1 2 /* pngerror.c - stub functions for i/o and memory allocation 3 * 4 * Last changed in libpng 1.2.19 August 18, 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 void PNGAPI 35 png_error(png_structp png_ptr, png_const_charp error_message) 36 { 37 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 38 char msg[16]; 39 if (png_ptr != NULL) 40 { 41 if (png_ptr->flags& 42 (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) 43 { 44 if (*error_message == '#') 45 { 46 int offset; 47 for (offset=1; offset<15; offset++) 48 if (*(error_message+offset) == ' ') 49 break; 50 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT) 51 { 52 int i; 53 for (i=0; i<offset-1; i++) 54 msg[i]=error_message[i+1]; 55 msg[i]='\0'; 56 error_message=msg; 57 } 58 else 59 error_message+=offset; 60 } 61 else 62 { 63 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT) 64 { 65 msg[0]='0'; 66 msg[1]='\0'; 67 error_message=msg; 68 } 69 } 70 } 71 } 72 #endif 73 if (png_ptr != NULL && png_ptr->error_fn != NULL) 74 (*(png_ptr->error_fn))(png_ptr, error_message); 75 76 /* If the custom handler doesn't exist, or if it returns, 77 use the default handler, which will not return. */ 78 png_default_error(png_ptr, error_message); 79 } 80 81 #ifndef PNG_NO_WARNINGS 82 /* This function is called whenever there is a non-fatal error. This function 83 * should not be changed. If there is a need to handle warnings differently, 84 * you should supply a replacement warning function and use 85 * png_set_error_fn() to replace the warning function at run-time. 86 */ 87 void PNGAPI 88 png_warning(png_structp png_ptr, png_const_charp warning_message) 89 { 90 int offset = 0; 91 if (png_ptr != NULL) 92 { 93 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 94 if (png_ptr->flags& 95 (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) 96 #endif 97 { 98 if (*warning_message == '#') 99 { 100 for (offset=1; offset<15; offset++) 101 if (*(warning_message+offset) == ' ') 102 break; 103 } 104 } 105 if (png_ptr != NULL && png_ptr->warning_fn != NULL) 106 (*(png_ptr->warning_fn))(png_ptr, warning_message+offset); 107 } 108 else 109 png_default_warning(png_ptr, warning_message+offset); 110 } 111 #endif /* PNG_NO_WARNINGS */ 112 113 114 /* These utilities are used internally to build an error message that relates 115 * to the current chunk. The chunk name comes from png_ptr->chunk_name, 116 * this is used to prefix the message. The message is limited in length 117 * to 63 bytes, the name characters are output as hex digits wrapped in [] 118 * if the character is invalid. 119 */ 120 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) 121 static PNG_CONST char png_digit[16] = { 122 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 123 'A', 'B', 'C', 'D', 'E', 'F' 124 }; 125 126 static void /* PRIVATE */ 127 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp 128 error_message) 129 { 130 int iout = 0, iin = 0; 131 132 while (iin < 4) 133 { 134 int c = png_ptr->chunk_name[iin++]; 135 if (isnonalpha(c)) 136 { 137 buffer[iout++] = '['; 138 buffer[iout++] = png_digit[(c & 0xf0) >> 4]; 139 buffer[iout++] = png_digit[c & 0x0f]; 140 buffer[iout++] = ']'; 141 } 142 else 143 { 144 buffer[iout++] = (png_byte)c; 145 } 146 } 147 148 if (error_message == NULL) 149 buffer[iout] = 0; 150 else 151 { 152 buffer[iout++] = ':'; 153 buffer[iout++] = ' '; 154 png_strncpy(buffer+iout, error_message, 63); 155 buffer[iout+63] = 0; 156 } 157 } 158 159 #ifdef PNG_READ_SUPPORTED 160 void PNGAPI 161 png_chunk_error(png_structp png_ptr, png_const_charp error_message) 162 { 163 char msg[18+64]; 164 if (png_ptr == NULL) 165 png_error(png_ptr, error_message); 166 else 167 { 168 png_format_buffer(png_ptr, msg, error_message); 169 png_error(png_ptr, msg); 170 } 171 } 172 173 #ifndef PNG_NO_WARNINGS 174 void PNGAPI 175 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message) 176 { 177 char msg[18+64]; 178 if (png_ptr == NULL) 179 png_warning(png_ptr, warning_message); 180 else 181 { 182 png_format_buffer(png_ptr, msg, warning_message); 183 png_warning(png_ptr, msg); 184 } 185 } 186 #endif /* PNG_NO_WARNINGS */ 187 188 #endif /* PNG_READ_SUPPORTED */ 189 190 /* This is the default error handling function. Note that replacements for 191 * this function MUST NOT RETURN, or the program will likely crash. This 192 * function is used by default, or if the program supplies NULL for the 193 * error function pointer in png_set_error_fn(). 194 */ 195 static void /* PRIVATE */ 196 png_default_error(png_structp png_ptr, png_const_charp error_message) 197 { 198 #ifndef PNG_NO_CONSOLE_IO 199 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 200 if (*error_message == '#') 201 { 202 int offset; 203 char error_number[16]; 204 for (offset=0; offset<15; offset++) 205 { 206 error_number[offset] = *(error_message+offset+1); 207 if (*(error_message+offset) == ' ') 208 break; 209 } 210 if((offset > 1) && (offset < 15)) 211 { 212 error_number[offset-1]='\0'; 213 fprintf(stderr, "libpng error no. %s: %s\n", error_number, 214 error_message+offset); 215 } 216 else 217 fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset); 218 } 219 else 220 #endif 221 fprintf(stderr, "libpng error: %s\n", error_message); 222 #endif 223 224 #ifdef PNG_SETJMP_SUPPORTED 225 if (png_ptr) 226 { 227 # ifdef USE_FAR_KEYWORD 228 { 229 jmp_buf jmpbuf; 230 png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf)); 231 longjmp(jmpbuf, 1); 232 } 233 # else 234 longjmp(png_ptr->jmpbuf, 1); 235 # endif 236 } 237 #else 238 PNG_ABORT(); 239 #endif 240 #ifdef PNG_NO_CONSOLE_IO 241 error_message = error_message; /* make compiler happy */ 242 #endif 243 } 244 245 #ifndef PNG_NO_WARNINGS 246 /* This function is called when there is a warning, but the library thinks 247 * it can continue anyway. Replacement functions don't have to do anything 248 * here if you don't want them to. In the default configuration, png_ptr is 249 * not used, but it is passed in case it may be useful. 250 */ 251 static void /* PRIVATE */ 252 png_default_warning(png_structp png_ptr, png_const_charp warning_message) 253 { 254 #ifndef PNG_NO_CONSOLE_IO 255 # ifdef PNG_ERROR_NUMBERS_SUPPORTED 256 if (*warning_message == '#') 257 { 258 int offset; 259 char warning_number[16]; 260 for (offset=0; offset<15; offset++) 261 { 262 warning_number[offset]=*(warning_message+offset+1); 263 if (*(warning_message+offset) == ' ') 264 break; 265 } 266 if((offset > 1) && (offset < 15)) 267 { 268 warning_number[offset-1]='\0'; 269 fprintf(stderr, "libpng warning no. %s: %s\n", warning_number, 270 warning_message+offset); 271 } 272 else 273 fprintf(stderr, "libpng warning: %s\n", warning_message); 274 } 275 else 276 # endif 277 fprintf(stderr, "libpng warning: %s\n", warning_message); 278 #else 279 warning_message = warning_message; /* make compiler happy */ 280 #endif 281 png_ptr = png_ptr; /* make compiler happy */ 282 } 283 #endif /* PNG_NO_WARNINGS */ 284 285 /* This function is called when the application wants to use another method 286 * of handling errors and warnings. Note that the error function MUST NOT 287 * return to the calling routine or serious problems will occur. The return 288 * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) 289 */ 290 void PNGAPI 291 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, 292 png_error_ptr error_fn, png_error_ptr warning_fn) 293 { 294 if (png_ptr == NULL) 295 return; 296 png_ptr->error_ptr = error_ptr; 297 png_ptr->error_fn = error_fn; 298 png_ptr->warning_fn = warning_fn; 299 } 300 301 302 /* This function returns a pointer to the error_ptr associated with the user 303 * functions. The application should free any memory associated with this 304 * pointer before png_write_destroy and png_read_destroy are called. 305 */ 306 png_voidp PNGAPI 307 png_get_error_ptr(png_structp png_ptr) 308 { 309 if (png_ptr == NULL) 310 return NULL; 311 return ((png_voidp)png_ptr->error_ptr); 312 } 313 314 315 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 316 void PNGAPI 317 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode) 318 { 319 if(png_ptr != NULL) 320 { 321 png_ptr->flags &= 322 ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); 323 } 324 } 325 #endif 326 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ 327
