src/libpng/pngerror.c

   1
   2 /* pngerror.c - stub functions for i/o and memory allocation
   3  *
   4  * Last changed in libpng 1.2.37 [June 4, 2009]
   5  * For conditions of distribution and use, see copyright notice in png.h
   6  * Copyright (c) 1998-2009 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 error 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",
 233           error_number, error_message + offset + 1);
 234        fprintf(stderr, PNG_STRING_NEWLINE);
 235      }
 236      else
 237      {
 238        fprintf(stderr, "libpng error: %s, offset=%d",
 239           error_message, offset);
 240        fprintf(stderr, PNG_STRING_NEWLINE);
 241      }
 242    }
 243    else
 244 #endif
 245    {
 246       fprintf(stderr, "libpng error: %s", error_message);
 247       fprintf(stderr, PNG_STRING_NEWLINE);
 248    }
 249 #endif
 250
 251 #ifdef PNG_SETJMP_SUPPORTED
 252    if (png_ptr)
 253    {
 254 #  ifdef USE_FAR_KEYWORD
 255    {
 256       jmp_buf jmpbuf;
 257       png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 258       longjmp(jmpbuf, 1);
 259    }
 260 #  else
 261    longjmp(png_ptr->jmpbuf, 1);
 262 #  endif
 263    }
 264 #else
 265    PNG_ABORT();
 266 #endif
 267 #ifdef PNG_NO_CONSOLE_IO
 268    error_message = error_message; /* Make compiler happy */
 269 #endif
 270 }
 271
 272 #ifndef PNG_NO_WARNINGS
 273 /* This function is called when there is a warning, but the library thinks
 274  * it can continue anyway.  Replacement functions don't have to do anything
 275  * here if you don't want them to.  In the default configuration, png_ptr is
 276  * not used, but it is passed in case it may be useful.
 277  */
 278 static void /* PRIVATE */
 279 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 280 {
 281 #ifndef PNG_NO_CONSOLE_IO
 282 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 283    if (*warning_message == '#')
 284    {
 285      int offset;
 286      char warning_number[16];
 287      for (offset = 0; offset < 15; offset++)
 288      {
 289         warning_number[offset] = warning_message[offset + 1];
 290         if (warning_message[offset] == ' ')
 291             break;
 292      }
 293      if ((offset > 1) && (offset < 15))
 294      {
 295        warning_number[offset + 1] = '\0';
 296        fprintf(stderr, "libpng warning no. %s: %s",
 297           warning_number, warning_message + offset);
 298        fprintf(stderr, PNG_STRING_NEWLINE);
 299      }
 300      else
 301      {
 302        fprintf(stderr, "libpng warning: %s",
 303           warning_message);
 304        fprintf(stderr, PNG_STRING_NEWLINE);
 305      }
 306    }
 307    else
 308 #  endif
 309    {
 310      fprintf(stderr, "libpng warning: %s", warning_message);
 311      fprintf(stderr, PNG_STRING_NEWLINE);
 312    }
 313 #else
 314    warning_message = warning_message; /* Make compiler happy */
 315 #endif
 316    png_ptr = png_ptr; /* Make compiler happy */
 317 }
 318 #endif /* PNG_NO_WARNINGS */
 319
 320 /* This function is called when the application wants to use another method
 321  * of handling errors and warnings.  Note that the error function MUST NOT
 322  * return to the calling routine or serious problems will occur.  The return
 323  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 324  */
 325 void PNGAPI
 326 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 327    png_error_ptr error_fn, png_error_ptr warning_fn)
 328 {
 329    if (png_ptr == NULL)
 330       return;
 331    png_ptr->error_ptr = error_ptr;
 332    png_ptr->error_fn = error_fn;
 333    png_ptr->warning_fn = warning_fn;
 334 }
 335
 336
 337 /* This function returns a pointer to the error_ptr associated with the user
 338  * functions.  The application should free any memory associated with this
 339  * pointer before png_write_destroy and png_read_destroy are called.
 340  */
 341 png_voidp PNGAPI
 342 png_get_error_ptr(png_structp png_ptr)
 343 {
 344    if (png_ptr == NULL)
 345       return NULL;
 346    return ((png_voidp)png_ptr->error_ptr);
 347 }
 348
 349
 350 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 351 void PNGAPI
 352 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 353 {
 354    if (png_ptr != NULL)
 355    {
 356      png_ptr->flags &=
 357        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 358    }
 359 }
 360 #endif
 361 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */