src/png/pngerror.c

   1
   2 /* pngerror.c - stub functions for i/o and memory allocation
   3  *
   4  * Last changed in libpng 1.2.34 [December 18, 2008]
   5  * For conditions of distribution and use, see copyright notice in png.h
   6  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
   7  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   8  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   9  *
  10  * This file provides a location for all error handling.  Users who
  11  * need special error handling are expected to write replacement functions
  12  * and use png_set_error_fn() to use those functions.  See the instructions
  13  * at each function.
  14  */
  15
  16 #define PNG_INTERNAL
  17 #include "png.h"
  18 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
  19
  20 static void /* PRIVATE */
  21 png_default_error PNGARG((png_structp png_ptr,
  22   png_const_charp error_message));
  23 #ifndef PNG_NO_WARNINGS
  24 static void /* PRIVATE */
  25 png_default_warning PNGARG((png_structp png_ptr,
  26   png_const_charp warning_message));
  27 #endif /* PNG_NO_WARNINGS */
  28
  29 /* This function is called whenever there is a fatal error.  This function
  30  * should not be changed.  If there is a need to handle errors differently,
  31  * you should supply a replacement error function and use png_set_error_fn()
  32  * to replace the error function at run-time.
  33  */
  34 #ifndef PNG_NO_ERROR_TEXT
  35 void PNGAPI
  36 png_error(png_structp png_ptr, png_const_charp error_message)
  37 {
  38 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  39    char msg[16];
  40    if (png_ptr != NULL)
  41    {
  42      if (png_ptr->flags&
  43        (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
  44      {
  45        if (*error_message == '#')
  46        {
  47          /* Strip "#nnnn " from beginning of error message. */
  48            int offset;
  49            for (offset = 1; offset<15; offset++)
  50               if (error_message[offset] == ' ')
  51                   break;
  52            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  53            {
  54               int i;
  55               for (i = 0; i < offset - 1; i++)
  56                  msg[i] = error_message[i + 1];
  57               msg[i - 1] = '\0';
  58               error_message = msg;
  59            }
  60            else
  61               error_message += offset;
  62        }
  63        else
  64        {
  65            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  66            {
  67               msg[0] = '0';
  68               msg[1] = '\0';
  69               error_message = msg;
  70            }
  71        }
  72      }
  73    }
  74 #endif
  75    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  76       (*(png_ptr->error_fn))(png_ptr, error_message);
  77
  78    /* If the custom handler doesn't exist, or if it returns,
  79       use the default handler, which will not return. */
  80    png_default_error(png_ptr, error_message);
  81 }
  82 #else
  83 void PNGAPI
  84 png_err(png_structp png_ptr)
  85 {
  86    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  87       (*(png_ptr->error_fn))(png_ptr, '\0');
  88
  89    /* If the custom handler doesn't exist, or if it returns,
  90       use the default handler, which will not return. */
  91    png_default_error(png_ptr, '\0');
  92 }
  93 #endif /* PNG_NO_ERROR_TEXT */
  94
  95 #ifndef PNG_NO_WARNINGS
  96 /* This function is called whenever there is a non-fatal error.  This function
  97  * should not be changed.  If there is a need to handle warnings differently,
  98  * you should supply a replacement warning function and use
  99  * png_set_error_fn() to replace the warning function at run-time.
 100  */
 101 void PNGAPI
 102 png_warning(png_structp png_ptr, png_const_charp warning_message)
 103 {
 104    int offset = 0;
 105    if (png_ptr != NULL)
 106    {
 107 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 108    if (png_ptr->flags&
 109      (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
 110 #endif
 111      {
 112        if (*warning_message == '#')
 113        {
 114            for (offset = 1; offset < 15; offset++)
 115               if (warning_message[offset] == ' ')
 116                   break;
 117        }
 118      }
 119    }
 120    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
 121       (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
 122    else
 123       png_default_warning(png_ptr, warning_message + offset);
 124 }
 125 #endif /* PNG_NO_WARNINGS */
 126
 127
 128 /* These utilities are used internally to build an error message that relates
 129  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
 130  * this is used to prefix the message.  The message is limited in length
 131  * to 63 bytes, the name characters are output as hex digits wrapped in []
 132  * if the character is invalid.
 133  */
 134 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
 135 static PNG_CONST char png_digit[16] = {
 136    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 137    'A', 'B', 'C', 'D', 'E', 'F'
 138 };
 139
 140 #define PNG_MAX_ERROR_TEXT 64
 141
 142 #if !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT)
 143 static void /* PRIVATE */
 144 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 145    error_message)
 146 {
 147    int iout = 0, iin = 0;
 148
 149    while (iin < 4)
 150    {
 151       int c = png_ptr->chunk_name[iin++];
 152       if (isnonalpha(c))
 153       {
 154          buffer[iout++] = '[';
 155          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
 156          buffer[iout++] = png_digit[c & 0x0f];
 157          buffer[iout++] = ']';
 158       }
 159       else
 160       {
 161          buffer[iout++] = (png_byte)c;
 162       }
 163    }
 164
 165    if (error_message == NULL)
 166       buffer[iout] = '\0';
 167    else
 168    {
 169       buffer[iout++] = ':';
 170       buffer[iout++] = ' ';
 171       png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
 172       buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
 173    }
 174 }
 175
 176 #ifdef PNG_READ_SUPPORTED
 177 void PNGAPI
 178 png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 179 {
 180    char msg[18+PNG_MAX_ERROR_TEXT];
 181    if (png_ptr == NULL)
 182      png_error(png_ptr, error_message);
 183    else
 184    {
 185      png_format_buffer(png_ptr, msg, error_message);
 186      png_error(png_ptr, msg);
 187    }
 188 }
 189 #endif /* PNG_READ_SUPPORTED */
 190 #endif /* !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT) */
 191
 192 #ifndef PNG_NO_WARNINGS
 193 void PNGAPI
 194 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 195 {
 196    char msg[18+PNG_MAX_ERROR_TEXT];
 197    if (png_ptr == NULL)
 198      png_warning(png_ptr, warning_message);
 199    else
 200    {
 201      png_format_buffer(png_ptr, msg, warning_message);
 202      png_warning(png_ptr, msg);
 203    }
 204 }
 205 #endif /* PNG_NO_WARNINGS */
 206
 207
 208 /* This is the default error handling function.  Note that replacements for
 209  * this function MUST NOT RETURN, or the program will likely crash.  This
 210  * function is used by default, or if the program supplies NULL for the
 211  * error function pointer in png_set_error_fn().
 212  */
 213 static void /* PRIVATE */
 214 png_default_error(png_structp png_ptr, png_const_charp error_message)
 215 {
 216 #ifndef PNG_NO_CONSOLE_IO
 217 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 218    if (*error_message == '#')
 219    {
 220      /* Strip "#nnnn " from beginning of warning message. */
 221      int offset;
 222      char error_number[16];
 223      for (offset = 0; offset<15; offset++)
 224      {
 225          error_number[offset] = error_message[offset + 1];
 226          if (error_message[offset] == ' ')
 227              break;
 228      }
 229      if ((offset > 1) && (offset < 15))
 230      {
 231        error_number[offset - 1] = '\0';
 232        fprintf(stderr, "libpng error no. %s: %s\n", error_number,
 233           error_message + offset + 1);
 234      }
 235      else
 236        fprintf(stderr, "libpng error: %s, offset=%d\n", error_message, offset);
 237    }
 238    else
 239 #endif
 240    fprintf(stderr, "libpng error: %s\n", error_message);
 241 #endif
 242
 243 #ifdef PNG_SETJMP_SUPPORTED
 244    if (png_ptr)
 245    {
 246 #  ifdef USE_FAR_KEYWORD
 247    {
 248       jmp_buf jmpbuf;
 249       png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 250       longjmp(jmpbuf, 1);
 251    }
 252 #  else
 253    longjmp(png_ptr->jmpbuf, 1);
 254 #  endif
 255    }
 256 #else
 257    PNG_ABORT();
 258 #endif
 259 #ifdef PNG_NO_CONSOLE_IO
 260    error_message = error_message; /* make compiler happy */
 261 #endif
 262 }
 263
 264 #ifndef PNG_NO_WARNINGS
 265 /* This function is called when there is a warning, but the library thinks
 266  * it can continue anyway.  Replacement functions don't have to do anything
 267  * here if you don't want them to.  In the default configuration, png_ptr is
 268  * not used, but it is passed in case it may be useful.
 269  */
 270 static void /* PRIVATE */
 271 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 272 {
 273 #ifndef PNG_NO_CONSOLE_IO
 274 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 275    if (*warning_message == '#')
 276    {
 277      int offset;
 278      char warning_number[16];
 279      for (offset = 0; offset < 15; offset++)
 280      {
 281         warning_number[offset] = warning_message[offset + 1];
 282         if (warning_message[offset] == ' ')
 283             break;
 284      }
 285      if ((offset > 1) && (offset < 15))
 286      {
 287        warning_number[offset + 1] = '\0';
 288        fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
 289           warning_message + offset);
 290      }
 291      else
 292        fprintf(stderr, "libpng warning: %s\n", warning_message);
 293    }
 294    else
 295 #  endif
 296      fprintf(stderr, "libpng warning: %s\n", warning_message);
 297 #else
 298    warning_message = warning_message; /* make compiler happy */
 299 #endif
 300    png_ptr = png_ptr; /* make compiler happy */
 301 }
 302 #endif /* PNG_NO_WARNINGS */
 303
 304 /* This function is called when the application wants to use another method
 305  * of handling errors and warnings.  Note that the error function MUST NOT
 306  * return to the calling routine or serious problems will occur.  The return
 307  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 308  */
 309 void PNGAPI
 310 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 311    png_error_ptr error_fn, png_error_ptr warning_fn)
 312 {
 313    if (png_ptr == NULL)
 314       return;
 315    png_ptr->error_ptr = error_ptr;
 316    png_ptr->error_fn = error_fn;
 317    png_ptr->warning_fn = warning_fn;
 318 }
 319
 320
 321 /* This function returns a pointer to the error_ptr associated with the user
 322  * functions.  The application should free any memory associated with this
 323  * pointer before png_write_destroy and png_read_destroy are called.
 324  */
 325 png_voidp PNGAPI
 326 png_get_error_ptr(png_structp png_ptr)
 327 {
 328    if (png_ptr == NULL)
 329       return NULL;
 330    return ((png_voidp)png_ptr->error_ptr);
 331 }
 332
 333
 334 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 335 void PNGAPI
 336 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 337 {
 338    if (png_ptr != NULL)
 339    {
 340      png_ptr->flags &=
 341        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 342    }
 343 }
 344 #endif
 345 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */