| /* pngerror.c - stub functions for i/o and memory allocation |
| * |
| * Copyright (c) 2018-2024 Cosmin Truta |
| * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson |
| * Copyright (c) 1996-1997 Andreas Dilger |
| * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. |
| * |
| * This code is released under the libpng license. |
| * For conditions of distribution and use, see the disclaimer |
| * and license in png.h |
| * |
| * This file provides a location for all error handling. Users who |
| * need special error handling are expected to write replacement functions |
| * and use png_set_error_fn() to use those functions. See the instructions |
| * at each function. |
| */ |
| |
| #include "pngpriv.h" |
| |
| #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
| |
| static PNG_FUNCTION(void /* PRIVATE */, |
| png_default_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| PNG_NORETURN); |
| |
| #ifdef PNG_WARNINGS_SUPPORTED |
| static void /* PRIVATE */ |
| png_default_warning(png_const_structrp png_ptr, |
| png_const_charp warning_message); |
| #endif /* WARNINGS */ |
| |
| /* This function is called whenever there is a fatal error. This function |
| * should not be changed. If there is a need to handle errors differently, |
| * you should supply a replacement error function and use png_set_error_fn() |
| * to replace the error function at run-time. |
| */ |
| #ifdef PNG_ERROR_TEXT_SUPPORTED |
| PNG_FUNCTION(void,PNGAPI |
| png_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| PNG_NORETURN) |
| { |
| #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| char msg[16]; |
| if (png_ptr != NULL) |
| { |
| if ((png_ptr->flags & |
| (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) |
| { |
| if (*error_message == PNG_LITERAL_SHARP) |
| { |
| /* Strip "#nnnn " from beginning of error message. */ |
| int offset; |
| for (offset = 1; offset<15; offset++) |
| if (error_message[offset] == ' ') |
| break; |
| |
| if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) |
| { |
| int i; |
| for (i = 0; i < offset - 1; i++) |
| msg[i] = error_message[i + 1]; |
| msg[i - 1] = '\0'; |
| error_message = msg; |
| } |
| |
| else |
| error_message += offset; |
| } |
| |
| else |
| { |
| if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) |
| { |
| msg[0] = '0'; |
| msg[1] = '\0'; |
| error_message = msg; |
| } |
| } |
| } |
| } |
| #endif |
| if (png_ptr != NULL && png_ptr->error_fn != NULL) |
| (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), |
| error_message); |
| |
| /* If the custom handler doesn't exist, or if it returns, |
| use the default handler, which will not return. */ |
| png_default_error(png_ptr, error_message); |
| } |
| #else |
| PNG_FUNCTION(void,PNGAPI |
| png_err,(png_const_structrp png_ptr),PNG_NORETURN) |
| { |
| /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed |
| * erroneously as '\0', instead of the empty string "". This was |
| * apparently an error, introduced in libpng-1.2.20, and png_default_error |
| * will crash in this case. |
| */ |
| if (png_ptr != NULL && png_ptr->error_fn != NULL) |
| (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), ""); |
| |
| /* If the custom handler doesn't exist, or if it returns, |
| use the default handler, which will not return. */ |
| png_default_error(png_ptr, ""); |
| } |
| #endif /* ERROR_TEXT */ |
| |
| /* Utility to safely appends strings to a buffer. This never errors out so |
| * error checking is not required in the caller. |
| */ |
| size_t |
| png_safecat(png_charp buffer, size_t bufsize, size_t pos, |
| png_const_charp string) |
| { |
| if (buffer != NULL && pos < bufsize) |
| { |
| if (string != NULL) |
| while (*string != '\0' && pos < bufsize-1) |
| buffer[pos++] = *string++; |
| |
| buffer[pos] = '\0'; |
| } |
| |
| return pos; |
| } |
| |
| #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) |
| /* Utility to dump an unsigned value into a buffer, given a start pointer and |
| * and end pointer (which should point just *beyond* the end of the buffer!) |
| * Returns the pointer to the start of the formatted string. |
| */ |
| png_charp |
| png_format_number(png_const_charp start, png_charp end, int format, |
| png_alloc_size_t number) |
| { |
| int count = 0; /* number of digits output */ |
| int mincount = 1; /* minimum number required */ |
| int output = 0; /* digit output (for the fixed point format) */ |
| |
| *--end = '\0'; |
| |
| /* This is written so that the loop always runs at least once, even with |
| * number zero. |
| */ |
| while (end > start && (number != 0 || count < mincount)) |
| { |
| |
| static const char digits[] = "0123456789ABCDEF"; |
| |
| switch (format) |
| { |
| case PNG_NUMBER_FORMAT_fixed: |
| /* Needs five digits (the fraction) */ |
| mincount = 5; |
| if (output != 0 || number % 10 != 0) |
| { |
| *--end = digits[number % 10]; |
| output = 1; |
| } |
| number /= 10; |
| break; |
| |
| case PNG_NUMBER_FORMAT_02u: |
| /* Expects at least 2 digits. */ |
| mincount = 2; |
| /* FALLTHROUGH */ |
| |
| case PNG_NUMBER_FORMAT_u: |
| *--end = digits[number % 10]; |
| number /= 10; |
| break; |
| |
| case PNG_NUMBER_FORMAT_02x: |
| /* This format expects at least two digits */ |
| mincount = 2; |
| /* FALLTHROUGH */ |
| |
| case PNG_NUMBER_FORMAT_x: |
| *--end = digits[number & 0xf]; |
| number >>= 4; |
| break; |
| |
| default: /* an error */ |
| number = 0; |
| break; |
| } |
| |
| /* Keep track of the number of digits added */ |
| ++count; |
| |
| /* Float a fixed number here: */ |
| if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start)) |
| { |
| /* End of the fraction, but maybe nothing was output? In that case |
| * drop the decimal point. If the number is a true zero handle that |
| * here. |
| */ |
| if (output != 0) |
| *--end = '.'; |
| else if (number == 0) /* and !output */ |
| *--end = '0'; |
| } |
| } |
| |
| return end; |
| } |
| #endif |
| |
| #ifdef PNG_WARNINGS_SUPPORTED |
| /* This function is called whenever there is a non-fatal error. This function |
| * should not be changed. If there is a need to handle warnings differently, |
| * you should supply a replacement warning function and use |
| * png_set_error_fn() to replace the warning function at run-time. |
| */ |
| void PNGAPI |
| png_warning(png_const_structrp png_ptr, png_const_charp warning_message) |
| { |
| int offset = 0; |
| if (png_ptr != NULL) |
| { |
| #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| if ((png_ptr->flags & |
| (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) |
| #endif |
| { |
| if (*warning_message == PNG_LITERAL_SHARP) |
| { |
| for (offset = 1; offset < 15; offset++) |
| if (warning_message[offset] == ' ') |
| break; |
| } |
| } |
| } |
| if (png_ptr != NULL && png_ptr->warning_fn != NULL) |
| (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr), |
| warning_message + offset); |
| else |
| png_default_warning(png_ptr, warning_message + offset); |
| } |
| |
| /* These functions support 'formatted' warning messages with up to |
| * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter |
| * is introduced by @<number>, where 'number' starts at 1. This follows the |
| * standard established by X/Open for internationalizable error messages. |
| */ |
| void |
| png_warning_parameter(png_warning_parameters p, int number, |
| png_const_charp string) |
| { |
| if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT) |
| (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string); |
| } |
| |
| void |
| png_warning_parameter_unsigned(png_warning_parameters p, int number, int format, |
| png_alloc_size_t value) |
| { |
| char buffer[PNG_NUMBER_BUFFER_SIZE] = {0}; |
| png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value)); |
| } |
| |
| void |
| png_warning_parameter_signed(png_warning_parameters p, int number, int format, |
| png_int_32 value) |
| { |
| png_alloc_size_t u; |
| png_charp str; |
| char buffer[PNG_NUMBER_BUFFER_SIZE] = {0}; |
| |
| /* Avoid overflow by doing the negate in a png_alloc_size_t: */ |
| u = (png_alloc_size_t)value; |
| if (value < 0) |
| u = ~u + 1; |
| |
| str = PNG_FORMAT_NUMBER(buffer, format, u); |
| |
| if (value < 0 && str > buffer) |
| *--str = '-'; |
| |
| png_warning_parameter(p, number, str); |
| } |
| |
| void |
| png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p, |
| png_const_charp message) |
| { |
| /* The internal buffer is just 192 bytes - enough for all our messages, |
| * overflow doesn't happen because this code checks! If someone figures |
| * out how to send us a message longer than 192 bytes, all that will |
| * happen is that the message will be truncated appropriately. |
| */ |
| size_t i = 0; /* Index in the msg[] buffer: */ |
| char msg[192]; |
| |
| /* Each iteration through the following loop writes at most one character |
| * to msg[i++] then returns here to validate that there is still space for |
| * the trailing '\0'. It may (in the case of a parameter) read more than |
| * one character from message[]; it must check for '\0' and continue to the |
| * test if it finds the end of string. |
| */ |
| while (i<(sizeof msg)-1 && *message != '\0') |
| { |
| /* '@' at end of string is now just printed (previously it was skipped); |
| * it is an error in the calling code to terminate the string with @. |
| */ |
| if (p != NULL && *message == '@' && message[1] != '\0') |
| { |
| int parameter_char = *++message; /* Consume the '@' */ |
| static const char valid_parameters[] = "123456789"; |
| int parameter = 0; |
| |
| /* Search for the parameter digit, the index in the string is the |
| * parameter to use. |
| */ |
| while (valid_parameters[parameter] != parameter_char && |
| valid_parameters[parameter] != '\0') |
| ++parameter; |
| |
| /* If the parameter digit is out of range it will just get printed. */ |
| if (parameter < PNG_WARNING_PARAMETER_COUNT) |
| { |
| /* Append this parameter */ |
| png_const_charp parm = p[parameter]; |
| png_const_charp pend = p[parameter] + (sizeof p[parameter]); |
| |
| /* No need to copy the trailing '\0' here, but there is no guarantee |
| * that parm[] has been initialized, so there is no guarantee of a |
| * trailing '\0': |
| */ |
| while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend) |
| msg[i++] = *parm++; |
| |
| /* Consume the parameter digit too: */ |
| ++message; |
| continue; |
| } |
| |
| /* else not a parameter and there is a character after the @ sign; just |
| * copy that. This is known not to be '\0' because of the test above. |
| */ |
| } |
| |
| /* At this point *message can't be '\0', even in the bad parameter case |
| * above where there is a lone '@' at the end of the message string. |
| */ |
| msg[i++] = *message++; |
| } |
| |
| /* i is always less than (sizeof msg), so: */ |
| msg[i] = '\0'; |
| |
| /* And this is the formatted message. It may be larger than |
| * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these |
| * are not (currently) formatted. |
| */ |
| png_warning(png_ptr, msg); |
| } |
| #endif /* WARNINGS */ |
| |
| #ifdef PNG_BENIGN_ERRORS_SUPPORTED |
| void PNGAPI |
| png_benign_error(png_const_structrp png_ptr, png_const_charp error_message) |
| { |
| if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) |
| { |
| # ifdef PNG_READ_SUPPORTED |
| if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && |
| png_ptr->chunk_name != 0) |
| png_chunk_warning(png_ptr, error_message); |
| else |
| # endif |
| png_warning(png_ptr, error_message); |
| } |
| |
| else |
| { |
| # ifdef PNG_READ_SUPPORTED |
| if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && |
| png_ptr->chunk_name != 0) |
| png_chunk_error(png_ptr, error_message); |
| else |
| # endif |
| png_error(png_ptr, error_message); |
| } |
| |
| # ifndef PNG_ERROR_TEXT_SUPPORTED |
| PNG_UNUSED(error_message) |
| # endif |
| } |
| |
| void /* PRIVATE */ |
| png_app_warning(png_const_structrp png_ptr, png_const_charp error_message) |
| { |
| if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0) |
| png_warning(png_ptr, error_message); |
| else |
| png_error(png_ptr, error_message); |
| |
| # ifndef PNG_ERROR_TEXT_SUPPORTED |
| PNG_UNUSED(error_message) |
| # endif |
| } |
| |
| void /* PRIVATE */ |
| png_app_error(png_const_structrp png_ptr, png_const_charp error_message) |
| { |
| if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0) |
| png_warning(png_ptr, error_message); |
| else |
| png_error(png_ptr, error_message); |
| |
| # ifndef PNG_ERROR_TEXT_SUPPORTED |
| PNG_UNUSED(error_message) |
| # endif |
| } |
| #endif /* BENIGN_ERRORS */ |
| |
| #define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */ |
| #if defined(PNG_WARNINGS_SUPPORTED) || \ |
| (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)) |
| /* These utilities are used internally to build an error message that relates |
| * to the current chunk. The chunk name comes from png_ptr->chunk_name, |
| * which is used to prefix the message. The message is limited in length |
| * to 63 bytes. The name characters are output as hex digits wrapped in [] |
| * if the character is invalid. |
| */ |
| #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) |
| static const char png_digit[16] = { |
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 'A', 'B', 'C', 'D', 'E', 'F' |
| }; |
| |
| static void /* PRIVATE */ |
| png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp |
| error_message) |
| { |
| png_uint_32 chunk_name = png_ptr->chunk_name; |
| int iout = 0, ishift = 24; |
| |
| while (ishift >= 0) |
| { |
| int c = (int)(chunk_name >> ishift) & 0xff; |
| |
| ishift -= 8; |
| if (isnonalpha(c) != 0) |
| { |
| buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; |
| buffer[iout++] = png_digit[(c & 0xf0) >> 4]; |
| buffer[iout++] = png_digit[c & 0x0f]; |
| buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET; |
| } |
| |
| else |
| { |
| buffer[iout++] = (char)c; |
| } |
| } |
| |
| if (error_message == NULL) |
| buffer[iout] = '\0'; |
| |
| else |
| { |
| int iin = 0; |
| |
| buffer[iout++] = ':'; |
| buffer[iout++] = ' '; |
| |
| while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0') |
| buffer[iout++] = error_message[iin++]; |
| |
| /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */ |
| buffer[iout] = '\0'; |
| } |
| } |
| #endif /* WARNINGS || ERROR_TEXT */ |
| |
| #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) |
| PNG_FUNCTION(void,PNGAPI |
| png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| PNG_NORETURN) |
| { |
| char msg[18+PNG_MAX_ERROR_TEXT]; |
| if (png_ptr == NULL) |
| png_error(png_ptr, error_message); |
| |
| else |
| { |
| png_format_buffer(png_ptr, msg, error_message); |
| png_error(png_ptr, msg); |
| } |
| } |
| #endif /* READ && ERROR_TEXT */ |
| |
| #ifdef PNG_WARNINGS_SUPPORTED |
| void PNGAPI |
| png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message) |
| { |
| char msg[18+PNG_MAX_ERROR_TEXT]; |
| if (png_ptr == NULL) |
| png_warning(png_ptr, warning_message); |
| |
| else |
| { |
| png_format_buffer(png_ptr, msg, warning_message); |
| png_warning(png_ptr, msg); |
| } |
| } |
| #endif /* WARNINGS */ |
| |
| #ifdef PNG_READ_SUPPORTED |
| #ifdef PNG_BENIGN_ERRORS_SUPPORTED |
| void PNGAPI |
| png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp |
| error_message) |
| { |
| if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) |
| png_chunk_warning(png_ptr, error_message); |
| |
| else |
| png_chunk_error(png_ptr, error_message); |
| |
| # ifndef PNG_ERROR_TEXT_SUPPORTED |
| PNG_UNUSED(error_message) |
| # endif |
| } |
| #endif |
| #endif /* READ */ |
| |
| void /* PRIVATE */ |
| png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error) |
| { |
| # ifndef PNG_WARNINGS_SUPPORTED |
| PNG_UNUSED(message) |
| # endif |
| |
| /* This is always supported, but for just read or just write it |
| * unconditionally does the right thing. |
| */ |
| # if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) |
| if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) |
| # endif |
| |
| # ifdef PNG_READ_SUPPORTED |
| { |
| if (error < PNG_CHUNK_ERROR) |
| png_chunk_warning(png_ptr, message); |
| |
| else |
| png_chunk_benign_error(png_ptr, message); |
| } |
| # endif |
| |
| # if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) |
| else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) |
| # endif |
| |
| # ifdef PNG_WRITE_SUPPORTED |
| { |
| if (error < PNG_CHUNK_WRITE_ERROR) |
| png_app_warning(png_ptr, message); |
| |
| else |
| png_app_error(png_ptr, message); |
| } |
| # endif |
| } |
| |
| #ifdef PNG_ERROR_TEXT_SUPPORTED |
| #ifdef PNG_FLOATING_POINT_SUPPORTED |
| PNG_FUNCTION(void, |
| png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN) |
| { |
| # define fixed_message "fixed point overflow in " |
| # define fixed_message_ln ((sizeof fixed_message)-1) |
| unsigned int iin; |
| char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT]; |
| memcpy(msg, fixed_message, fixed_message_ln); |
| iin = 0; |
| if (name != NULL) |
| while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0) |
| { |
| msg[fixed_message_ln + iin] = name[iin]; |
| ++iin; |
| } |
| msg[fixed_message_ln + iin] = 0; |
| png_error(png_ptr, msg); |
| } |
| #endif |
| #endif |
| |
| #ifdef PNG_SETJMP_SUPPORTED |
| /* This API only exists if ANSI-C style error handling is used, |
| * otherwise it is necessary for png_default_error to be overridden. |
| */ |
| jmp_buf* PNGAPI |
| png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn, |
| size_t jmp_buf_size) |
| { |
| /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value |
| * and it must not change after that. Libpng doesn't care how big the |
| * buffer is, just that it doesn't change. |
| * |
| * If the buffer size is no *larger* than the size of jmp_buf when libpng is |
| * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0 |
| * semantics that this call will not fail. If the size is larger, however, |
| * the buffer is allocated and this may fail, causing the function to return |
| * NULL. |
| */ |
| if (png_ptr == NULL) |
| return NULL; |
| |
| if (png_ptr->jmp_buf_ptr == NULL) |
| { |
| png_ptr->jmp_buf_size = 0; /* not allocated */ |
| |
| if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local)) |
| png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; |
| |
| else |
| { |
| png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *, |
| png_malloc_warn(png_ptr, jmp_buf_size)); |
| |
| if (png_ptr->jmp_buf_ptr == NULL) |
| return NULL; /* new NULL return on OOM */ |
| |
| png_ptr->jmp_buf_size = jmp_buf_size; |
| } |
| } |
| |
| else /* Already allocated: check the size */ |
| { |
| size_t size = png_ptr->jmp_buf_size; |
| |
| if (size == 0) |
| { |
| size = (sizeof png_ptr->jmp_buf_local); |
| if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local) |
| { |
| /* This is an internal error in libpng: somehow we have been left |
| * with a stack allocated jmp_buf when the application regained |
| * control. It's always possible to fix this up, but for the moment |
| * this is a png_error because that makes it easy to detect. |
| */ |
| png_error(png_ptr, "Libpng jmp_buf still allocated"); |
| /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */ |
| } |
| } |
| |
| if (size != jmp_buf_size) |
| { |
| png_warning(png_ptr, "Application jmp_buf size changed"); |
| return NULL; /* caller will probably crash: no choice here */ |
| } |
| } |
| |
| /* Finally fill in the function, now we have a satisfactory buffer. It is |
| * valid to change the function on every call. |
| */ |
| png_ptr->longjmp_fn = longjmp_fn; |
| return png_ptr->jmp_buf_ptr; |
| } |
| |
| void /* PRIVATE */ |
| png_free_jmpbuf(png_structrp png_ptr) |
| { |
| if (png_ptr != NULL) |
| { |
| jmp_buf *jb = png_ptr->jmp_buf_ptr; |
| |
| /* A size of 0 is used to indicate a local, stack, allocation of the |
| * pointer; used here and in png.c |
| */ |
| if (jb != NULL && png_ptr->jmp_buf_size > 0) |
| { |
| |
| /* This stuff is so that a failure to free the error control structure |
| * does not leave libpng in a state with no valid error handling: the |
| * free always succeeds, if there is an error it gets ignored. |
| */ |
| if (jb != &png_ptr->jmp_buf_local) |
| { |
| /* Make an internal, libpng, jmp_buf to return here */ |
| jmp_buf free_jmp_buf; |
| |
| if (!setjmp(free_jmp_buf)) |
| { |
| png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */ |
| png_ptr->jmp_buf_size = 0; /* stack allocation */ |
| png_ptr->longjmp_fn = longjmp; |
| png_free(png_ptr, jb); /* Return to setjmp on error */ |
| } |
| } |
| } |
| |
| /* *Always* cancel everything out: */ |
| png_ptr->jmp_buf_size = 0; |
| png_ptr->jmp_buf_ptr = NULL; |
| png_ptr->longjmp_fn = 0; |
| } |
| } |
| #endif |
| |
| /* This is the default error handling function. Note that replacements for |
| * this function MUST NOT RETURN, or the program will likely crash. This |
| * function is used by default, or if the program supplies NULL for the |
| * error function pointer in png_set_error_fn(). |
| */ |
| static PNG_FUNCTION(void /* PRIVATE */, |
| png_default_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| PNG_NORETURN) |
| { |
| #ifdef PNG_CONSOLE_IO_SUPPORTED |
| #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| /* Check on NULL only added in 1.5.4 */ |
| if (error_message != NULL && *error_message == PNG_LITERAL_SHARP) |
| { |
| /* Strip "#nnnn " from beginning of error message. */ |
| int offset; |
| char error_number[16]; |
| for (offset = 0; offset<15; offset++) |
| { |
| error_number[offset] = error_message[offset + 1]; |
| if (error_message[offset] == ' ') |
| break; |
| } |
| |
| if ((offset > 1) && (offset < 15)) |
| { |
| error_number[offset - 1] = '\0'; |
| fprintf(stderr, "libpng error no. %s: %s", |
| error_number, error_message + offset + 1); |
| fprintf(stderr, PNG_STRING_NEWLINE); |
| } |
| |
| else |
| { |
| fprintf(stderr, "libpng error: %s, offset=%d", |
| error_message, offset); |
| fprintf(stderr, PNG_STRING_NEWLINE); |
| } |
| } |
| else |
| #endif |
| { |
| fprintf(stderr, "libpng error: %s", error_message ? error_message : |
| "undefined"); |
| fprintf(stderr, PNG_STRING_NEWLINE); |
| } |
| #else |
| PNG_UNUSED(error_message) /* Make compiler happy */ |
| #endif |
| png_longjmp(png_ptr, 1); |
| } |
| |
| PNG_FUNCTION(void,PNGAPI |
| png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN) |
| { |
| #ifdef PNG_SETJMP_SUPPORTED |
| if (png_ptr != NULL && png_ptr->longjmp_fn != NULL && |
| png_ptr->jmp_buf_ptr != NULL) |
| png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val); |
| #else |
| PNG_UNUSED(png_ptr) |
| PNG_UNUSED(val) |
| #endif |
| |
| /* If control reaches this point, png_longjmp() must not return. The only |
| * choice is to terminate the whole process (or maybe the thread); to do |
| * this the ANSI-C abort() function is used unless a different method is |
| * implemented by overriding the default configuration setting for |
| * PNG_ABORT(). |
| */ |
| PNG_ABORT(); |
| } |
| |
| #ifdef PNG_WARNINGS_SUPPORTED |
| /* This function is called when there is a warning, but the library thinks |
| * it can continue anyway. Replacement functions don't have to do anything |
| * here if you don't want them to. In the default configuration, png_ptr is |
| * not used, but it is passed in case it may be useful. |
| */ |
| static void /* PRIVATE */ |
| png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message) |
| { |
| #ifdef PNG_CONSOLE_IO_SUPPORTED |
| # ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| if (*warning_message == PNG_LITERAL_SHARP) |
| { |
| int offset; |
| char warning_number[16]; |
| for (offset = 0; offset < 15; offset++) |
| { |
| warning_number[offset] = warning_message[offset + 1]; |
| if (warning_message[offset] == ' ') |
| break; |
| } |
| |
| if ((offset > 1) && (offset < 15)) |
| { |
| warning_number[offset + 1] = '\0'; |
| fprintf(stderr, "libpng warning no. %s: %s", |
| warning_number, warning_message + offset); |
| fprintf(stderr, PNG_STRING_NEWLINE); |
| } |
| |
| else |
| { |
| fprintf(stderr, "libpng warning: %s", |
| warning_message); |
| fprintf(stderr, PNG_STRING_NEWLINE); |
| } |
| } |
| else |
| # endif |
| |
| { |
| fprintf(stderr, "libpng warning: %s", warning_message); |
| fprintf(stderr, PNG_STRING_NEWLINE); |
| } |
| #else |
| PNG_UNUSED(warning_message) /* Make compiler happy */ |
| #endif |
| PNG_UNUSED(png_ptr) /* Make compiler happy */ |
| } |
| #endif /* WARNINGS */ |
| |
| /* This function is called when the application wants to use another method |
| * of handling errors and warnings. Note that the error function MUST NOT |
| * return to the calling routine or serious problems will occur. The return |
| * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1) |
| */ |
| void PNGAPI |
| png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr, |
| png_error_ptr error_fn, png_error_ptr warning_fn) |
| { |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->error_ptr = error_ptr; |
| png_ptr->error_fn = error_fn; |
| #ifdef PNG_WARNINGS_SUPPORTED |
| png_ptr->warning_fn = warning_fn; |
| #else |
| PNG_UNUSED(warning_fn) |
| #endif |
| } |
| |
| |
| /* This function returns a pointer to the error_ptr associated with the user |
| * functions. The application should free any memory associated with this |
| * pointer before png_write_destroy and png_read_destroy are called. |
| */ |
| png_voidp PNGAPI |
| png_get_error_ptr(png_const_structrp png_ptr) |
| { |
| if (png_ptr == NULL) |
| return NULL; |
| |
| return (png_voidp)png_ptr->error_ptr; |
| } |
| |
| |
| #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| void PNGAPI |
| png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode) |
| { |
| if (png_ptr != NULL) |
| { |
| png_ptr->flags &= |
| ((~(PNG_FLAG_STRIP_ERROR_NUMBERS | |
| PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); |
| } |
| } |
| #endif |
| |
| #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ |
| defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) |
| /* Currently the above both depend on SETJMP_SUPPORTED, however it would be |
| * possible to implement without setjmp support just so long as there is some |
| * way to handle the error return here: |
| */ |
| PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI |
| png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message), |
| PNG_NORETURN) |
| { |
| png_const_structrp png_ptr = png_nonconst_ptr; |
| png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); |
| |
| /* An error is always logged here, overwriting anything (typically a warning) |
| * that is already there: |
| */ |
| if (image != NULL) |
| { |
| png_safecat(image->message, (sizeof image->message), 0, error_message); |
| image->warning_or_error |= PNG_IMAGE_ERROR; |
| |
| /* Retrieve the jmp_buf from within the png_control, making this work for |
| * C++ compilation too is pretty tricky: C++ wants a pointer to the first |
| * element of a jmp_buf, but C doesn't tell us the type of that. |
| */ |
| if (image->opaque != NULL && image->opaque->error_buf != NULL) |
| longjmp(png_control_jmp_buf(image->opaque), 1); |
| |
| /* Missing longjmp buffer, the following is to help debugging: */ |
| { |
| size_t pos = png_safecat(image->message, (sizeof image->message), 0, |
| "bad longjmp: "); |
| png_safecat(image->message, (sizeof image->message), pos, |
| error_message); |
| } |
| } |
| |
| /* Here on an internal programming error. */ |
| abort(); |
| } |
| |
| #ifdef PNG_WARNINGS_SUPPORTED |
| void /* PRIVATE */ PNGCBAPI |
| png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message) |
| { |
| png_const_structrp png_ptr = png_nonconst_ptr; |
| png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); |
| |
| /* A warning is only logged if there is no prior warning or error. */ |
| if (image->warning_or_error == 0) |
| { |
| png_safecat(image->message, (sizeof image->message), 0, warning_message); |
| image->warning_or_error |= PNG_IMAGE_WARNING; |
| } |
| } |
| #endif |
| |
| int /* PRIVATE */ |
| png_safe_execute(png_imagep image, int (*function)(png_voidp), png_voidp arg) |
| { |
| png_voidp saved_error_buf = image->opaque->error_buf; |
| jmp_buf safe_jmpbuf; |
| int result; |
| |
| /* Safely execute function(arg), with png_error returning back here. */ |
| if (setjmp(safe_jmpbuf) == 0) |
| { |
| image->opaque->error_buf = safe_jmpbuf; |
| result = function(arg); |
| image->opaque->error_buf = saved_error_buf; |
| return result; |
| } |
| |
| /* On png_error, return via longjmp, pop the jmpbuf, and free the image. */ |
| image->opaque->error_buf = saved_error_buf; |
| png_image_free(image); |
| return 0; |
| } |
| #endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */ |
| #endif /* READ || WRITE */ |