1
2/* pngerror.c - stub functions for i/o and memory allocation
3 *
4 * Last changed in libpng 1.2.22 [October 13, 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)
20static void /* PRIVATE */
21png_default_error PNGARG((png_structp png_ptr,
22 png_const_charp error_message));
23#ifndef PNG_NO_WARNINGS
24static void /* PRIVATE */
25png_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
35void PNGAPI
36png_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
82void PNGAPI
83png_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 */
100void PNGAPI
101png_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))
134static 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#define PNG_MAX_ERROR_TEXT 64
140
141#if !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT)
142static void /* PRIVATE */
143png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
144 error_message)
145{
146 int iout = 0, iin = 0;
147
148 while (iin < 4)
149 {
150 int c = png_ptr->chunk_name[iin++];
151 if (isnonalpha(c))
152 {
153 buffer[iout++] = '[';
154 buffer[iout++] = png_digit[(c & 0xf0) >> 4];
155 buffer[iout++] = png_digit[c & 0x0f];
156 buffer[iout++] = ']';
157 }
158 else
159 {
160 buffer[iout++] = (png_byte)c;
161 }
162 }
163
164 if (error_message == NULL)
165 buffer[iout] = '\0';
166 else
167 {
168 buffer[iout++] = ':';
169 buffer[iout++] = ' ';
170 png_memcpy(buffer+iout, error_message, PNG_MAX_ERROR_TEXT);
171 buffer[iout+PNG_MAX_ERROR_TEXT-1] = '\0';
172 }
173}
174
175#ifdef PNG_READ_SUPPORTED
176void PNGAPI
177png_chunk_error(png_structp png_ptr, png_const_charp error_message)
178{
179 char msg[18+PNG_MAX_ERROR_TEXT];
180 if (png_ptr == NULL)
181 png_error(png_ptr, error_message);
182 else
183 {
184 png_format_buffer(png_ptr, msg, error_message);
185 png_error(png_ptr, msg);
186 }
187}
188#endif /* PNG_READ_SUPPORTED */
189#endif /* !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT) */
190
191#ifndef PNG_NO_WARNINGS
192void PNGAPI
193png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
194{
195 char msg[18+PNG_MAX_ERROR_TEXT];
196 if (png_ptr == NULL)
197 png_warning(png_ptr, warning_message);
198 else
199 {
200 png_format_buffer(png_ptr, msg, warning_message);
201 png_warning(png_ptr, msg);
202 }
203}
204#endif /* PNG_NO_WARNINGS */
205
206
207/* This is the default error handling function. Note that replacements for
208 * this function MUST NOT RETURN, or the program will likely crash. This
209 * function is used by default, or if the program supplies NULL for the
210 * error function pointer in png_set_error_fn().
211 */
212static void /* PRIVATE */
213png_default_error(png_structp png_ptr, png_const_charp error_message)
214{
215#ifndef PNG_NO_CONSOLE_IO
216#ifdef PNG_ERROR_NUMBERS_SUPPORTED
217 if (*error_message == '#')
218 {
219 int offset;
220 char error_number[16];
221 for (offset=0; offset<15; offset++)
222 {
223 error_number[offset] = *(error_message+offset+1);
224 if (*(error_message+offset) == ' ')
225 break;
226 }
227 if((offset > 1) && (offset < 15))
228 {
229 error_number[offset-1]='\0';
230 fprintf(stderr, "libpng error no. %s: %s\n", error_number,
231 error_message+offset);
232 }
233 else
234 fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset);
235 }
236 else
237#endif
238 fprintf(stderr, "libpng error: %s\n", error_message);
239#endif
240
241#ifdef PNG_SETJMP_SUPPORTED
242 if (png_ptr)
243 {
244# ifdef USE_FAR_KEYWORD
245 {
246 jmp_buf jmpbuf;
247 png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
248 longjmp(jmpbuf, 1);
249 }
250# else
251 longjmp(png_ptr->jmpbuf, 1);
252# endif
253 }
254#else
255 PNG_ABORT();
256#endif
257#ifdef PNG_NO_CONSOLE_IO
258 error_message = error_message; /* make compiler happy */
259#endif
260}
261
262#ifndef PNG_NO_WARNINGS
263/* This function is called when there is a warning, but the library thinks
264 * it can continue anyway. Replacement functions don't have to do anything
265 * here if you don't want them to. In the default configuration, png_ptr is
266 * not used, but it is passed in case it may be useful.
267 */
268static void /* PRIVATE */
269png_default_warning(png_structp png_ptr, png_const_charp warning_message)
270{
271#ifndef PNG_NO_CONSOLE_IO
272# ifdef PNG_ERROR_NUMBERS_SUPPORTED
273 if (*warning_message == '#')
274 {
275 int offset;
276 char warning_number[16];
277 for (offset=0; offset<15; offset++)
278 {
279 warning_number[offset]=*(warning_message+offset+1);
280 if (*(warning_message+offset) == ' ')
281 break;
282 }
283 if((offset > 1) && (offset < 15))
284 {
285 warning_number[offset-1]='\0';
286 fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
287 warning_message+offset);
288 }
289 else
290 fprintf(stderr, "libpng warning: %s\n", warning_message);
291 }
292 else
293# endif
294 fprintf(stderr, "libpng warning: %s\n", warning_message);
295#else
296 warning_message = warning_message; /* make compiler happy */
297#endif
298 png_ptr = png_ptr; /* make compiler happy */
299}
300#endif /* PNG_NO_WARNINGS */
301
302/* This function is called when the application wants to use another method
303 * of handling errors and warnings. Note that the error function MUST NOT
304 * return to the calling routine or serious problems will occur. The return
305 * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
306 */
307void PNGAPI
308png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
309 png_error_ptr error_fn, png_error_ptr warning_fn)
310{
311 if (png_ptr == NULL)
312 return;
313 png_ptr->error_ptr = error_ptr;
314 png_ptr->error_fn = error_fn;
315 png_ptr->warning_fn = warning_fn;
316}
317
318
319/* This function returns a pointer to the error_ptr associated with the user
320 * functions. The application should free any memory associated with this
321 * pointer before png_write_destroy and png_read_destroy are called.
322 */
323png_voidp PNGAPI
324png_get_error_ptr(png_structp png_ptr)
325{
326 if (png_ptr == NULL)
327 return NULL;
328 return ((png_voidp)png_ptr->error_ptr);
329}
330
331
332#ifdef PNG_ERROR_NUMBERS_SUPPORTED
333void PNGAPI
334png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
335{
336 if(png_ptr != NULL)
337 {
338 png_ptr->flags &=
339 ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
340 }
341}
342#endif
343#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
344