1 2/* pngerror.c - stub functions for i/o and memory allocation 3 * 4 * libpng version 1.2.7 - September 12, 2004 5 * For conditions of distribution and use, see copyright notice in png.h 6 * Copyright (c) 1998-2004 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 19static void /* PRIVATE */ 20png_default_error PNGARG((png_structp png_ptr, 21 png_const_charp error_message)); 22static void /* PRIVATE */ 23png_default_warning PNGARG((png_structp png_ptr, 24 png_const_charp warning_message)); 25 26/* This function is called whenever there is a fatal error. This function 27 * should not be changed. If there is a need to handle errors differently, 28 * you should supply a replacement error function and use png_set_error_fn() 29 * to replace the error function at run-time. 30 */ 31void PNGAPI 32png_error(png_structp png_ptr, png_const_charp error_message) 33{ 34#ifdef PNG_ERROR_NUMBERS_SUPPORTED 35 char msg[16]; 36 if (png_ptr->flags&(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) 37 { 38 if (*error_message == '#') 39 { 40 int offset; 41 for (offset=1; offset<15; offset++) 42 if (*(error_message+offset) == ' ') 43 break; 44 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT) 45 { 46 int i; 47 for (i=0; i<offset-1; i++) 48 msg[i]=error_message[i+1]; 49 msg[i]='\0'; 50 error_message=msg; 51 } 52 else 53 error_message+=offset; 54 } 55 else 56 { 57 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT) 58 { 59 msg[0]='0'; 60 msg[1]='\0'; 61 error_message=msg; 62 } 63 } 64 } 65#endif 66 if (png_ptr != NULL && png_ptr->error_fn != NULL) 67 (*(png_ptr->error_fn))(png_ptr, error_message); 68 69 /* If the custom handler doesn't exist, or if it returns, 70 use the default handler, which will not return. */ 71 png_default_error(png_ptr, error_message); 72} 73 74/* This function is called whenever there is a non-fatal error. This function 75 * should not be changed. If there is a need to handle warnings differently, 76 * you should supply a replacement warning function and use 77 * png_set_error_fn() to replace the warning function at run-time. 78 */ 79void PNGAPI 80png_warning(png_structp png_ptr, png_const_charp warning_message) 81{ 82 int offset = 0; 83#ifdef PNG_ERROR_NUMBERS_SUPPORTED 84 if (png_ptr->flags&(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) 85#endif 86 { 87 if (*warning_message == '#') 88 { 89 for (offset=1; offset<15; offset++) 90 if (*(warning_message+offset) == ' ') 91 break; 92 } 93 } 94 if (png_ptr != NULL && png_ptr->warning_fn != NULL) 95 (*(png_ptr->warning_fn))(png_ptr, warning_message+offset); 96 else 97 png_default_warning(png_ptr, warning_message+offset); 98} 99 100/* These utilities are used internally to build an error message that relates 101 * to the current chunk. The chunk name comes from png_ptr->chunk_name, 102 * this is used to prefix the message. The message is limited in length 103 * to 63 bytes, the name characters are output as hex digits wrapped in [] 104 * if the character is invalid. 105 */ 106#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) 107static PNG_CONST char png_digit[16] = { 108 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 109 'A', 'B', 'C', 'D', 'E', 'F' 110}; 111 112static void /* PRIVATE */ 113png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp 114 error_message) 115{ 116 int iout = 0, iin = 0; 117 118 while (iin < 4) 119 { 120 int c = png_ptr->chunk_name[iin++]; 121 if (isnonalpha(c)) 122 { 123 buffer[iout++] = '['; 124 buffer[iout++] = png_digit[(c & 0xf0) >> 4]; 125 buffer[iout++] = png_digit[c & 0x0f]; 126 buffer[iout++] = ']'; 127 } 128 else 129 { 130 buffer[iout++] = (png_byte)c; 131 } 132 } 133 134 if (error_message == NULL) 135 buffer[iout] = 0; 136 else 137 { 138 buffer[iout++] = ':'; 139 buffer[iout++] = ' '; 140 png_strncpy(buffer+iout, error_message, 63); 141 buffer[iout+63] = 0; 142 } 143} 144 145void PNGAPI 146png_chunk_error(png_structp png_ptr, png_const_charp error_message) 147{ 148 char msg[18+64]; 149 png_format_buffer(png_ptr, msg, error_message); 150 png_error(png_ptr, msg); 151} 152 153void PNGAPI 154png_chunk_warning(png_structp png_ptr, png_const_charp warning_message) 155{ 156 char msg[18+64]; 157 png_format_buffer(png_ptr, msg, warning_message); 158 png_warning(png_ptr, msg); 159} 160 161/* This is the default error handling function. Note that replacements for 162 * this function MUST NOT RETURN, or the program will likely crash. This 163 * function is used by default, or if the program supplies NULL for the 164 * error function pointer in png_set_error_fn(). 165 */ 166static void /* PRIVATE */ 167png_default_error(png_structp png_ptr, png_const_charp error_message) 168{ 169#ifndef PNG_NO_CONSOLE_IO 170#ifdef PNG_ERROR_NUMBERS_SUPPORTED 171 if (*error_message == '#') 172 { 173 int offset; 174 char error_number[16]; 175 for (offset=0; offset<15; offset++) 176 { 177 error_number[offset] = *(error_message+offset+1); 178 if (*(error_message+offset) == ' ') 179 break; 180 } 181 if((offset > 1) && (offset < 15)) 182 { 183 error_number[offset-1]='\0'; 184 fprintf(stderr, "libpng error no. %s: %s\n", error_number, 185 error_message+offset); 186 } 187 else 188 fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset); 189 } 190 else 191#endif 192 fprintf(stderr, "libpng error: %s\n", error_message); 193#endif 194 195#ifdef PNG_SETJMP_SUPPORTED 196# ifdef USE_FAR_KEYWORD 197 { 198 jmp_buf jmpbuf; 199 png_memcpy(jmpbuf,png_ptr->jmpbuf,png_sizeof(jmp_buf)); 200 longjmp(jmpbuf, 1); 201 } 202# else 203 longjmp(png_ptr->jmpbuf, 1); 204# endif 205#else 206 /* make compiler happy */ ; 207 if (png_ptr) 208 PNG_ABORT(); 209#endif 210#ifdef PNG_NO_CONSOLE_IO 211 /* make compiler happy */ ; 212 if (&error_message != NULL) 213 return; 214#endif 215} 216 217/* This function is called when there is a warning, but the library thinks 218 * it can continue anyway. Replacement functions don't have to do anything 219 * here if you don't want them to. In the default configuration, png_ptr is 220 * not used, but it is passed in case it may be useful. 221 */ 222static void /* PRIVATE */ 223png_default_warning(png_structp png_ptr, png_const_charp warning_message) 224{ 225#ifndef PNG_NO_CONSOLE_IO 226# ifdef PNG_ERROR_NUMBERS_SUPPORTED 227 if (*warning_message == '#') 228 { 229 int offset; 230 char warning_number[16]; 231 for (offset=0; offset<15; offset++) 232 { 233 warning_number[offset]=*(warning_message+offset+1); 234 if (*(warning_message+offset) == ' ') 235 break; 236 } 237 if((offset > 1) && (offset < 15)) 238 { 239 warning_number[offset-1]='\0'; 240 fprintf(stderr, "libpng warning no. %s: %s\n", warning_number, 241 warning_message+offset); 242 } 243 else 244 fprintf(stderr, "libpng warning: %s\n", warning_message); 245 } 246 else 247# endif 248 fprintf(stderr, "libpng warning: %s\n", warning_message); 249#else 250 /* make compiler happy */ ; 251 if (warning_message) 252 return; 253#endif 254 /* make compiler happy */ ; 255 if (png_ptr) 256 return; 257} 258 259/* This function is called when the application wants to use another method 260 * of handling errors and warnings. Note that the error function MUST NOT 261 * return to the calling routine or serious problems will occur. The return 262 * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) 263 */ 264void PNGAPI 265png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, 266 png_error_ptr error_fn, png_error_ptr warning_fn) 267{ 268 png_ptr->error_ptr = error_ptr; 269 png_ptr->error_fn = error_fn; 270 png_ptr->warning_fn = warning_fn; 271} 272 273 274/* This function returns a pointer to the error_ptr associated with the user 275 * functions. The application should free any memory associated with this 276 * pointer before png_write_destroy and png_read_destroy are called. 277 */ 278png_voidp PNGAPI 279png_get_error_ptr(png_structp png_ptr) 280{ 281 return ((png_voidp)png_ptr->error_ptr); 282} 283 284 285#ifdef PNG_ERROR_NUMBERS_SUPPORTED 286void PNGAPI 287png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode) 288{ 289 if(png_ptr != NULL) 290 { 291 png_ptr->flags &= 292 ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); 293 } 294} 295#endif 296