1 /* exif-loader.c
2 *
3 * Copyright (c) 2002 Lutz Mueller <lutz@users.sourceforge.net>
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301 USA.
19 */
20
21 #include <config.h>
22
23 #include <libexif/exif-loader.h>
24 #include <libexif/exif-utils.h>
25 #include <libexif/i18n.h>
26
27 #include <sys/types.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <stdio.h>
31
32 #undef JPEG_MARKER_DHT
33 #define JPEG_MARKER_DHT 0xc4
34 #undef JPEG_MARKER_SOI
35 #define JPEG_MARKER_SOI 0xd8
36 #undef JPEG_MARKER_DQT
37 #define JPEG_MARKER_DQT 0xdb
38 #undef JPEG_MARKER_APP0
39 #define JPEG_MARKER_APP0 0xe0
40 #undef JPEG_MARKER_APP1
41 #define JPEG_MARKER_APP1 0xe1
42 #undef JPEG_MARKER_APP2
43 #define JPEG_MARKER_APP2 0xe2
44 #undef JPEG_MARKER_APP13
45 #define JPEG_MARKER_APP13 0xed
46 #undef JPEG_MARKER_COM
47 #define JPEG_MARKER_COM 0xfe
48
49 typedef enum {
50 EL_READ = 0,
51 EL_READ_SIZE_BYTE_24,
52 EL_READ_SIZE_BYTE_16,
53 EL_READ_SIZE_BYTE_08,
54 EL_READ_SIZE_BYTE_00,
55 EL_SKIP_BYTES,
56 EL_EXIF_FOUND,
57 } ExifLoaderState;
58
59 typedef enum {
60 EL_DATA_FORMAT_UNKNOWN,
61 EL_DATA_FORMAT_EXIF,
62 EL_DATA_FORMAT_JPEG,
63 EL_DATA_FORMAT_FUJI_RAW
64 } ExifLoaderDataFormat;
65
66 /*! \internal */
67 struct _ExifLoader {
68 ExifLoaderState state;
69 ExifLoaderDataFormat data_format;
70
71 /*! Small buffer used for detection of format */
72 unsigned char b[12];
73
74 /*! Number of bytes in the small buffer \c b */
75 unsigned char b_len;
76
77 unsigned int size;
78 unsigned char *buf;
79 unsigned int bytes_read;
80
81 unsigned int ref_count;
82
83 ExifLog *log;
84 ExifMem *mem;
85 };
86
87 /*! Magic number for EXIF header */
88 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
89
90 static void *
exif_loader_alloc(ExifLoader * l,unsigned int i)91 exif_loader_alloc (ExifLoader *l, unsigned int i)
92 {
93 void *d;
94
95 if (!l || !i)
96 return NULL;
97
98 d = exif_mem_alloc (l->mem, i);
99 if (d)
100 return d;
101
102 EXIF_LOG_NO_MEMORY (l->log, "ExifLog", i);
103 return NULL;
104 }
105
106 void
exif_loader_write_file(ExifLoader * l,const char * path)107 exif_loader_write_file (ExifLoader *l, const char *path)
108 {
109 FILE *f;
110 int size;
111 unsigned char data[1024];
112
113 if (!l)
114 return;
115
116 f = fopen (path, "rb");
117 if (!f) {
118 exif_log (l->log, EXIF_LOG_CODE_NONE, "ExifLoader",
119 _("The file '%s' could not be opened."), path);
120 return;
121 }
122 while (1) {
123 size = fread (data, 1, sizeof (data), f);
124 if (size <= 0)
125 break;
126 if (!exif_loader_write (l, data, size))
127 break;
128 }
129 fclose (f);
130 }
131
132 static unsigned int
exif_loader_copy(ExifLoader * eld,unsigned char * buf,unsigned int len)133 exif_loader_copy (ExifLoader *eld, unsigned char *buf, unsigned int len)
134 {
135 if (!eld || (len && !buf) || (eld->bytes_read >= eld->size))
136 return 0;
137
138 /* If needed, allocate the buffer. */
139 if (!eld->buf)
140 eld->buf = exif_loader_alloc (eld, eld->size);
141 if (!eld->buf)
142 return 0;
143
144 /* Copy memory */
145 len = MIN (len, eld->size - eld->bytes_read);
146 memcpy (eld->buf + eld->bytes_read, buf, len);
147 eld->bytes_read += len;
148
149 return (eld->bytes_read >= eld->size) ? 0 : 1;
150 }
151
152 unsigned char
exif_loader_write(ExifLoader * eld,unsigned char * buf,unsigned int len)153 exif_loader_write (ExifLoader *eld, unsigned char *buf, unsigned int len)
154 {
155 unsigned int i;
156
157 if (!eld || (len && !buf))
158 return 0;
159
160 switch (eld->state) {
161 case EL_EXIF_FOUND:
162 return exif_loader_copy (eld, buf, len);
163 case EL_SKIP_BYTES:
164 if (eld->size > len) {
165 eld->size -= len;
166 return 1;
167 }
168 len -= eld->size;
169 buf += eld->size;
170 eld->size = 0;
171 eld->b_len = 0;
172 switch (eld->data_format) {
173 case EL_DATA_FORMAT_FUJI_RAW:
174 eld->state = EL_READ_SIZE_BYTE_24;
175 break;
176 default:
177 eld->state = EL_READ;
178 break;
179 }
180 break;
181
182 case EL_READ:
183 default:
184 break;
185 }
186
187 if (!len)
188 return 1;
189 exif_log (eld->log, EXIF_LOG_CODE_DEBUG, "ExifLoader",
190 "Scanning %i byte(s) of data...", len);
191
192 /*
193 * First fill the small buffer. Only continue if the buffer
194 * is filled. Note that EXIF data contains at least 12 bytes.
195 */
196 i = MIN (len, sizeof (eld->b) - eld->b_len);
197 if (i) {
198 memcpy (&eld->b[eld->b_len], buf, i);
199 eld->b_len += i;
200 if (eld->b_len < sizeof (eld->b))
201 return 1;
202 buf += i;
203 len -= i;
204 }
205
206 switch (eld->data_format) {
207 case EL_DATA_FORMAT_UNKNOWN:
208
209 /* Check the small buffer against known formats. */
210 if (!memcmp (eld->b, "FUJIFILM", 8)) {
211
212 /* Skip to byte 84. There is another offset there. */
213 eld->data_format = EL_DATA_FORMAT_FUJI_RAW;
214 eld->size = 84;
215 eld->state = EL_SKIP_BYTES;
216 eld->size = 84;
217
218 } else if (!memcmp (eld->b + 2, ExifHeader, sizeof (ExifHeader))) {
219
220 /* Read the size (2 bytes). */
221 eld->data_format = EL_DATA_FORMAT_EXIF;
222 eld->state = EL_READ_SIZE_BYTE_08;
223 }
224 default:
225 break;
226 }
227
228 for (i = 0; i < sizeof (eld->b); i++)
229 switch (eld->state) {
230 case EL_EXIF_FOUND:
231 if (!exif_loader_copy (eld, eld->b + i,
232 sizeof (eld->b) - i))
233 return 0;
234 return exif_loader_copy (eld, buf, len);
235 case EL_SKIP_BYTES:
236 eld->size--;
237 if (!eld->size)
238 eld->state = EL_READ;
239 break;
240
241 case EL_READ_SIZE_BYTE_24:
242 eld->size |= eld->b[i] << 24;
243 eld->state = EL_READ_SIZE_BYTE_16;
244 break;
245 case EL_READ_SIZE_BYTE_16:
246 eld->size |= eld->b[i] << 16;
247 eld->state = EL_READ_SIZE_BYTE_08;
248 break;
249 case EL_READ_SIZE_BYTE_08:
250 eld->size |= eld->b[i] << 8;
251 eld->state = EL_READ_SIZE_BYTE_00;
252 break;
253 case EL_READ_SIZE_BYTE_00:
254 eld->size |= eld->b[i] << 0;
255 switch (eld->data_format) {
256 case EL_DATA_FORMAT_JPEG:
257 eld->state = EL_SKIP_BYTES;
258 eld->size -= 2;
259 break;
260 case EL_DATA_FORMAT_FUJI_RAW:
261 eld->data_format = EL_DATA_FORMAT_EXIF;
262 eld->state = EL_SKIP_BYTES;
263 eld->size -= 86;
264 break;
265 case EL_DATA_FORMAT_EXIF:
266 eld->state = EL_EXIF_FOUND;
267 break;
268 default:
269 break;
270 }
271 break;
272
273 default:
274 switch (eld->b[i]) {
275 case JPEG_MARKER_APP1:
276 if (!memcmp (eld->b + i + 3, ExifHeader, MIN((ssize_t)(sizeof(ExifHeader)), MAX(0, ((ssize_t)(sizeof(eld->b))) - ((ssize_t)i) - 3)))) {
277 eld->data_format = EL_DATA_FORMAT_EXIF;
278 } else {
279 eld->data_format = EL_DATA_FORMAT_JPEG; /* Probably JFIF - keep searching for APP1 EXIF*/
280 }
281 eld->size = 0;
282 eld->state = EL_READ_SIZE_BYTE_08;
283 break;
284 case JPEG_MARKER_DHT:
285 case JPEG_MARKER_DQT:
286 case JPEG_MARKER_APP0:
287 case JPEG_MARKER_APP2:
288 case JPEG_MARKER_APP13:
289 case JPEG_MARKER_COM:
290 eld->data_format = EL_DATA_FORMAT_JPEG;
291 eld->size = 0;
292 eld->state = EL_READ_SIZE_BYTE_08;
293 break;
294 case 0xff:
295 case JPEG_MARKER_SOI:
296 break;
297 default:
298 exif_log (eld->log,
299 EXIF_LOG_CODE_CORRUPT_DATA,
300 "ExifLoader", _("The data supplied "
301 "does not seem to contain "
302 "EXIF data."));
303 exif_loader_reset (eld);
304 return 0;
305 }
306 }
307
308 /*
309 * If we reach this point, the buffer has not been big enough
310 * to read all data we need. Fill it with new data.
311 */
312 eld->b_len = 0;
313 return exif_loader_write (eld, buf, len);
314 }
315
316 ExifLoader *
exif_loader_new(void)317 exif_loader_new (void)
318 {
319 ExifMem *mem = exif_mem_new_default ();
320 ExifLoader *l = exif_loader_new_mem (mem);
321
322 exif_mem_unref (mem);
323
324 return l;
325 }
326
327 ExifLoader *
exif_loader_new_mem(ExifMem * mem)328 exif_loader_new_mem (ExifMem *mem)
329 {
330 ExifLoader *loader;
331
332 if (!mem)
333 return NULL;
334
335 loader = exif_mem_alloc (mem, sizeof (ExifLoader));
336 if (!loader)
337 return NULL;
338 loader->ref_count = 1;
339
340 loader->mem = mem;
341 exif_mem_ref (mem);
342
343 return loader;
344 }
345
346 void
exif_loader_ref(ExifLoader * loader)347 exif_loader_ref (ExifLoader *loader)
348 {
349 if (loader)
350 loader->ref_count++;
351 }
352
353 static void
exif_loader_free(ExifLoader * loader)354 exif_loader_free (ExifLoader *loader)
355 {
356 ExifMem *mem;
357
358 if (!loader)
359 return;
360
361 mem = loader->mem;
362 exif_loader_reset (loader);
363 exif_log_unref (loader->log);
364 exif_mem_free (mem, loader);
365 exif_mem_unref (mem);
366 }
367
368 void
exif_loader_unref(ExifLoader * loader)369 exif_loader_unref (ExifLoader *loader)
370 {
371 if (!loader)
372 return;
373 if (!--loader->ref_count)
374 exif_loader_free (loader);
375 }
376
377 void
exif_loader_reset(ExifLoader * loader)378 exif_loader_reset (ExifLoader *loader)
379 {
380 if (!loader)
381 return;
382 exif_mem_free (loader->mem, loader->buf); loader->buf = NULL;
383 loader->size = 0;
384 loader->bytes_read = 0;
385 loader->state = 0;
386 loader->b_len = 0;
387 loader->data_format = EL_DATA_FORMAT_UNKNOWN;
388 }
389
390 ExifData *
exif_loader_get_data(ExifLoader * loader)391 exif_loader_get_data (ExifLoader *loader)
392 {
393 ExifData *ed;
394
395 if (!loader || (loader->data_format == EL_DATA_FORMAT_UNKNOWN) ||
396 !loader->bytes_read)
397 return NULL;
398
399 ed = exif_data_new_mem (loader->mem);
400 exif_data_log (ed, loader->log);
401 exif_data_load_data (ed, loader->buf, loader->bytes_read);
402
403 return ed;
404 }
405
406 void
exif_loader_get_buf(ExifLoader * loader,const unsigned char ** buf,unsigned int * buf_size)407 exif_loader_get_buf (ExifLoader *loader, const unsigned char **buf,
408 unsigned int *buf_size)
409 {
410 const unsigned char* b = NULL;
411 unsigned int s = 0;
412
413 if (!loader || (loader->data_format == EL_DATA_FORMAT_UNKNOWN)) {
414 exif_log (loader->log, EXIF_LOG_CODE_DEBUG, "ExifLoader",
415 "Loader format unknown");
416 } else {
417 b = loader->buf;
418 s = loader->bytes_read;
419 }
420 if (buf)
421 *buf = b;
422 if (buf_size)
423 *buf_size = s;
424 }
425
426 void
exif_loader_log(ExifLoader * loader,ExifLog * log)427 exif_loader_log (ExifLoader *loader, ExifLog *log)
428 {
429 if (!loader)
430 return;
431 exif_log_unref (loader->log);
432 loader->log = log;
433 exif_log_ref (log);
434 }
435