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 */