scroggo | 3965825 | 2016-06-02 12:59:59 -0700 | [diff] [blame] | 1 | |
| 2 | /* pngerror.c - stub functions for i/o and memory allocation |
| 3 | * |
| 4 | * Last changed in libpng 1.6.15 [November 20, 2014] |
| 5 | * Copyright (c) 1998-2002,2004,2006-2014 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.) |
| 8 | * |
| 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 |
| 12 | * |
| 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 |
| 16 | * at each function. |
| 17 | */ |
| 18 | |
| 19 | #include "pngpriv.h" |
| 20 | |
| 21 | #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
| 22 | |
| 23 | static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr, |
| 24 | png_const_charp error_message)),PNG_NORETURN); |
| 25 | |
| 26 | #ifdef PNG_WARNINGS_SUPPORTED |
| 27 | static void /* PRIVATE */ |
| 28 | png_default_warning PNGARG((png_const_structrp png_ptr, |
| 29 | png_const_charp warning_message)); |
| 30 | #endif /* WARNINGS */ |
| 31 | |
| 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. |
| 36 | */ |
| 37 | #ifdef PNG_ERROR_TEXT_SUPPORTED |
| 38 | PNG_FUNCTION(void,PNGAPI |
| 39 | png_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| 40 | PNG_NORETURN) |
| 41 | { |
| 42 | #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| 43 | char msg[16]; |
| 44 | if (png_ptr != NULL) |
| 45 | { |
| 46 | if ((png_ptr->flags & |
| 47 | (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0 |
| 48 | { |
| 49 | if (*error_message == PNG_LITERAL_SHARP) |
| 50 | { |
| 51 | /* Strip "#nnnn " from beginning of error message. */ |
| 52 | int offset; |
| 53 | for (offset = 1; offset<15; offset++) |
| 54 | if (error_message[offset] == ' ') |
| 55 | break; |
| 56 | |
| 57 | if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) |
| 58 | { |
| 59 | int i; |
| 60 | for (i = 0; i < offset - 1; i++) |
| 61 | msg[i] = error_message[i + 1]; |
| 62 | msg[i - 1] = '\0'; |
| 63 | error_message = msg; |
| 64 | } |
| 65 | |
| 66 | else |
| 67 | error_message += offset; |
| 68 | } |
| 69 | |
| 70 | else |
| 71 | { |
| 72 | if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) |
| 73 | { |
| 74 | msg[0] = '0'; |
| 75 | msg[1] = '\0'; |
| 76 | error_message = msg; |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | } |
| 81 | #endif |
| 82 | if (png_ptr != NULL && png_ptr->error_fn != NULL) |
| 83 | (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), |
| 84 | error_message); |
| 85 | |
| 86 | /* If the custom handler doesn't exist, or if it returns, |
| 87 | use the default handler, which will not return. */ |
| 88 | png_default_error(png_ptr, error_message); |
| 89 | } |
| 90 | #else |
| 91 | PNG_FUNCTION(void,PNGAPI |
| 92 | png_err,(png_const_structrp png_ptr),PNG_NORETURN) |
| 93 | { |
| 94 | /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed |
| 95 | * erroneously as '\0', instead of the empty string "". This was |
| 96 | * apparently an error, introduced in libpng-1.2.20, and png_default_error |
| 97 | * will crash in this case. |
| 98 | */ |
| 99 | if (png_ptr != NULL && png_ptr->error_fn != NULL) |
| 100 | (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), ""); |
| 101 | |
| 102 | /* If the custom handler doesn't exist, or if it returns, |
| 103 | use the default handler, which will not return. */ |
| 104 | png_default_error(png_ptr, ""); |
| 105 | } |
| 106 | #endif /* ERROR_TEXT */ |
| 107 | |
| 108 | /* Utility to safely appends strings to a buffer. This never errors out so |
| 109 | * error checking is not required in the caller. |
| 110 | */ |
| 111 | size_t |
| 112 | png_safecat(png_charp buffer, size_t bufsize, size_t pos, |
| 113 | png_const_charp string) |
| 114 | { |
| 115 | if (buffer != NULL && pos < bufsize) |
| 116 | { |
| 117 | if (string != NULL) |
| 118 | while (*string != '\0' && pos < bufsize-1) |
| 119 | buffer[pos++] = *string++; |
| 120 | |
| 121 | buffer[pos] = '\0'; |
| 122 | } |
| 123 | |
| 124 | return pos; |
| 125 | } |
| 126 | |
| 127 | #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) |
| 128 | /* Utility to dump an unsigned value into a buffer, given a start pointer and |
| 129 | * and end pointer (which should point just *beyond* the end of the buffer!) |
| 130 | * Returns the pointer to the start of the formatted string. |
| 131 | */ |
| 132 | png_charp |
| 133 | png_format_number(png_const_charp start, png_charp end, int format, |
| 134 | png_alloc_size_t number) |
| 135 | { |
| 136 | int count = 0; /* number of digits output */ |
| 137 | int mincount = 1; /* minimum number required */ |
| 138 | int output = 0; /* digit output (for the fixed point format) */ |
| 139 | |
| 140 | *--end = '\0'; |
| 141 | |
| 142 | /* This is written so that the loop always runs at least once, even with |
| 143 | * number zero. |
| 144 | */ |
| 145 | while (end > start && (number != 0 || count < mincount)) |
| 146 | { |
| 147 | |
| 148 | static const char digits[] = "0123456789ABCDEF"; |
| 149 | |
| 150 | switch (format) |
| 151 | { |
| 152 | case PNG_NUMBER_FORMAT_fixed: |
| 153 | /* Needs five digits (the fraction) */ |
| 154 | mincount = 5; |
| 155 | if (output != 0 || number % 10 != 0) |
| 156 | { |
| 157 | *--end = digits[number % 10]; |
| 158 | output = 1; |
| 159 | } |
| 160 | number /= 10; |
| 161 | break; |
| 162 | |
| 163 | case PNG_NUMBER_FORMAT_02u: |
| 164 | /* Expects at least 2 digits. */ |
| 165 | mincount = 2; |
| 166 | /* FALL THROUGH */ |
| 167 | |
| 168 | case PNG_NUMBER_FORMAT_u: |
| 169 | *--end = digits[number % 10]; |
| 170 | number /= 10; |
| 171 | break; |
| 172 | |
| 173 | case PNG_NUMBER_FORMAT_02x: |
| 174 | /* This format expects at least two digits */ |
| 175 | mincount = 2; |
| 176 | /* FALL THROUGH */ |
| 177 | |
| 178 | case PNG_NUMBER_FORMAT_x: |
| 179 | *--end = digits[number & 0xf]; |
| 180 | number >>= 4; |
| 181 | break; |
| 182 | |
| 183 | default: /* an error */ |
| 184 | number = 0; |
| 185 | break; |
| 186 | } |
| 187 | |
| 188 | /* Keep track of the number of digits added */ |
| 189 | ++count; |
| 190 | |
| 191 | /* Float a fixed number here: */ |
| 192 | if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start)) |
| 193 | { |
| 194 | /* End of the fraction, but maybe nothing was output? In that case |
| 195 | * drop the decimal point. If the number is a true zero handle that |
| 196 | * here. |
| 197 | */ |
| 198 | if (output != 0) |
| 199 | *--end = '.'; |
| 200 | else if (number == 0) /* and !output */ |
| 201 | *--end = '0'; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | return end; |
| 206 | } |
| 207 | #endif |
| 208 | |
| 209 | #ifdef PNG_WARNINGS_SUPPORTED |
| 210 | /* This function is called whenever there is a non-fatal error. This function |
| 211 | * should not be changed. If there is a need to handle warnings differently, |
| 212 | * you should supply a replacement warning function and use |
| 213 | * png_set_error_fn() to replace the warning function at run-time. |
| 214 | */ |
| 215 | void PNGAPI |
| 216 | png_warning(png_const_structrp png_ptr, png_const_charp warning_message) |
| 217 | { |
| 218 | int offset = 0; |
| 219 | if (png_ptr != NULL) |
| 220 | { |
| 221 | #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| 222 | if ((png_ptr->flags & |
| 223 | (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) |
| 224 | #endif |
| 225 | { |
| 226 | if (*warning_message == PNG_LITERAL_SHARP) |
| 227 | { |
| 228 | for (offset = 1; offset < 15; offset++) |
| 229 | if (warning_message[offset] == ' ') |
| 230 | break; |
| 231 | } |
| 232 | } |
| 233 | } |
| 234 | if (png_ptr != NULL && png_ptr->warning_fn != NULL) |
| 235 | (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr), |
| 236 | warning_message + offset); |
| 237 | else |
| 238 | png_default_warning(png_ptr, warning_message + offset); |
| 239 | } |
| 240 | |
| 241 | /* These functions support 'formatted' warning messages with up to |
| 242 | * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter |
| 243 | * is introduced by @<number>, where 'number' starts at 1. This follows the |
| 244 | * standard established by X/Open for internationalizable error messages. |
| 245 | */ |
| 246 | void |
| 247 | png_warning_parameter(png_warning_parameters p, int number, |
| 248 | png_const_charp string) |
| 249 | { |
| 250 | if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT) |
| 251 | (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string); |
| 252 | } |
| 253 | |
| 254 | void |
| 255 | png_warning_parameter_unsigned(png_warning_parameters p, int number, int format, |
| 256 | png_alloc_size_t value) |
| 257 | { |
| 258 | char buffer[PNG_NUMBER_BUFFER_SIZE]; |
| 259 | png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value)); |
| 260 | } |
| 261 | |
| 262 | void |
| 263 | png_warning_parameter_signed(png_warning_parameters p, int number, int format, |
| 264 | png_int_32 value) |
| 265 | { |
| 266 | png_alloc_size_t u; |
| 267 | png_charp str; |
| 268 | char buffer[PNG_NUMBER_BUFFER_SIZE]; |
| 269 | |
| 270 | /* Avoid overflow by doing the negate in a png_alloc_size_t: */ |
| 271 | u = (png_alloc_size_t)value; |
| 272 | if (value < 0) |
| 273 | u = ~u + 1; |
| 274 | |
| 275 | str = PNG_FORMAT_NUMBER(buffer, format, u); |
| 276 | |
| 277 | if (value < 0 && str > buffer) |
| 278 | *--str = '-'; |
| 279 | |
| 280 | png_warning_parameter(p, number, str); |
| 281 | } |
| 282 | |
| 283 | void |
| 284 | png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p, |
| 285 | png_const_charp message) |
| 286 | { |
| 287 | /* The internal buffer is just 192 bytes - enough for all our messages, |
| 288 | * overflow doesn't happen because this code checks! If someone figures |
| 289 | * out how to send us a message longer than 192 bytes, all that will |
| 290 | * happen is that the message will be truncated appropriately. |
| 291 | */ |
| 292 | size_t i = 0; /* Index in the msg[] buffer: */ |
| 293 | char msg[192]; |
| 294 | |
| 295 | /* Each iteration through the following loop writes at most one character |
| 296 | * to msg[i++] then returns here to validate that there is still space for |
| 297 | * the trailing '\0'. It may (in the case of a parameter) read more than |
| 298 | * one character from message[]; it must check for '\0' and continue to the |
| 299 | * test if it finds the end of string. |
| 300 | */ |
| 301 | while (i<(sizeof msg)-1 && *message != '\0') |
| 302 | { |
| 303 | /* '@' at end of string is now just printed (previously it was skipped); |
| 304 | * it is an error in the calling code to terminate the string with @. |
| 305 | */ |
| 306 | if (p != NULL && *message == '@' && message[1] != '\0') |
| 307 | { |
| 308 | int parameter_char = *++message; /* Consume the '@' */ |
| 309 | static const char valid_parameters[] = "123456789"; |
| 310 | int parameter = 0; |
| 311 | |
| 312 | /* Search for the parameter digit, the index in the string is the |
| 313 | * parameter to use. |
| 314 | */ |
| 315 | while (valid_parameters[parameter] != parameter_char && |
| 316 | valid_parameters[parameter] != '\0') |
| 317 | ++parameter; |
| 318 | |
| 319 | /* If the parameter digit is out of range it will just get printed. */ |
| 320 | if (parameter < PNG_WARNING_PARAMETER_COUNT) |
| 321 | { |
| 322 | /* Append this parameter */ |
| 323 | png_const_charp parm = p[parameter]; |
| 324 | png_const_charp pend = p[parameter] + (sizeof p[parameter]); |
| 325 | |
| 326 | /* No need to copy the trailing '\0' here, but there is no guarantee |
| 327 | * that parm[] has been initialized, so there is no guarantee of a |
| 328 | * trailing '\0': |
| 329 | */ |
| 330 | while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend) |
| 331 | msg[i++] = *parm++; |
| 332 | |
| 333 | /* Consume the parameter digit too: */ |
| 334 | ++message; |
| 335 | continue; |
| 336 | } |
| 337 | |
| 338 | /* else not a parameter and there is a character after the @ sign; just |
| 339 | * copy that. This is known not to be '\0' because of the test above. |
| 340 | */ |
| 341 | } |
| 342 | |
| 343 | /* At this point *message can't be '\0', even in the bad parameter case |
| 344 | * above where there is a lone '@' at the end of the message string. |
| 345 | */ |
| 346 | msg[i++] = *message++; |
| 347 | } |
| 348 | |
| 349 | /* i is always less than (sizeof msg), so: */ |
| 350 | msg[i] = '\0'; |
| 351 | |
| 352 | /* And this is the formatted message. It may be larger than |
| 353 | * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these |
| 354 | * are not (currently) formatted. |
| 355 | */ |
| 356 | png_warning(png_ptr, msg); |
| 357 | } |
| 358 | #endif /* WARNINGS */ |
| 359 | |
| 360 | #ifdef PNG_BENIGN_ERRORS_SUPPORTED |
| 361 | void PNGAPI |
| 362 | png_benign_error(png_const_structrp png_ptr, png_const_charp error_message) |
| 363 | { |
| 364 | if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) |
| 365 | { |
| 366 | # ifdef PNG_READ_SUPPORTED |
| 367 | if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && |
| 368 | png_ptr->chunk_name != 0) |
| 369 | png_chunk_warning(png_ptr, error_message); |
| 370 | else |
| 371 | # endif |
| 372 | png_warning(png_ptr, error_message); |
| 373 | } |
| 374 | |
| 375 | else |
| 376 | { |
| 377 | # ifdef PNG_READ_SUPPORTED |
| 378 | if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && |
| 379 | png_ptr->chunk_name != 0) |
| 380 | png_chunk_error(png_ptr, error_message); |
| 381 | else |
| 382 | # endif |
| 383 | png_error(png_ptr, error_message); |
| 384 | } |
| 385 | |
| 386 | # ifndef PNG_ERROR_TEXT_SUPPORTED |
| 387 | PNG_UNUSED(error_message) |
| 388 | # endif |
| 389 | } |
| 390 | |
| 391 | void /* PRIVATE */ |
| 392 | png_app_warning(png_const_structrp png_ptr, png_const_charp error_message) |
| 393 | { |
| 394 | if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0) |
| 395 | png_warning(png_ptr, error_message); |
| 396 | else |
| 397 | png_error(png_ptr, error_message); |
| 398 | |
| 399 | # ifndef PNG_ERROR_TEXT_SUPPORTED |
| 400 | PNG_UNUSED(error_message) |
| 401 | # endif |
| 402 | } |
| 403 | |
| 404 | void /* PRIVATE */ |
| 405 | png_app_error(png_const_structrp png_ptr, png_const_charp error_message) |
| 406 | { |
| 407 | if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0) |
| 408 | png_warning(png_ptr, error_message); |
| 409 | else |
| 410 | png_error(png_ptr, error_message); |
| 411 | |
| 412 | # ifndef PNG_ERROR_TEXT_SUPPORTED |
| 413 | PNG_UNUSED(error_message) |
| 414 | # endif |
| 415 | } |
| 416 | #endif /* BENIGN_ERRORS */ |
| 417 | |
| 418 | #define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */ |
| 419 | #if defined(PNG_WARNINGS_SUPPORTED) || \ |
| 420 | (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)) |
| 421 | /* These utilities are used internally to build an error message that relates |
| 422 | * to the current chunk. The chunk name comes from png_ptr->chunk_name, |
| 423 | * which is used to prefix the message. The message is limited in length |
| 424 | * to 63 bytes. The name characters are output as hex digits wrapped in [] |
| 425 | * if the character is invalid. |
| 426 | */ |
| 427 | #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) |
| 428 | static PNG_CONST char png_digit[16] = { |
| 429 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 430 | 'A', 'B', 'C', 'D', 'E', 'F' |
| 431 | }; |
| 432 | |
| 433 | static void /* PRIVATE */ |
| 434 | png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp |
| 435 | error_message) |
| 436 | { |
| 437 | png_uint_32 chunk_name = png_ptr->chunk_name; |
| 438 | int iout = 0, ishift = 24; |
| 439 | |
| 440 | while (ishift >= 0) |
| 441 | { |
| 442 | int c = (int)(chunk_name >> ishift) & 0xff; |
| 443 | |
| 444 | ishift -= 8; |
| 445 | if (isnonalpha(c) != 0) |
| 446 | { |
| 447 | buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; |
| 448 | buffer[iout++] = png_digit[(c & 0xf0) >> 4]; |
| 449 | buffer[iout++] = png_digit[c & 0x0f]; |
| 450 | buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET; |
| 451 | } |
| 452 | |
| 453 | else |
| 454 | { |
| 455 | buffer[iout++] = (char)c; |
| 456 | } |
| 457 | } |
| 458 | |
| 459 | if (error_message == NULL) |
| 460 | buffer[iout] = '\0'; |
| 461 | |
| 462 | else |
| 463 | { |
| 464 | int iin = 0; |
| 465 | |
| 466 | buffer[iout++] = ':'; |
| 467 | buffer[iout++] = ' '; |
| 468 | |
| 469 | while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0') |
| 470 | buffer[iout++] = error_message[iin++]; |
| 471 | |
| 472 | /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */ |
| 473 | buffer[iout] = '\0'; |
| 474 | } |
| 475 | } |
| 476 | #endif /* WARNINGS || ERROR_TEXT */ |
| 477 | |
| 478 | #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) |
| 479 | PNG_FUNCTION(void,PNGAPI |
| 480 | png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| 481 | PNG_NORETURN) |
| 482 | { |
| 483 | char msg[18+PNG_MAX_ERROR_TEXT]; |
| 484 | if (png_ptr == NULL) |
| 485 | png_error(png_ptr, error_message); |
| 486 | |
| 487 | else |
| 488 | { |
| 489 | png_format_buffer(png_ptr, msg, error_message); |
| 490 | png_error(png_ptr, msg); |
| 491 | } |
| 492 | } |
| 493 | #endif /* READ && ERROR_TEXT */ |
| 494 | |
| 495 | #ifdef PNG_WARNINGS_SUPPORTED |
| 496 | void PNGAPI |
| 497 | png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message) |
| 498 | { |
| 499 | char msg[18+PNG_MAX_ERROR_TEXT]; |
| 500 | if (png_ptr == NULL) |
| 501 | png_warning(png_ptr, warning_message); |
| 502 | |
| 503 | else |
| 504 | { |
| 505 | png_format_buffer(png_ptr, msg, warning_message); |
| 506 | png_warning(png_ptr, msg); |
| 507 | } |
| 508 | } |
| 509 | #endif /* WARNINGS */ |
| 510 | |
| 511 | #ifdef PNG_READ_SUPPORTED |
| 512 | #ifdef PNG_BENIGN_ERRORS_SUPPORTED |
| 513 | void PNGAPI |
| 514 | png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp |
| 515 | error_message) |
| 516 | { |
| 517 | if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) |
| 518 | png_chunk_warning(png_ptr, error_message); |
| 519 | |
| 520 | else |
| 521 | png_chunk_error(png_ptr, error_message); |
| 522 | |
| 523 | # ifndef PNG_ERROR_TEXT_SUPPORTED |
| 524 | PNG_UNUSED(error_message) |
| 525 | # endif |
| 526 | } |
| 527 | #endif |
| 528 | #endif /* READ */ |
| 529 | |
| 530 | void /* PRIVATE */ |
| 531 | png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error) |
| 532 | { |
| 533 | # ifndef PNG_WARNINGS_SUPPORTED |
| 534 | PNG_UNUSED(message) |
| 535 | # endif |
| 536 | |
| 537 | /* This is always supported, but for just read or just write it |
| 538 | * unconditionally does the right thing. |
| 539 | */ |
| 540 | # if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) |
| 541 | if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) |
| 542 | # endif |
| 543 | |
| 544 | # ifdef PNG_READ_SUPPORTED |
| 545 | { |
| 546 | if (error < PNG_CHUNK_ERROR) |
| 547 | png_chunk_warning(png_ptr, message); |
| 548 | |
| 549 | else |
| 550 | png_chunk_benign_error(png_ptr, message); |
| 551 | } |
| 552 | # endif |
| 553 | |
| 554 | # if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) |
| 555 | else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) |
| 556 | # endif |
| 557 | |
| 558 | # ifdef PNG_WRITE_SUPPORTED |
| 559 | { |
| 560 | if (error < PNG_CHUNK_WRITE_ERROR) |
| 561 | png_app_warning(png_ptr, message); |
| 562 | |
| 563 | else |
| 564 | png_app_error(png_ptr, message); |
| 565 | } |
| 566 | # endif |
| 567 | } |
| 568 | |
| 569 | #ifdef PNG_ERROR_TEXT_SUPPORTED |
| 570 | #ifdef PNG_FLOATING_POINT_SUPPORTED |
| 571 | PNG_FUNCTION(void, |
| 572 | png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN) |
| 573 | { |
| 574 | # define fixed_message "fixed point overflow in " |
| 575 | # define fixed_message_ln ((sizeof fixed_message)-1) |
| 576 | int iin; |
| 577 | char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT]; |
| 578 | memcpy(msg, fixed_message, fixed_message_ln); |
| 579 | iin = 0; |
| 580 | if (name != NULL) |
| 581 | while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0) |
| 582 | { |
| 583 | msg[fixed_message_ln + iin] = name[iin]; |
| 584 | ++iin; |
| 585 | } |
| 586 | msg[fixed_message_ln + iin] = 0; |
| 587 | png_error(png_ptr, msg); |
| 588 | } |
| 589 | #endif |
| 590 | #endif |
| 591 | |
| 592 | #ifdef PNG_SETJMP_SUPPORTED |
| 593 | /* This API only exists if ANSI-C style error handling is used, |
| 594 | * otherwise it is necessary for png_default_error to be overridden. |
| 595 | */ |
| 596 | jmp_buf* PNGAPI |
| 597 | png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn, |
| 598 | size_t jmp_buf_size) |
| 599 | { |
| 600 | /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value |
| 601 | * and it must not change after that. Libpng doesn't care how big the |
| 602 | * buffer is, just that it doesn't change. |
| 603 | * |
| 604 | * If the buffer size is no *larger* than the size of jmp_buf when libpng is |
| 605 | * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0 |
| 606 | * semantics that this call will not fail. If the size is larger, however, |
| 607 | * the buffer is allocated and this may fail, causing the function to return |
| 608 | * NULL. |
| 609 | */ |
| 610 | if (png_ptr == NULL) |
| 611 | return NULL; |
| 612 | |
| 613 | if (png_ptr->jmp_buf_ptr == NULL) |
| 614 | { |
| 615 | png_ptr->jmp_buf_size = 0; /* not allocated */ |
| 616 | |
| 617 | if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local)) |
| 618 | png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; |
| 619 | |
| 620 | else |
| 621 | { |
| 622 | png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *, |
| 623 | png_malloc_warn(png_ptr, jmp_buf_size)); |
| 624 | |
| 625 | if (png_ptr->jmp_buf_ptr == NULL) |
| 626 | return NULL; /* new NULL return on OOM */ |
| 627 | |
| 628 | png_ptr->jmp_buf_size = jmp_buf_size; |
| 629 | } |
| 630 | } |
| 631 | |
| 632 | else /* Already allocated: check the size */ |
| 633 | { |
| 634 | size_t size = png_ptr->jmp_buf_size; |
| 635 | |
| 636 | if (size == 0) |
| 637 | { |
| 638 | size = (sizeof png_ptr->jmp_buf_local); |
| 639 | if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local) |
| 640 | { |
| 641 | /* This is an internal error in libpng: somehow we have been left |
| 642 | * with a stack allocated jmp_buf when the application regained |
| 643 | * control. It's always possible to fix this up, but for the moment |
| 644 | * this is a png_error because that makes it easy to detect. |
| 645 | */ |
| 646 | png_error(png_ptr, "Libpng jmp_buf still allocated"); |
| 647 | /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */ |
| 648 | } |
| 649 | } |
| 650 | |
| 651 | if (size != jmp_buf_size) |
| 652 | { |
| 653 | png_warning(png_ptr, "Application jmp_buf size changed"); |
| 654 | return NULL; /* caller will probably crash: no choice here */ |
| 655 | } |
| 656 | } |
| 657 | |
| 658 | /* Finally fill in the function, now we have a satisfactory buffer. It is |
| 659 | * valid to change the function on every call. |
| 660 | */ |
| 661 | png_ptr->longjmp_fn = longjmp_fn; |
| 662 | return png_ptr->jmp_buf_ptr; |
| 663 | } |
| 664 | |
| 665 | void /* PRIVATE */ |
| 666 | png_free_jmpbuf(png_structrp png_ptr) |
| 667 | { |
| 668 | if (png_ptr != NULL) |
| 669 | { |
| 670 | jmp_buf *jb = png_ptr->jmp_buf_ptr; |
| 671 | |
| 672 | /* A size of 0 is used to indicate a local, stack, allocation of the |
| 673 | * pointer; used here and in png.c |
| 674 | */ |
| 675 | if (jb != NULL && png_ptr->jmp_buf_size > 0) |
| 676 | { |
| 677 | |
| 678 | /* This stuff is so that a failure to free the error control structure |
| 679 | * does not leave libpng in a state with no valid error handling: the |
| 680 | * free always succeeds, if there is an error it gets ignored. |
| 681 | */ |
| 682 | if (jb != &png_ptr->jmp_buf_local) |
| 683 | { |
| 684 | /* Make an internal, libpng, jmp_buf to return here */ |
| 685 | jmp_buf free_jmp_buf; |
| 686 | |
| 687 | if (!setjmp(free_jmp_buf)) |
| 688 | { |
| 689 | png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */ |
| 690 | png_ptr->jmp_buf_size = 0; /* stack allocation */ |
| 691 | png_ptr->longjmp_fn = longjmp; |
| 692 | png_free(png_ptr, jb); /* Return to setjmp on error */ |
| 693 | } |
| 694 | } |
| 695 | } |
| 696 | |
| 697 | /* *Always* cancel everything out: */ |
| 698 | png_ptr->jmp_buf_size = 0; |
| 699 | png_ptr->jmp_buf_ptr = NULL; |
| 700 | png_ptr->longjmp_fn = 0; |
| 701 | } |
| 702 | } |
| 703 | #endif |
| 704 | |
| 705 | /* This is the default error handling function. Note that replacements for |
| 706 | * this function MUST NOT RETURN, or the program will likely crash. This |
| 707 | * function is used by default, or if the program supplies NULL for the |
| 708 | * error function pointer in png_set_error_fn(). |
| 709 | */ |
| 710 | static PNG_FUNCTION(void /* PRIVATE */, |
| 711 | png_default_error,(png_const_structrp png_ptr, png_const_charp error_message), |
| 712 | PNG_NORETURN) |
| 713 | { |
| 714 | #ifdef PNG_CONSOLE_IO_SUPPORTED |
| 715 | #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| 716 | /* Check on NULL only added in 1.5.4 */ |
| 717 | if (error_message != NULL && *error_message == PNG_LITERAL_SHARP) |
| 718 | { |
| 719 | /* Strip "#nnnn " from beginning of error message. */ |
| 720 | int offset; |
| 721 | char error_number[16]; |
| 722 | for (offset = 0; offset<15; offset++) |
| 723 | { |
| 724 | error_number[offset] = error_message[offset + 1]; |
| 725 | if (error_message[offset] == ' ') |
| 726 | break; |
| 727 | } |
| 728 | |
| 729 | if ((offset > 1) && (offset < 15)) |
| 730 | { |
| 731 | error_number[offset - 1] = '\0'; |
| 732 | fprintf(stderr, "libpng error no. %s: %s", |
| 733 | error_number, error_message + offset + 1); |
| 734 | fprintf(stderr, PNG_STRING_NEWLINE); |
| 735 | } |
| 736 | |
| 737 | else |
| 738 | { |
| 739 | fprintf(stderr, "libpng error: %s, offset=%d", |
| 740 | error_message, offset); |
| 741 | fprintf(stderr, PNG_STRING_NEWLINE); |
| 742 | } |
| 743 | } |
| 744 | else |
| 745 | #endif |
| 746 | { |
| 747 | fprintf(stderr, "libpng error: %s", error_message ? error_message : |
| 748 | "undefined"); |
| 749 | fprintf(stderr, PNG_STRING_NEWLINE); |
| 750 | } |
| 751 | #else |
| 752 | PNG_UNUSED(error_message) /* Make compiler happy */ |
| 753 | #endif |
| 754 | png_longjmp(png_ptr, 1); |
| 755 | } |
| 756 | |
| 757 | PNG_FUNCTION(void,PNGAPI |
| 758 | png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN) |
| 759 | { |
| 760 | #ifdef PNG_SETJMP_SUPPORTED |
| 761 | if (png_ptr != NULL && png_ptr->longjmp_fn != NULL && |
| 762 | png_ptr->jmp_buf_ptr != NULL) |
| 763 | png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val); |
| 764 | #else |
| 765 | PNG_UNUSED(png_ptr) |
| 766 | PNG_UNUSED(val) |
| 767 | #endif |
| 768 | |
| 769 | /* If control reaches this point, png_longjmp() must not return. The only |
| 770 | * choice is to terminate the whole process (or maybe the thread); to do |
| 771 | * this the ANSI-C abort() function is used unless a different method is |
| 772 | * implemented by overriding the default configuration setting for |
| 773 | * PNG_ABORT(). |
| 774 | */ |
| 775 | PNG_ABORT(); |
| 776 | } |
| 777 | |
| 778 | #ifdef PNG_WARNINGS_SUPPORTED |
| 779 | /* This function is called when there is a warning, but the library thinks |
| 780 | * it can continue anyway. Replacement functions don't have to do anything |
| 781 | * here if you don't want them to. In the default configuration, png_ptr is |
| 782 | * not used, but it is passed in case it may be useful. |
| 783 | */ |
| 784 | static void /* PRIVATE */ |
| 785 | png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message) |
| 786 | { |
| 787 | #ifdef PNG_CONSOLE_IO_SUPPORTED |
| 788 | # ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| 789 | if (*warning_message == PNG_LITERAL_SHARP) |
| 790 | { |
| 791 | int offset; |
| 792 | char warning_number[16]; |
| 793 | for (offset = 0; offset < 15; offset++) |
| 794 | { |
| 795 | warning_number[offset] = warning_message[offset + 1]; |
| 796 | if (warning_message[offset] == ' ') |
| 797 | break; |
| 798 | } |
| 799 | |
| 800 | if ((offset > 1) && (offset < 15)) |
| 801 | { |
| 802 | warning_number[offset + 1] = '\0'; |
| 803 | fprintf(stderr, "libpng warning no. %s: %s", |
| 804 | warning_number, warning_message + offset); |
| 805 | fprintf(stderr, PNG_STRING_NEWLINE); |
| 806 | } |
| 807 | |
| 808 | else |
| 809 | { |
| 810 | fprintf(stderr, "libpng warning: %s", |
| 811 | warning_message); |
| 812 | fprintf(stderr, PNG_STRING_NEWLINE); |
| 813 | } |
| 814 | } |
| 815 | else |
| 816 | # endif |
| 817 | |
| 818 | { |
| 819 | fprintf(stderr, "libpng warning: %s", warning_message); |
| 820 | fprintf(stderr, PNG_STRING_NEWLINE); |
| 821 | } |
| 822 | #else |
| 823 | PNG_UNUSED(warning_message) /* Make compiler happy */ |
| 824 | #endif |
| 825 | PNG_UNUSED(png_ptr) /* Make compiler happy */ |
| 826 | } |
| 827 | #endif /* WARNINGS */ |
| 828 | |
| 829 | /* This function is called when the application wants to use another method |
| 830 | * of handling errors and warnings. Note that the error function MUST NOT |
| 831 | * return to the calling routine or serious problems will occur. The return |
| 832 | * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1) |
| 833 | */ |
| 834 | void PNGAPI |
| 835 | png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr, |
| 836 | png_error_ptr error_fn, png_error_ptr warning_fn) |
| 837 | { |
| 838 | if (png_ptr == NULL) |
| 839 | return; |
| 840 | |
| 841 | png_ptr->error_ptr = error_ptr; |
| 842 | png_ptr->error_fn = error_fn; |
| 843 | #ifdef PNG_WARNINGS_SUPPORTED |
| 844 | png_ptr->warning_fn = warning_fn; |
| 845 | #else |
| 846 | PNG_UNUSED(warning_fn) |
| 847 | #endif |
| 848 | } |
| 849 | |
| 850 | |
| 851 | /* This function returns a pointer to the error_ptr associated with the user |
| 852 | * functions. The application should free any memory associated with this |
| 853 | * pointer before png_write_destroy and png_read_destroy are called. |
| 854 | */ |
| 855 | png_voidp PNGAPI |
| 856 | png_get_error_ptr(png_const_structrp png_ptr) |
| 857 | { |
| 858 | if (png_ptr == NULL) |
| 859 | return NULL; |
| 860 | |
| 861 | return ((png_voidp)png_ptr->error_ptr); |
| 862 | } |
| 863 | |
| 864 | |
| 865 | #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| 866 | void PNGAPI |
| 867 | png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode) |
| 868 | { |
| 869 | if (png_ptr != NULL) |
| 870 | { |
| 871 | png_ptr->flags &= |
| 872 | ((~(PNG_FLAG_STRIP_ERROR_NUMBERS | |
| 873 | PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); |
| 874 | } |
| 875 | } |
| 876 | #endif |
| 877 | |
| 878 | #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ |
| 879 | defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) |
| 880 | /* Currently the above both depend on SETJMP_SUPPORTED, however it would be |
| 881 | * possible to implement without setjmp support just so long as there is some |
| 882 | * way to handle the error return here: |
| 883 | */ |
| 884 | PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI |
| 885 | png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message), |
| 886 | PNG_NORETURN) |
| 887 | { |
| 888 | const png_const_structrp png_ptr = png_nonconst_ptr; |
| 889 | png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); |
| 890 | |
| 891 | /* An error is always logged here, overwriting anything (typically a warning) |
| 892 | * that is already there: |
| 893 | */ |
| 894 | if (image != NULL) |
| 895 | { |
| 896 | png_safecat(image->message, (sizeof image->message), 0, error_message); |
| 897 | image->warning_or_error |= PNG_IMAGE_ERROR; |
| 898 | |
| 899 | /* Retrieve the jmp_buf from within the png_control, making this work for |
| 900 | * C++ compilation too is pretty tricky: C++ wants a pointer to the first |
| 901 | * element of a jmp_buf, but C doesn't tell us the type of that. |
| 902 | */ |
| 903 | if (image->opaque != NULL && image->opaque->error_buf != NULL) |
| 904 | longjmp(png_control_jmp_buf(image->opaque), 1); |
| 905 | |
| 906 | /* Missing longjmp buffer, the following is to help debugging: */ |
| 907 | { |
| 908 | size_t pos = png_safecat(image->message, (sizeof image->message), 0, |
| 909 | "bad longjmp: "); |
| 910 | png_safecat(image->message, (sizeof image->message), pos, |
| 911 | error_message); |
| 912 | } |
| 913 | } |
| 914 | |
| 915 | /* Here on an internal programming error. */ |
| 916 | abort(); |
| 917 | } |
| 918 | |
| 919 | #ifdef PNG_WARNINGS_SUPPORTED |
| 920 | void /* PRIVATE */ PNGCBAPI |
| 921 | png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message) |
| 922 | { |
| 923 | const png_const_structrp png_ptr = png_nonconst_ptr; |
| 924 | png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); |
| 925 | |
| 926 | /* A warning is only logged if there is no prior warning or error. */ |
| 927 | if (image->warning_or_error == 0) |
| 928 | { |
| 929 | png_safecat(image->message, (sizeof image->message), 0, warning_message); |
| 930 | image->warning_or_error |= PNG_IMAGE_WARNING; |
| 931 | } |
| 932 | } |
| 933 | #endif |
| 934 | |
| 935 | int /* PRIVATE */ |
| 936 | png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg) |
| 937 | { |
| 938 | volatile png_imagep image = image_in; |
| 939 | volatile int result; |
| 940 | volatile png_voidp saved_error_buf; |
| 941 | jmp_buf safe_jmpbuf; |
| 942 | |
| 943 | /* Safely execute function(arg) with png_error returning to this function. */ |
| 944 | saved_error_buf = image->opaque->error_buf; |
| 945 | result = setjmp(safe_jmpbuf) == 0; |
| 946 | |
| 947 | if (result != 0) |
| 948 | { |
| 949 | |
| 950 | image->opaque->error_buf = safe_jmpbuf; |
| 951 | result = function(arg); |
| 952 | } |
| 953 | |
| 954 | image->opaque->error_buf = saved_error_buf; |
| 955 | |
| 956 | /* And do the cleanup prior to any failure return. */ |
| 957 | if (result == 0) |
| 958 | png_image_free(image); |
| 959 | |
| 960 | return result; |
| 961 | } |
| 962 | #endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */ |
| 963 | #endif /* READ || WRITE */ |