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
png_error(png_structp png_ptr,png_const_charp error_message)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
png_warning(png_structp png_ptr,png_const_charp warning_message)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 */
png_format_buffer(png_structp png_ptr,png_charp buffer,png_const_charp error_message)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
png_chunk_error(png_structp png_ptr,png_const_charp error_message)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
png_chunk_warning(png_structp png_ptr,png_const_charp warning_message)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 */
png_default_error(png_structp png_ptr,png_const_charp error_message)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 */
png_default_warning(png_structp png_ptr,png_const_charp warning_message)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
png_set_error_fn(png_structp png_ptr,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warning_fn)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
png_get_error_ptr(png_structp png_ptr)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
png_set_strip_error_numbers(png_structp png_ptr,png_uint_32 strip_mode)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