src/png/pngerror.c

   1
   2 /* pngerror.c - stub functions for i/o and memory allocation
   3  *
   4  * Last changed in libpng 1.4.0 [January 3, 2010]
   5  * Copyright (c) 1998-2010 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 #define PNG_NO_PEDANTIC_WARNINGS
  20 #include "png.h"
  21 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
  22 #include "pngpriv.h"
  23
  24 static void /* PRIVATE */
  25 png_default_error PNGARG((png_structp png_ptr,
  26   png_const_charp error_message)) PNG_NORETURN;
  27 #ifdef PNG_WARNINGS_SUPPORTED
  28 static void /* PRIVATE */
  29 png_default_warning PNGARG((png_structp png_ptr,
  30   png_const_charp warning_message));
  31 #endif /* PNG_WARNINGS_SUPPORTED */
  32
  33 /* This function is called whenever there is a fatal error.  This function
  34  * should not be changed.  If there is a need to handle errors differently,
  35  * you should supply a replacement error function and use png_set_error_fn()
  36  * to replace the error function at run-time.
  37  */
  38 #ifdef PNG_ERROR_TEXT_SUPPORTED
  39 void PNGAPI
  40 png_error(png_structp png_ptr, png_const_charp error_message)
  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))
  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            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  57            {
  58               int i;
  59               for (i = 0; i < offset - 1; i++)
  60                  msg[i] = error_message[i + 1];
  61               msg[i - 1] = '\0';
  62               error_message = msg;
  63            }
  64            else
  65               error_message += offset;
  66        }
  67        else
  68        {
  69            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  70            {
  71               msg[0] = '0';
  72               msg[1] = '\0';
  73               error_message = msg;
  74            }
  75        }
  76      }
  77    }
  78 #endif
  79    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  80       (*(png_ptr->error_fn))(png_ptr, error_message);
  81
  82    /* If the custom handler doesn't exist, or if it returns,
  83       use the default handler, which will not return. */
  84    png_default_error(png_ptr, error_message);
  85 }
  86 #else
  87 void PNGAPI
  88 png_err(png_structp png_ptr)
  89 {
  90    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  91       (*(png_ptr->error_fn))(png_ptr, '\0');
  92
  93    /* If the custom handler doesn't exist, or if it returns,
  94       use the default handler, which will not return. */
  95    png_default_error(png_ptr, '\0');
  96 }
  97 #endif /* PNG_ERROR_TEXT_SUPPORTED */
  98
  99 #ifdef PNG_WARNINGS_SUPPORTED
 100 /* This function is called whenever there is a non-fatal error.  This function
 101  * should not be changed.  If there is a need to handle warnings differently,
 102  * you should supply a replacement warning function and use
 103  * png_set_error_fn() to replace the warning function at run-time.
 104  */
 105 void PNGAPI
 106 png_warning(png_structp png_ptr, png_const_charp warning_message)
 107 {
 108    int offset = 0;
 109    if (png_ptr != NULL)
 110    {
 111 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 112    if (png_ptr->flags&
 113      (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
 114 #endif
 115      {
 116        if (*warning_message == PNG_LITERAL_SHARP)
 117        {
 118            for (offset = 1; offset < 15; offset++)
 119               if (warning_message[offset] == ' ')
 120                   break;
 121        }
 122      }
 123    }
 124    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
 125       (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
 126    else
 127       png_default_warning(png_ptr, warning_message + offset);
 128 }
 129 #endif /* PNG_WARNINGS_SUPPORTED */
 130
 131 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 132 void PNGAPI
 133 png_benign_error(png_structp png_ptr, png_const_charp error_message)
 134 {
 135   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
 136     png_warning(png_ptr, error_message);
 137   else
 138     png_error(png_ptr, error_message);
 139 }
 140 #endif
 141
 142 /* These utilities are used internally to build an error message that relates
 143  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
 144  * this is used to prefix the message.  The message is limited in length
 145  * to 63 bytes, the name characters are output as hex digits wrapped in []
 146  * if the character is invalid.
 147  */
 148 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
 149 static PNG_CONST char png_digit[16] = {
 150    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 151    'A', 'B', 'C', 'D', 'E', 'F'
 152 };
 153
 154 #define PNG_MAX_ERROR_TEXT 64
 155 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
 156 static void /* PRIVATE */
 157 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 158    error_message)
 159 {
 160    int iout = 0, iin = 0;
 161
 162    while (iin < 4)
 163    {
 164       int c = png_ptr->chunk_name[iin++];
 165       if (isnonalpha(c))
 166       {
 167          buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
 168          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
 169          buffer[iout++] = png_digit[c & 0x0f];
 170          buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
 171       }
 172       else
 173       {
 174          buffer[iout++] = (png_byte)c;
 175       }
 176    }
 177
 178    if (error_message == NULL)
 179       buffer[iout] = '\0';
 180    else
 181    {
 182       buffer[iout++] = ':';
 183       buffer[iout++] = ' ';
 184       png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
 185       buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
 186    }
 187 }
 188
 189 #ifdef PNG_READ_SUPPORTED
 190 void PNGAPI
 191 png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 192 {
 193    char msg[18+PNG_MAX_ERROR_TEXT];
 194    if (png_ptr == NULL)
 195      png_error(png_ptr, error_message);
 196    else
 197    {
 198      png_format_buffer(png_ptr, msg, error_message);
 199      png_error(png_ptr, msg);
 200    }
 201 }
 202 #endif /* PNG_READ_SUPPORTED */
 203 #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
 204
 205 #ifdef PNG_WARNINGS_SUPPORTED
 206 void PNGAPI
 207 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 208 {
 209    char msg[18+PNG_MAX_ERROR_TEXT];
 210    if (png_ptr == NULL)
 211      png_warning(png_ptr, warning_message);
 212    else
 213    {
 214      png_format_buffer(png_ptr, msg, warning_message);
 215      png_warning(png_ptr, msg);
 216    }
 217 }
 218 #endif /* PNG_WARNINGS_SUPPORTED */
 219
 220 #ifdef PNG_READ_SUPPORTED
 221 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 222 void PNGAPI
 223 png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
 224 {
 225   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
 226     png_chunk_warning(png_ptr, error_message);
 227   else
 228     png_chunk_error(png_ptr, error_message);
 229 }
 230 #endif
 231 #endif /* PNG_READ_SUPPORTED */
 232
 233 #ifdef PNG_SETJMP_SUPPORTED
 234 /* This API only exists if ANSI-C style error handling is used,
 235  * otherwise it is necessary for png_default_error to be overridden.
 236  */
 237 jmp_buf* PNGAPI
 238 png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
 239     size_t jmp_buf_size)
 240 {
 241    if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf))
 242       return NULL;
 243
 244    png_ptr->longjmp_fn = longjmp_fn;
 245    return &png_ptr->jmpbuf;
 246 }
 247 #endif
 248
 249 /* This is the default error handling function.  Note that replacements for
 250  * this function MUST NOT RETURN, or the program will likely crash.  This
 251  * function is used by default, or if the program supplies NULL for the
 252  * error function pointer in png_set_error_fn().
 253  */
 254 static void /* PRIVATE */
 255 png_default_error(png_structp png_ptr, png_const_charp error_message)
 256 {
 257 #ifdef PNG_CONSOLE_IO_SUPPORTED
 258 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 259    if (*error_message == PNG_LITERAL_SHARP)
 260    {
 261      /* Strip "#nnnn " from beginning of error message. */
 262      int offset;
 263      char error_number[16];
 264      for (offset = 0; offset<15; offset++)
 265      {
 266          error_number[offset] = error_message[offset + 1];
 267          if (error_message[offset] == ' ')
 268              break;
 269      }
 270      if ((offset > 1) && (offset < 15))
 271      {
 272        error_number[offset - 1] = '\0';
 273        fprintf(stderr, "libpng error no. %s: %s",
 274           error_number, error_message + offset + 1);
 275        fprintf(stderr, PNG_STRING_NEWLINE);
 276      }
 277      else
 278      {
 279        fprintf(stderr, "libpng error: %s, offset=%d",
 280           error_message, offset);
 281        fprintf(stderr, PNG_STRING_NEWLINE);
 282      }
 283    }
 284    else
 285 #endif
 286    {
 287       fprintf(stderr, "libpng error: %s", error_message);
 288       fprintf(stderr, PNG_STRING_NEWLINE);
 289    }
 290 #endif
 291
 292 #ifdef PNG_SETJMP_SUPPORTED
 293    if (png_ptr && png_ptr->longjmp_fn)
 294    {
 295 #  ifdef USE_FAR_KEYWORD
 296    {
 297       jmp_buf jmpbuf;
 298       png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 299      png_ptr->longjmp_fn(jmpbuf, 1);
 300    }
 301 #  else
 302    png_ptr->longjmp_fn(png_ptr->jmpbuf, 1);
 303 #  endif
 304    }
 305 #endif
 306    /* Here if not setjmp support or if png_ptr is null. */
 307    PNG_ABORT();
 308 #ifndef PNG_CONSOLE_IO_SUPPORTED
 309    error_message = error_message; /* Make compiler happy */
 310 #endif
 311 }
 312
 313 #ifdef PNG_WARNINGS_SUPPORTED
 314 /* This function is called when there is a warning, but the library thinks
 315  * it can continue anyway.  Replacement functions don't have to do anything
 316  * here if you don't want them to.  In the default configuration, png_ptr is
 317  * not used, but it is passed in case it may be useful.
 318  */
 319 static void /* PRIVATE */
 320 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 321 {
 322 #ifdef PNG_CONSOLE_IO_SUPPORTED
 323 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 324    if (*warning_message == PNG_LITERAL_SHARP)
 325    {
 326      int offset;
 327      char warning_number[16];
 328      for (offset = 0; offset < 15; offset++)
 329      {
 330         warning_number[offset] = warning_message[offset + 1];
 331         if (warning_message[offset] == ' ')
 332             break;
 333      }
 334      if ((offset > 1) && (offset < 15))
 335      {
 336        warning_number[offset + 1] = '\0';
 337        fprintf(stderr, "libpng warning no. %s: %s",
 338           warning_number, warning_message + offset);
 339        fprintf(stderr, PNG_STRING_NEWLINE);
 340      }
 341      else
 342      {
 343        fprintf(stderr, "libpng warning: %s",
 344           warning_message);
 345        fprintf(stderr, PNG_STRING_NEWLINE);
 346      }
 347    }
 348    else
 349 #  endif
 350    {
 351      fprintf(stderr, "libpng warning: %s", warning_message);
 352      fprintf(stderr, PNG_STRING_NEWLINE);
 353    }
 354 #else
 355    warning_message = warning_message; /* Make compiler happy */
 356 #endif
 357    png_ptr = png_ptr; /* Make compiler happy */
 358 }
 359 #endif /* PNG_WARNINGS_SUPPORTED */
 360
 361 /* This function is called when the application wants to use another method
 362  * of handling errors and warnings.  Note that the error function MUST NOT
 363  * return to the calling routine or serious problems will occur.  The return
 364  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 365  */
 366 void PNGAPI
 367 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 368    png_error_ptr error_fn, png_error_ptr warning_fn)
 369 {
 370    if (png_ptr == NULL)
 371       return;
 372    png_ptr->error_ptr = error_ptr;
 373    png_ptr->error_fn = error_fn;
 374    png_ptr->warning_fn = warning_fn;
 375 }
 376
 377
 378 /* This function returns a pointer to the error_ptr associated with the user
 379  * functions.  The application should free any memory associated with this
 380  * pointer before png_write_destroy and png_read_destroy are called.
 381  */
 382 png_voidp PNGAPI
 383 png_get_error_ptr(png_structp png_ptr)
 384 {
 385    if (png_ptr == NULL)
 386       return NULL;
 387    return ((png_voidp)png_ptr->error_ptr);
 388 }
 389
 390
 391 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 392 void PNGAPI
 393 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 394 {
 395    if (png_ptr != NULL)
 396    {
 397      png_ptr->flags &=
 398        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 399    }
 400 }
 401 #endif
 402 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */