src/png/pngerror.c

   1
   2 /* pngerror.c - stub functions for i/o and memory allocation
   3  *
   4  * Last changed in libpng 1.2.20 September 8, 2007
   5  * For conditions of distribution and use, see copyright notice in png.h
   6  * Copyright (c) 1998-2007 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
  19 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
  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            int offset;
  48            for (offset=1; offset<15; offset++)
  49               if (*(error_message+offset) == ' ')
  50                   break;
  51            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  52            {
  53               int i;
  54               for (i=0; i<offset-1; i++)
  55                  msg[i]=error_message[i+1];
  56               msg[i]='\0';
  57               error_message=msg;
  58            }
  59            else
  60               error_message+=offset;
  61        }
  62        else
  63        {
  64            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  65            {
  66               msg[0]='0';
  67               msg[1]='\0';
  68               error_message=msg;
  69            }
  70        }
  71      }
  72    }
  73 #endif
  74    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  75       (*(png_ptr->error_fn))(png_ptr, error_message);
  76
  77    /* If the custom handler doesn't exist, or if it returns,
  78       use the default handler, which will not return. */
  79    png_default_error(png_ptr, error_message);
  80 }
  81 #else
  82 void PNGAPI
  83 png_err(png_structp png_ptr)
  84 {
  85    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  86       (*(png_ptr->error_fn))(png_ptr, '\0');
  87
  88    /* If the custom handler doesn't exist, or if it returns,
  89       use the default handler, which will not return. */
  90    png_default_error(png_ptr, '\0');
  91 }
  92 #endif /* PNG_NO_ERROR_TEXT */
  93
  94 #ifndef PNG_NO_WARNINGS
  95 /* This function is called whenever there is a non-fatal error.  This function
  96  * should not be changed.  If there is a need to handle warnings differently,
  97  * you should supply a replacement warning function and use
  98  * png_set_error_fn() to replace the warning function at run-time.
  99  */
 100 void PNGAPI
 101 png_warning(png_structp png_ptr, png_const_charp warning_message)
 102 {
 103    int offset = 0;
 104    if (png_ptr != NULL)
 105    {
 106 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 107    if (png_ptr->flags&
 108      (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
 109 #endif
 110      {
 111        if (*warning_message == '#')
 112        {
 113            for (offset=1; offset<15; offset++)
 114               if (*(warning_message+offset) == ' ')
 115                   break;
 116        }
 117      }
 118      if (png_ptr != NULL && png_ptr->warning_fn != NULL)
 119         (*(png_ptr->warning_fn))(png_ptr, warning_message+offset);
 120    }
 121    else
 122       png_default_warning(png_ptr, warning_message+offset);
 123 }
 124 #endif /* PNG_NO_WARNINGS */
 125
 126
 127 /* These utilities are used internally to build an error message that relates
 128  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
 129  * this is used to prefix the message.  The message is limited in length
 130  * to 63 bytes, the name characters are output as hex digits wrapped in []
 131  * if the character is invalid.
 132  */
 133 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
 134 static PNG_CONST char png_digit[16] = {
 135    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 136    'A', 'B', 'C', 'D', 'E', 'F'
 137 };
 138
 139 #if !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT)
 140 static void /* PRIVATE */
 141 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 142    error_message)
 143 {
 144    int iout = 0, iin = 0;
 145
 146    while (iin < 4)
 147    {
 148       int c = png_ptr->chunk_name[iin++];
 149       if (isnonalpha(c))
 150       {
 151          buffer[iout++] = '[';
 152          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
 153          buffer[iout++] = png_digit[c & 0x0f];
 154          buffer[iout++] = ']';
 155       }
 156       else
 157       {
 158          buffer[iout++] = (png_byte)c;
 159       }
 160    }
 161
 162    if (error_message == NULL)
 163       buffer[iout] = 0;
 164    else
 165    {
 166       buffer[iout++] = ':';
 167       buffer[iout++] = ' ';
 168       png_strncpy(buffer+iout, error_message, 63);
 169       buffer[iout+63] = 0;
 170    }
 171 }
 172
 173 #ifdef PNG_READ_SUPPORTED
 174 void PNGAPI
 175 png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 176 {
 177    char msg[18+64];
 178    if (png_ptr == NULL)
 179      png_error(png_ptr, error_message);
 180    else
 181    {
 182      png_format_buffer(png_ptr, msg, error_message);
 183      png_error(png_ptr, msg);
 184    }
 185 }
 186 #endif /* PNG_READ_SUPPORTED */
 187 #endif /* !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT) */
 188
 189 #ifndef PNG_NO_WARNINGS
 190 void PNGAPI
 191 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 192 {
 193    char msg[18+64];
 194    if (png_ptr == NULL)
 195      png_warning(png_ptr, warning_message);
 196    else
 197    {
 198      png_format_buffer(png_ptr, msg, warning_message);
 199      png_warning(png_ptr, msg);
 200    }
 201 }
 202 #endif /* PNG_NO_WARNINGS */
 203
 204
 205 /* This is the default error handling function.  Note that replacements for
 206  * this function MUST NOT RETURN, or the program will likely crash.  This
 207  * function is used by default, or if the program supplies NULL for the
 208  * error function pointer in png_set_error_fn().
 209  */
 210 static void /* PRIVATE */
 211 png_default_error(png_structp png_ptr, png_const_charp error_message)
 212 {
 213 #ifndef PNG_NO_CONSOLE_IO
 214 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 215    if (*error_message == '#')
 216    {
 217      int offset;
 218      char error_number[16];
 219      for (offset=0; offset<15; offset++)
 220      {
 221          error_number[offset] = *(error_message+offset+1);
 222          if (*(error_message+offset) == ' ')
 223              break;
 224      }
 225      if((offset > 1) && (offset < 15))
 226      {
 227        error_number[offset-1]='\0';
 228        fprintf(stderr, "libpng error no. %s: %s\n", error_number,
 229           error_message+offset);
 230      }
 231      else
 232        fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset);
 233    }
 234    else
 235 #endif
 236    fprintf(stderr, "libpng error: %s\n", error_message);
 237 #endif
 238
 239 #ifdef PNG_SETJMP_SUPPORTED
 240    if (png_ptr)
 241    {
 242 #  ifdef USE_FAR_KEYWORD
 243    {
 244       jmp_buf jmpbuf;
 245       png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 246       longjmp(jmpbuf, 1);
 247    }
 248 #  else
 249    longjmp(png_ptr->jmpbuf, 1);
 250 #  endif
 251    }
 252 #else
 253    PNG_ABORT();
 254 #endif
 255 #ifdef PNG_NO_CONSOLE_IO
 256    error_message = error_message; /* make compiler happy */
 257 #endif
 258 }
 259
 260 #ifndef PNG_NO_WARNINGS
 261 /* This function is called when there is a warning, but the library thinks
 262  * it can continue anyway.  Replacement functions don't have to do anything
 263  * here if you don't want them to.  In the default configuration, png_ptr is
 264  * not used, but it is passed in case it may be useful.
 265  */
 266 static void /* PRIVATE */
 267 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 268 {
 269 #ifndef PNG_NO_CONSOLE_IO
 270 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 271    if (*warning_message == '#')
 272    {
 273      int offset;
 274      char warning_number[16];
 275      for (offset=0; offset<15; offset++)
 276      {
 277         warning_number[offset]=*(warning_message+offset+1);
 278         if (*(warning_message+offset) == ' ')
 279             break;
 280      }
 281      if((offset > 1) && (offset < 15))
 282      {
 283        warning_number[offset-1]='\0';
 284        fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
 285           warning_message+offset);
 286      }
 287      else
 288        fprintf(stderr, "libpng warning: %s\n", warning_message);
 289    }
 290    else
 291 #  endif
 292      fprintf(stderr, "libpng warning: %s\n", warning_message);
 293 #else
 294    warning_message = warning_message; /* make compiler happy */
 295 #endif
 296    png_ptr = png_ptr; /* make compiler happy */
 297 }
 298 #endif /* PNG_NO_WARNINGS */
 299
 300 /* This function is called when the application wants to use another method
 301  * of handling errors and warnings.  Note that the error function MUST NOT
 302  * return to the calling routine or serious problems will occur.  The return
 303  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 304  */
 305 void PNGAPI
 306 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 307    png_error_ptr error_fn, png_error_ptr warning_fn)
 308 {
 309    if (png_ptr == NULL)
 310       return;
 311    png_ptr->error_ptr = error_ptr;
 312    png_ptr->error_fn = error_fn;
 313    png_ptr->warning_fn = warning_fn;
 314 }
 315
 316
 317 /* This function returns a pointer to the error_ptr associated with the user
 318  * functions.  The application should free any memory associated with this
 319  * pointer before png_write_destroy and png_read_destroy are called.
 320  */
 321 png_voidp PNGAPI
 322 png_get_error_ptr(png_structp png_ptr)
 323 {
 324    if (png_ptr == NULL)
 325       return NULL;
 326    return ((png_voidp)png_ptr->error_ptr);
 327 }
 328
 329
 330 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 331 void PNGAPI
 332 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 333 {
 334    if(png_ptr != NULL)
 335    {
 336      png_ptr->flags &=
 337        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 338    }
 339 }
 340 #endif
 341 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */