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1 /* exif-mnote-data-olympus.c
2  *
3  * Copyright (c) 2002, 2003 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 #include "exif-mnote-data-olympus.h"
23 
24 #include <stdlib.h>
25 #include <string.h>
26 #include <stdio.h>
27 
28 #include <libexif/exif-utils.h>
29 #include <libexif/exif-data.h>
30 
31 #define DEBUG
32 
33 /* Uncomment this to fix a problem with Sanyo MakerNotes. It's probably best
34  * not to in most cases because it seems to only affect the thumbnail tag
35  * which is duplicated in IFD 1, and fixing the offset could actually cause
36  * problems with other software that expects the broken form.
37  */
38 /*#define EXIF_OVERCOME_SANYO_OFFSET_BUG */
39 
40 static enum OlympusVersion
41 exif_mnote_data_olympus_identify_variant (const unsigned char *buf,
42 		unsigned int buf_size);
43 
44 
45 static void
exif_mnote_data_olympus_clear(ExifMnoteDataOlympus * n)46 exif_mnote_data_olympus_clear (ExifMnoteDataOlympus *n)
47 {
48 	ExifMnoteData *d = (ExifMnoteData *) n;
49 	unsigned int i;
50 
51 	if (!n) return;
52 
53 	if (n->entries) {
54 		for (i = 0; i < n->count; i++)
55 			if (n->entries[i].data) {
56 				exif_mem_free (d->mem, n->entries[i].data);
57 				n->entries[i].data = NULL;
58 			}
59 		exif_mem_free (d->mem, n->entries);
60 		n->entries = NULL;
61 		n->count = 0;
62 	}
63 }
64 
65 static void
exif_mnote_data_olympus_free(ExifMnoteData * n)66 exif_mnote_data_olympus_free (ExifMnoteData *n)
67 {
68 	if (!n) return;
69 
70 	exif_mnote_data_olympus_clear ((ExifMnoteDataOlympus *) n);
71 }
72 
73 static char *
exif_mnote_data_olympus_get_value(ExifMnoteData * d,unsigned int i,char * val,unsigned int maxlen)74 exif_mnote_data_olympus_get_value (ExifMnoteData *d, unsigned int i, char *val, unsigned int maxlen)
75 {
76 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) d;
77 
78 	if (!d || !val) return NULL;
79 	if (i > n->count -1) return NULL;
80 /*
81 	exif_log (d->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
82 		  "Querying value for tag '%s'...",
83 		  mnote_olympus_tag_get_name (n->entries[i].tag));
84 */
85 	return mnote_olympus_entry_get_value (&n->entries[i], val, maxlen);
86 }
87 
88 
89 
90 
91 /**
92  * @brief save the MnoteData from ne to buf
93  *
94  * @param ne extract the data from this structure
95  * @param *buf write the mnoteData to this buffer (buffer will be allocated)
96  * @param buf_size the size of the buffer
97  */
98 static void
exif_mnote_data_olympus_save(ExifMnoteData * ne,unsigned char ** buf,unsigned int * buf_size)99 exif_mnote_data_olympus_save (ExifMnoteData *ne,
100 		unsigned char **buf, unsigned int *buf_size)
101 {
102 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) ne;
103 	size_t i, o, s, doff, base = 0, o2 = 6 + 2;
104 	size_t datao = 0;
105 	unsigned char *t;
106 	size_t ts;
107 
108 	if (!n || !buf || !buf_size) return;
109 
110 	/*
111 	 * Allocate enough memory for all entries and the number of entries.
112 	 */
113 	*buf_size = 6 + 2 + 2 + n->count * 12;
114 	switch (n->version) {
115 	case olympusV1:
116 	case sanyoV1:
117 	case epsonV1:
118 		*buf = exif_mem_alloc (ne->mem, *buf_size);
119 		if (!*buf) {
120 			EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", *buf_size);
121 			return;
122 		}
123 
124 		/* Write the header and the number of entries. */
125 		strcpy ((char *)*buf, n->version==sanyoV1?"SANYO":
126 					(n->version==epsonV1?"EPSON":"OLYMP"));
127 		exif_set_short (*buf + 6, n->order, (ExifShort) 1);
128 		datao = n->offset;
129 		break;
130 
131 	case olympusV2:
132 		*buf_size += 8-6 + 4;
133 		*buf = exif_mem_alloc (ne->mem, *buf_size);
134 		if (!*buf) {
135 			EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", *buf_size);
136 			return;
137 		}
138 
139 		/* Write the header and the number of entries. */
140 		strcpy ((char *)*buf, "OLYMPUS");
141 		exif_set_short (*buf + 8, n->order, (ExifShort) (
142 			(n->order == EXIF_BYTE_ORDER_INTEL) ?
143 			('I' << 8) | 'I' :
144 			('M' << 8) | 'M'));
145 		exif_set_short (*buf + 10, n->order, (ExifShort) 3);
146 		o2 += 4;
147 		break;
148 
149 	case nikonV1:
150 		base = MNOTE_NIKON1_TAG_BASE;
151 
152 		/* v1 has offsets based to main IFD, not makernote IFD */
153 		datao += n->offset + 10;
154 		/* subtract the size here, so the increment in the next case will not harm us */
155 		*buf_size -= 8 + 2;
156 	/* Fall through to nikonV2 handler */
157 	case nikonV2:
158 	/* Write out V0 files in V2 format */
159 	case nikonV0:
160 		*buf_size += 8 + 2;
161 		*buf_size += 4; /* Next IFD pointer */
162 		*buf = exif_mem_alloc (ne->mem, *buf_size);
163 		if (!*buf) {
164 			EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", *buf_size);
165 			return;
166 		}
167 
168 		/* Write the header and the number of entries. */
169 		strcpy ((char *)*buf, "Nikon");
170 		(*buf)[6] = n->version;
171 
172 		if (n->version != nikonV1) {
173 			exif_set_short (*buf + 10, n->order, (ExifShort) (
174 				(n->order == EXIF_BYTE_ORDER_INTEL) ?
175 				('I' << 8) | 'I' :
176 				('M' << 8) | 'M'));
177 			exif_set_short (*buf + 12, n->order, (ExifShort) 0x2A);
178 			exif_set_long (*buf + 14, n->order, (ExifShort) 8);
179 			o2 += 2 + 8;
180 		}
181 		datao -= 10;
182 		/* Reset next IFD pointer */
183 		exif_set_long (*buf + o2 + 2 + n->count * 12, n->order, 0);
184 		break;
185 
186 	default:
187 		return;
188 	}
189 
190 	exif_set_short (*buf + o2, n->order, (ExifShort) n->count);
191 	o2 += 2;
192 
193 	/* Save each entry */
194 	for (i = 0; i < n->count; i++) {
195 		o = o2 + i * 12;
196 		exif_set_short (*buf + o + 0, n->order,
197 				(ExifShort) (n->entries[i].tag - base));
198 		exif_set_short (*buf + o + 2, n->order,
199 				(ExifShort) n->entries[i].format);
200 		exif_set_long  (*buf + o + 4, n->order,
201 				n->entries[i].components);
202 		o += 8;
203 		s = exif_format_get_size (n->entries[i].format) *
204 						n->entries[i].components;
205 		if (s > 65536) {
206 			/* Corrupt data: EXIF data size is limited to the
207 			 * maximum size of a JPEG segment (64 kb).
208 			 */
209 			continue;
210 		}
211 		if (s > 4) {
212 			doff = *buf_size;
213 			ts = *buf_size + s;
214 			t = exif_mem_realloc (ne->mem, *buf,
215 						 sizeof (char) * ts);
216 			if (!t) {
217 				EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", ts);
218 				return;
219 			}
220 			*buf = t;
221 			*buf_size = ts;
222 			exif_set_long (*buf + o, n->order, datao + doff);
223 		} else
224 			doff = o;
225 
226 		/* Write the data. */
227 		if (n->entries[i].data) {
228 			memcpy (*buf + doff, n->entries[i].data, s);
229 		} else {
230 			/* Most certainly damaged input file */
231 			memset (*buf + doff, 0, s);
232 		}
233 	}
234 }
235 
236 static void
exif_mnote_data_olympus_load(ExifMnoteData * en,const unsigned char * buf,unsigned int buf_size)237 exif_mnote_data_olympus_load (ExifMnoteData *en,
238 			      const unsigned char *buf, unsigned int buf_size)
239 {
240 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) en;
241 	ExifShort c;
242 	size_t i, tcount, o, o2, datao = 6, base = 0;
243 
244 	if (!n || !buf || !buf_size) {
245 		exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
246 			  "ExifMnoteDataOlympus", "Short MakerNote");
247 		return;
248 	}
249 	o2 = 6 + n->offset; /* Start of interesting data */
250 	if ((o2 + 10 < o2) || (o2 + 10 < 10) || (o2 + 10 > buf_size)) {
251 		exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
252 			  "ExifMnoteDataOlympus", "Short MakerNote");
253 		return;
254 	}
255 
256 	/*
257 	 * Olympus headers start with "OLYMP" and need to have at least
258 	 * a size of 22 bytes (6 for 'OLYMP', 2 other bytes, 2 for the
259 	 * number of entries, and 12 for one entry.
260 	 *
261 	 * Sanyo format is identical and uses identical tags except that
262 	 * header starts with "SANYO".
263 	 *
264 	 * Epson format is identical and uses identical tags except that
265 	 * header starts with "EPSON".
266 	 *
267 	 * Nikon headers start with "Nikon" (6 bytes including '\0'),
268 	 * version number (1 or 2).
269 	 *
270 	 * Version 1 continues with 0, 1, 0, number_of_tags,
271 	 * or just with number_of_tags (models D1H, D1X...).
272 	 *
273 	 * Version 2 continues with an unknown byte (0 or 10),
274 	 * two unknown bytes (0), "MM" or "II", another byte 0 and
275 	 * lastly 0x2A.
276 	 */
277 	n->version = exif_mnote_data_olympus_identify_variant(buf+o2, buf_size-o2);
278 	switch (n->version) {
279 	case olympusV1:
280 	case sanyoV1:
281 	case epsonV1:
282 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
283 			"Parsing Olympus/Sanyo/Epson maker note v1...");
284 
285 		/* The number of entries is at position 8. */
286 		if (buf[o2 + 6] == 1)
287 			n->order = EXIF_BYTE_ORDER_INTEL;
288 		else if (buf[o2 + 6 + 1] == 1)
289 			n->order = EXIF_BYTE_ORDER_MOTOROLA;
290 		o2 += 8;
291 		if (o2 + 2 > buf_size) return;
292 		c = exif_get_short (buf + o2, n->order);
293 		if ((!(c & 0xFF)) && (c > 0x500)) {
294 			if (n->order == EXIF_BYTE_ORDER_INTEL) {
295 				n->order = EXIF_BYTE_ORDER_MOTOROLA;
296 			} else {
297 				n->order = EXIF_BYTE_ORDER_INTEL;
298 			}
299 		}
300 		break;
301 
302 	case olympusV2:
303 		/* Olympus S760, S770 */
304 		datao = o2;
305 		o2 += 8;
306 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
307 			"Parsing Olympus maker note v2 (0x%02x, %02x, %02x, %02x)...",
308 			buf[o2], buf[o2 + 1], buf[o2 + 2], buf[o2 + 3]);
309 
310 		if ((buf[o2] == 'I') && (buf[o2 + 1] == 'I'))
311 			n->order = EXIF_BYTE_ORDER_INTEL;
312 		else if ((buf[o2] == 'M') && (buf[o2 + 1] == 'M'))
313 			n->order = EXIF_BYTE_ORDER_MOTOROLA;
314 
315 		/* The number of entries is at position 8+4. */
316 		o2 += 4;
317 		break;
318 
319 	case nikonV1:
320 		o2 += 6;
321 		if (o2 >= buf_size) return;
322 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
323 			"Parsing Nikon maker note v1 (0x%02x, %02x, %02x, "
324 			"%02x, %02x, %02x, %02x, %02x)...",
325 			buf[o2 + 0], buf[o2 + 1], buf[o2 + 2], buf[o2 + 3],
326 			buf[o2 + 4], buf[o2 + 5], buf[o2 + 6], buf[o2 + 7]);
327 
328 		/* Skip version number */
329 		o2 += 1;
330 
331 		/* Skip an unknown byte (00 or 0A). */
332 		o2 += 1;
333 
334 		base = MNOTE_NIKON1_TAG_BASE;
335 		/* Fix endianness, if needed */
336 		if (o2 + 2 > buf_size) return;
337 		c = exif_get_short (buf + o2, n->order);
338 		if ((!(c & 0xFF)) && (c > 0x500)) {
339 			if (n->order == EXIF_BYTE_ORDER_INTEL) {
340 				n->order = EXIF_BYTE_ORDER_MOTOROLA;
341 			} else {
342 				n->order = EXIF_BYTE_ORDER_INTEL;
343 			}
344 		}
345 		break;
346 
347 	case nikonV2:
348 		o2 += 6;
349 		if (o2 >= buf_size) return;
350 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
351 			"Parsing Nikon maker note v2 (0x%02x, %02x, %02x, "
352 			"%02x, %02x, %02x, %02x, %02x)...",
353 			buf[o2 + 0], buf[o2 + 1], buf[o2 + 2], buf[o2 + 3],
354 			buf[o2 + 4], buf[o2 + 5], buf[o2 + 6], buf[o2 + 7]);
355 
356 		/* Skip version number */
357 		o2 += 1;
358 
359 		/* Skip an unknown byte (00 or 0A). */
360 		o2 += 1;
361 
362 		/* Skip 2 unknown bytes (00 00). */
363 		o2 += 2;
364 
365 		/*
366 		 * Byte order. From here the data offset
367 		 * gets calculated.
368 		 */
369 		datao = o2;
370 		if (o2 >= buf_size) return;
371 		if (!strncmp ((char *)&buf[o2], "II", 2))
372 			n->order = EXIF_BYTE_ORDER_INTEL;
373 		else if (!strncmp ((char *)&buf[o2], "MM", 2))
374 			n->order = EXIF_BYTE_ORDER_MOTOROLA;
375 		else {
376 			exif_log (en->log, EXIF_LOG_CODE_DEBUG,
377 				"ExifMnoteDataOlympus", "Unknown "
378 				"byte order '%c%c'", buf[o2],
379 				buf[o2 + 1]);
380 			return;
381 		}
382 		o2 += 2;
383 
384 		/* Skip 2 unknown bytes (00 2A). */
385 		o2 += 2;
386 
387 		/* Go to where the number of entries is. */
388 		if (o2 + 4 > buf_size) return;
389 		o2 = datao + exif_get_long (buf + o2, n->order);
390 		break;
391 
392 	case nikonV0:
393 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
394 			"Parsing Nikon maker note v0 (0x%02x, %02x, %02x, "
395 			"%02x, %02x, %02x, %02x, %02x)...",
396 			buf[o2 + 0], buf[o2 + 1], buf[o2 + 2], buf[o2 + 3],
397 			buf[o2 + 4], buf[o2 + 5], buf[o2 + 6], buf[o2 + 7]);
398 		/* 00 1b is # of entries in Motorola order - the rest should also be in MM order */
399 		n->order = EXIF_BYTE_ORDER_MOTOROLA;
400 		break;
401 
402 	default:
403 		exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataOlympus",
404 			"Unknown Olympus variant %i.", n->version);
405 		return;
406 	}
407 
408 	/* Sanity check the offset */
409 	if ((o2 + 2 < o2) || (o2 + 2 < 2) || (o2 + 2 > buf_size)) {
410 		exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
411 			  "ExifMnoteOlympus", "Short MakerNote");
412 		return;
413 	}
414 
415 	/* Read the number of tags */
416 	c = exif_get_short (buf + o2, n->order);
417 	o2 += 2;
418 
419 	/* Remove any old entries */
420 	exif_mnote_data_olympus_clear (n);
421 
422 	/* Reserve enough space for all the possible MakerNote tags */
423 	n->entries = exif_mem_alloc (en->mem, sizeof (MnoteOlympusEntry) * c);
424 	if (!n->entries) {
425 		EXIF_LOG_NO_MEMORY(en->log, "ExifMnoteOlympus", sizeof (MnoteOlympusEntry) * c);
426 		return;
427 	}
428 
429 	/* Parse all c entries, storing ones that are successfully parsed */
430 	tcount = 0;
431 	for (i = c, o = o2; i; --i, o += 12) {
432 		size_t s;
433 		if ((o + 12 < o) || (o + 12 < 12) || (o + 12 > buf_size)) {
434 			exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
435 				  "ExifMnoteOlympus", "Short MakerNote");
436 			break;
437 		}
438 
439 	    n->entries[tcount].tag        = exif_get_short (buf + o, n->order) + base;
440 	    n->entries[tcount].format     = exif_get_short (buf + o + 2, n->order);
441 	    n->entries[tcount].components = exif_get_long (buf + o + 4, n->order);
442 	    n->entries[tcount].order      = n->order;
443 
444 	    exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteOlympus",
445 		      "Loading entry 0x%x ('%s')...", n->entries[tcount].tag,
446 		      mnote_olympus_tag_get_name (n->entries[tcount].tag));
447 /*	    exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteOlympus",
448 			    "0x%x %d %ld*(%d)",
449 		    n->entries[tcount].tag,
450 		    n->entries[tcount].format,
451 		    n->entries[tcount].components,
452 		    (int)exif_format_get_size(n->entries[tcount].format)); */
453 
454 	    /*
455 	     * Size? If bigger than 4 bytes, the actual data is not
456 	     * in the entry but somewhere else (offset).
457 	     */
458 	    s = exif_format_get_size (n->entries[tcount].format) *
459 		   			 n->entries[tcount].components;
460 		n->entries[tcount].size = s;
461 		if (s) {
462 			size_t dataofs = o + 8;
463 			if (s > 4) {
464 				/* The data in this case is merely a pointer */
465 				dataofs = exif_get_long (buf + dataofs, n->order) + datao;
466 #ifdef EXIF_OVERCOME_SANYO_OFFSET_BUG
467 				/* Some Sanyo models (e.g. VPC-C5, C40) suffer from a bug when
468 				 * writing the offset for the MNOTE_OLYMPUS_TAG_THUMBNAILIMAGE
469 				 * tag in its MakerNote. The offset is actually the absolute
470 				 * position in the file instead of the position within the IFD.
471 				 */
472 			    if (dataofs + s > buf_size && n->version == sanyoV1) {
473 					/* fix pointer */
474 					dataofs -= datao + 6;
475 					exif_log (en->log, EXIF_LOG_CODE_DEBUG,
476 						  "ExifMnoteOlympus",
477 						  "Inconsistent thumbnail tag offset; attempting to recover");
478 			    }
479 #endif
480 			}
481 			if ((dataofs + s < dataofs) || (dataofs + s < s) ||
482 			    (dataofs + s > buf_size)) {
483 				exif_log (en->log, EXIF_LOG_CODE_DEBUG,
484 					  "ExifMnoteOlympus",
485 					  "Tag data past end of buffer (%zu > %u)",
486 					  dataofs + s, buf_size);
487 				continue;
488 			}
489 
490 			n->entries[tcount].data = exif_mem_alloc (en->mem, s);
491 			if (!n->entries[tcount].data) {
492 				EXIF_LOG_NO_MEMORY(en->log, "ExifMnoteOlympus", s);
493 				continue;
494 			}
495 			memcpy (n->entries[tcount].data, buf + dataofs, s);
496 		}
497 
498 		/* Tag was successfully parsed */
499 		++tcount;
500 	}
501 	/* Store the count of successfully parsed tags */
502 	n->count = tcount;
503 }
504 
505 static unsigned int
exif_mnote_data_olympus_count(ExifMnoteData * n)506 exif_mnote_data_olympus_count (ExifMnoteData *n)
507 {
508 	return n ? ((ExifMnoteDataOlympus *) n)->count : 0;
509 }
510 
511 static unsigned int
exif_mnote_data_olympus_get_id(ExifMnoteData * d,unsigned int n)512 exif_mnote_data_olympus_get_id (ExifMnoteData *d, unsigned int n)
513 {
514 	ExifMnoteDataOlympus *note = (ExifMnoteDataOlympus *) d;
515 
516 	if (!note) return 0;
517 	if (note->count <= n) return 0;
518 	return note->entries[n].tag;
519 }
520 
521 static const char *
exif_mnote_data_olympus_get_name(ExifMnoteData * d,unsigned int i)522 exif_mnote_data_olympus_get_name (ExifMnoteData *d, unsigned int i)
523 {
524 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) d;
525 
526 	if (!n) return NULL;
527 	if (i >= n->count) return NULL;
528 	return mnote_olympus_tag_get_name (n->entries[i].tag);
529 }
530 
531 static const char *
exif_mnote_data_olympus_get_title(ExifMnoteData * d,unsigned int i)532 exif_mnote_data_olympus_get_title (ExifMnoteData *d, unsigned int i)
533 {
534 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) d;
535 
536 	if (!n) return NULL;
537 	if (i >= n->count) return NULL;
538         return mnote_olympus_tag_get_title (n->entries[i].tag);
539 }
540 
541 static const char *
exif_mnote_data_olympus_get_description(ExifMnoteData * d,unsigned int i)542 exif_mnote_data_olympus_get_description (ExifMnoteData *d, unsigned int i)
543 {
544 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) d;
545 
546 	if (!n) return NULL;
547 	if (i >= n->count) return NULL;
548         return mnote_olympus_tag_get_description (n->entries[i].tag);
549 }
550 
551 static void
exif_mnote_data_olympus_set_byte_order(ExifMnoteData * d,ExifByteOrder o)552 exif_mnote_data_olympus_set_byte_order (ExifMnoteData *d, ExifByteOrder o)
553 {
554 	ExifByteOrder o_orig;
555 	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) d;
556 	unsigned int i;
557 
558 	if (!n) return;
559 
560 	o_orig = n->order;
561 	n->order = o;
562 	for (i = 0; i < n->count; i++) {
563 		n->entries[i].order = o;
564 		exif_array_set_byte_order (n->entries[i].format, n->entries[i].data,
565 				n->entries[i].components, o_orig, o);
566 	}
567 }
568 
569 static void
exif_mnote_data_olympus_set_offset(ExifMnoteData * n,unsigned int o)570 exif_mnote_data_olympus_set_offset (ExifMnoteData *n, unsigned int o)
571 {
572 	if (n) ((ExifMnoteDataOlympus *) n)->offset = o;
573 }
574 
575 static enum OlympusVersion
exif_mnote_data_olympus_identify_variant(const unsigned char * buf,unsigned int buf_size)576 exif_mnote_data_olympus_identify_variant (const unsigned char *buf,
577 		unsigned int buf_size)
578 {
579 	/* Olympus, Nikon, Sanyo, Epson */
580 	if (buf_size >= 8) {
581 		/* Match the terminating NUL character, too */
582 		if (!memcmp (buf, "OLYMPUS", 8))
583 			   return olympusV2;
584 		else if (!memcmp (buf, "OLYMP", 6))
585 			   return olympusV1;
586 		else if (!memcmp (buf, "SANYO", 6))
587 			   return sanyoV1;
588 		else if (!memcmp (buf, "EPSON", 6))
589 			   return epsonV1;
590 		else if (!memcmp (buf, "Nikon", 6)) {
591 			switch (buf[6]) {
592 				case 1:  return nikonV1;
593 				case 2:  return nikonV2;
594 				default: return 0; /* Unrecognized Nikon variant */
595 			}
596 		}
597 	}
598 
599 	/* Another variant of Nikon */
600 	if ((buf_size >= 2) && (buf[0] == 0x00) && (buf[1] == 0x1b)) {
601 		return nikonV0;
602 	}
603 
604 	return unrecognized;
605 }
606 
607 int
exif_mnote_data_olympus_identify(const ExifData * ed,const ExifEntry * e)608 exif_mnote_data_olympus_identify (const ExifData *ed, const ExifEntry *e)
609 {
610 	int variant = exif_mnote_data_olympus_identify_variant(e->data, e->size);
611 
612 	if (variant == nikonV0) {
613 		/* This variant needs some extra checking with the Make */
614 		char value[5];
615 		ExifEntry *em = exif_data_get_entry (ed, EXIF_TAG_MAKE);
616 		variant = unrecognized;
617 
618 		if (em) {
619 			const char *v = exif_entry_get_value (em, value, sizeof(value));
620 			if (v && (!strncmp (v, "Nikon", sizeof(value)) ||
621 					  !strncmp (v, "NIKON", sizeof(value)) ))
622 				/* When saved, this variant will be written out like the
623 				 * alternative nikonV2 form above instead
624 				 */
625 				variant = nikonV0;
626 		}
627 	}
628 
629 	return variant;
630 }
631 
632 
633 ExifMnoteData *
exif_mnote_data_olympus_new(ExifMem * mem)634 exif_mnote_data_olympus_new (ExifMem *mem)
635 {
636 	ExifMnoteData *d;
637 
638 	if (!mem) return NULL;
639 
640 	d = exif_mem_alloc (mem, sizeof (ExifMnoteDataOlympus));
641 	if (!d) return NULL;
642 
643 	exif_mnote_data_construct (d, mem);
644 
645 	/* Set up function pointers */
646 	d->methods.free            = exif_mnote_data_olympus_free;
647 	d->methods.set_byte_order  = exif_mnote_data_olympus_set_byte_order;
648 	d->methods.set_offset      = exif_mnote_data_olympus_set_offset;
649 	d->methods.load            = exif_mnote_data_olympus_load;
650 	d->methods.save            = exif_mnote_data_olympus_save;
651 	d->methods.count           = exif_mnote_data_olympus_count;
652 	d->methods.get_id          = exif_mnote_data_olympus_get_id;
653 	d->methods.get_name        = exif_mnote_data_olympus_get_name;
654 	d->methods.get_title       = exif_mnote_data_olympus_get_title;
655 	d->methods.get_description = exif_mnote_data_olympus_get_description;
656 	d->methods.get_value       = exif_mnote_data_olympus_get_value;
657 
658 	return d;
659 }
660