461 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
463 png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
465 if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
466 png_chunk_warning(png_ptr, error_message);
469 png_chunk_error(png_ptr, error_message);
472 #endif /* PNG_READ_SUPPORTED */
474 #ifdef PNG_ERROR_TEXT_SUPPORTED
475 #ifdef PNG_FLOATING_POINT_SUPPORTED
477 png_fixed_error,(png_structp png_ptr, png_const_charp name),PNG_NORETURN)
479 # define fixed_message "fixed point overflow in "
480 # define fixed_message_ln ((sizeof fixed_message)-1)
482 char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
483 png_memcpy(msg, fixed_message, fixed_message_ln);
485 if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
487 msg[fixed_message_ln + iin] = name[iin];
490 msg[fixed_message_ln + iin] = 0;
491 png_error(png_ptr, msg);
496 #ifdef PNG_SETJMP_SUPPORTED
497 /* This API only exists if ANSI-C style error handling is used,
498 * otherwise it is necessary for png_default_error to be overridden.
501 png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
504 if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf))
507 png_ptr->longjmp_fn = longjmp_fn;
508 return &png_ptr->longjmp_buffer;
512 /* This is the default error handling function. Note that replacements for
513 * this function MUST NOT RETURN, or the program will likely crash. This
514 * function is used by default, or if the program supplies NULL for the
515 * error function pointer in png_set_error_fn().
517 static PNG_FUNCTION(void /* PRIVATE */,
518 png_default_error,(png_structp png_ptr, png_const_charp error_message),
521 #ifdef PNG_CONSOLE_IO_SUPPORTED
522 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
523 /* Check on NULL only added in 1.5.4 */
524 if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
526 /* Strip "#nnnn " from beginning of error message. */
528 char error_number[16];
529 for (offset = 0; offset<15; offset++)
531 error_number[offset] = error_message[offset + 1];
532 if (error_message[offset] == ' ')
536 if ((offset > 1) && (offset < 15))
538 error_number[offset - 1] = '\0';
539 fprintf(stderr, "libpng error no. %s: %s",
540 error_number, error_message + offset + 1);
541 fprintf(stderr, PNG_STRING_NEWLINE);
546 fprintf(stderr, "libpng error: %s, offset=%d",
547 error_message, offset);
548 fprintf(stderr, PNG_STRING_NEWLINE);
554 fprintf(stderr, "libpng error: %s", error_message ? error_message :
556 fprintf(stderr, PNG_STRING_NEWLINE);
559 PNG_UNUSED(error_message) /* Make compiler happy */
561 png_longjmp(png_ptr, 1);
564 PNG_FUNCTION(void,PNGAPI
565 png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN)
567 #ifdef PNG_SETJMP_SUPPORTED
568 if (png_ptr && png_ptr->longjmp_fn)
570 # ifdef USE_FAR_KEYWORD
573 png_memcpy(tmp_jmpbuf, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
574 png_ptr->longjmp_fn(tmp_jmpbuf, val);
578 png_ptr->longjmp_fn(png_ptr->longjmp_buffer, val);
582 /* Here if not setjmp support or if png_ptr is null. */
586 #ifdef PNG_WARNINGS_SUPPORTED
587 /* This function is called when there is a warning, but the library thinks
588 * it can continue anyway. Replacement functions don't have to do anything
589 * here if you don't want them to. In the default configuration, png_ptr is
590 * not used, but it is passed in case it may be useful.
592 static void /* PRIVATE */
593 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
595 #ifdef PNG_CONSOLE_IO_SUPPORTED
596 # ifdef PNG_ERROR_NUMBERS_SUPPORTED
597 if (*warning_message == PNG_LITERAL_SHARP)
600 char warning_number[16];
601 for (offset = 0; offset < 15; offset++)
603 warning_number[offset] = warning_message[offset + 1];
604 if (warning_message[offset] == ' ')
608 if ((offset > 1) && (offset < 15))
610 warning_number[offset + 1] = '\0';
611 fprintf(stderr, "libpng warning no. %s: %s",
612 warning_number, warning_message + offset);
613 fprintf(stderr, PNG_STRING_NEWLINE);
618 fprintf(stderr, "libpng warning: %s",
620 fprintf(stderr, PNG_STRING_NEWLINE);
627 fprintf(stderr, "libpng warning: %s", warning_message);
628 fprintf(stderr, PNG_STRING_NEWLINE);
631 PNG_UNUSED(warning_message) /* Make compiler happy */
633 PNG_UNUSED(png_ptr) /* Make compiler happy */
635 #endif /* PNG_WARNINGS_SUPPORTED */
637 /* This function is called when the application wants to use another method
638 * of handling errors and warnings. Note that the error function MUST NOT
639 * return to the calling routine or serious problems will occur. The return
640 * method used in the default routine calls longjmp(png_ptr->longjmp_buffer, 1)
643 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
644 png_error_ptr error_fn, png_error_ptr warning_fn)
649 png_ptr->error_ptr = error_ptr;
650 png_ptr->error_fn = error_fn;
651 #ifdef PNG_WARNINGS_SUPPORTED
652 png_ptr->warning_fn = warning_fn;
654 PNG_UNUSED(warning_fn)
659 /* This function returns a pointer to the error_ptr associated with the user
660 * functions. The application should free any memory associated with this
661 * pointer before png_write_destroy and png_read_destroy are called.
664 png_get_error_ptr(png_const_structp png_ptr)
669 return ((png_voidp)png_ptr->error_ptr);
673 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
675 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
680 ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
681 PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
685 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */