1 /*-
2  * Copyright (c) 2008 Anselm Strauss
3  * Copyright (c) 2009 Joerg Sonnenberger
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  * Development supported by Google Summer of Code 2008.
29  */
30 
31 /*
32  * The current implementation is very limited:
33  *
34  *   - No encryption support.
35  *   - No ZIP64 support.
36  *   - No support for splitting and spanning.
37  *   - Only supports regular file and folder entries.
38  *
39  * Note that generally data in ZIP files is little-endian encoded,
40  * with some exceptions.
41  *
42  * TODO: Since Libarchive is generally 64bit oriented, but this implementation
43  * does not yet support sizes exceeding 32bit, it is highly fragile for
44  * big archives. This should change when ZIP64 is finally implemented, otherwise
45  * some serious checking has to be done.
46  *
47  */
48 
49 #include "archive_platform.h"
50 __FBSDID("$FreeBSD: head/lib/libarchive/archive_write_set_format_zip.c 201168 2009-12-29 06:15:32Z kientzle $");
51 
52 #ifdef HAVE_ERRNO_H
53 #include <errno.h>
54 #endif
55 #include <stdio.h>
56 #ifdef HAVE_STDLIB_H
57 #include <stdlib.h>
58 #endif
59 #ifdef HAVE_STRING_H
60 #include <string.h>
61 #endif
62 #ifdef HAVE_ZLIB_H
63 #include <zlib.h>
64 #endif
65 
66 #include "archive.h"
67 #include "archive_endian.h"
68 #include "archive_entry.h"
69 #include "archive_private.h"
70 #include "archive_write_private.h"
71 
72 #ifndef HAVE_ZLIB_H
73 #include "archive_crc32.h"
74 #endif
75 
76 #define ZIP_SIGNATURE_LOCAL_FILE_HEADER 0x04034b50
77 #define ZIP_SIGNATURE_DATA_DESCRIPTOR 0x08074b50
78 #define ZIP_SIGNATURE_FILE_HEADER 0x02014b50
79 #define ZIP_SIGNATURE_CENTRAL_DIRECTORY_END 0x06054b50
80 #define ZIP_SIGNATURE_EXTRA_TIMESTAMP 0x5455
81 #define ZIP_SIGNATURE_EXTRA_UNIX 0x7855
82 #define ZIP_VERSION_EXTRACT 0x0014 /* ZIP version 2.0 is needed. */
83 #define ZIP_VERSION_BY 0x0314 /* Made by UNIX, using ZIP version 2.0. */
84 #define ZIP_FLAGS 0x08 /* Flagging bit 3 (count from 0) for using data descriptor. */
85 
86 enum compression {
87 	COMPRESSION_STORE = 0
88 #ifdef HAVE_ZLIB_H
89 	,
90 	COMPRESSION_DEFLATE = 8
91 #endif
92 };
93 
94 static ssize_t archive_write_zip_data(struct archive_write *, const void *buff, size_t s);
95 static int archive_write_zip_finish(struct archive_write *);
96 static int archive_write_zip_destroy(struct archive_write *);
97 static int archive_write_zip_finish_entry(struct archive_write *);
98 static int archive_write_zip_header(struct archive_write *, struct archive_entry *);
99 static unsigned int dos_time(const time_t);
100 static size_t path_length(struct archive_entry *);
101 static int write_path(struct archive_entry *, struct archive_write *);
102 
103 struct zip_local_file_header {
104 	char signature[4];
105 	char version[2];
106 	char flags[2];
107 	char compression[2];
108 	char timedate[4];
109 	char crc32[4];
110 	char compressed_size[4];
111 	char uncompressed_size[4];
112 	char filename_length[2];
113 	char extra_length[2];
114 };
115 
116 struct zip_file_header {
117 	char signature[4];
118 	char version_by[2];
119 	char version_extract[2];
120 	char flags[2];
121 	char compression[2];
122 	char timedate[4];
123 	char crc32[4];
124 	char compressed_size[4];
125 	char uncompressed_size[4];
126 	char filename_length[2];
127 	char extra_length[2];
128 	char comment_length[2];
129 	char disk_number[2];
130 	char attributes_internal[2];
131 	char attributes_external[4];
132 	char offset[4];
133 };
134 
135 struct zip_data_descriptor {
136 	char signature[4]; /* Not mandatory, but recommended by specification. */
137 	char crc32[4];
138 	char compressed_size[4];
139 	char uncompressed_size[4];
140 };
141 
142 struct zip_extra_data_local {
143 	char time_id[2];
144 	char time_size[2];
145 	char time_flag[1];
146 	char mtime[4];
147 	char atime[4];
148 	char ctime[4];
149 	char unix_id[2];
150 	char unix_size[2];
151 	char unix_uid[2];
152 	char unix_gid[2];
153 };
154 
155 struct zip_extra_data_central {
156 	char time_id[2];
157 	char time_size[2];
158 	char time_flag[1];
159 	char mtime[4];
160 	char unix_id[2];
161 	char unix_size[2];
162 };
163 
164 struct zip_file_header_link {
165 	struct zip_file_header_link *next;
166 	struct archive_entry *entry;
167 	off_t offset;
168 	unsigned long crc32;
169 	off_t compressed_size;
170 	enum compression compression;
171 };
172 
173 struct zip {
174 	struct zip_data_descriptor data_descriptor;
175 	struct zip_file_header_link *central_directory;
176 	struct zip_file_header_link *central_directory_end;
177 	int64_t offset;
178 	int64_t written_bytes;
179 	int64_t remaining_data_bytes;
180 	enum compression compression;
181 
182 #ifdef HAVE_ZLIB_H
183 	z_stream stream;
184 	size_t len_buf;
185 	unsigned char *buf;
186 #endif
187 };
188 
189 struct zip_central_directory_end {
190 	char signature[4];
191 	char disk[2];
192 	char start_disk[2];
193 	char entries_disk[2];
194 	char entries[2];
195 	char size[4];
196 	char offset[4];
197 	char comment_length[2];
198 };
199 
200 static int
201 archive_write_zip_options(struct archive_write *a, const char *key,
202     const char *value)
203 {
204 	struct zip *zip = a->format_data;
205 
206 	if (strcmp(key, "compression") == 0) {
207 		if (strcmp(value, "deflate") == 0) {
208 #ifdef HAVE_ZLIB_H
209 			zip->compression = COMPRESSION_DEFLATE;
210 #else
211 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
212 			    "deflate compression not supported");
213 			return ARCHIVE_WARN;
214 #endif
215 		} else if (strcmp(value, "store") == 0)
216 			zip->compression = COMPRESSION_STORE;
217 		else
218 			return (ARCHIVE_WARN);
219 		return (ARCHIVE_OK);
220 	}
221 	return (ARCHIVE_WARN);
222 }
223 
224 int
225 archive_write_set_format_zip(struct archive *_a)
226 {
227 	struct archive_write *a = (struct archive_write *)_a;
228 	struct zip *zip;
229 
230 	/* If another format was already registered, unregister it. */
231 	if (a->format_destroy != NULL)
232 		(a->format_destroy)(a);
233 
234 	zip = (struct zip *) calloc(1, sizeof(*zip));
235 	if (zip == NULL) {
236 		archive_set_error(&a->archive, ENOMEM, "Can't allocate zip data");
237 		return (ARCHIVE_FATAL);
238 	}
239 	zip->central_directory = NULL;
240 	zip->central_directory_end = NULL;
241 	zip->offset = 0;
242 	zip->written_bytes = 0;
243 	zip->remaining_data_bytes = 0;
244 
245 #ifdef HAVE_ZLIB_H
246 	zip->compression = COMPRESSION_DEFLATE;
247 	zip->len_buf = 65536;
248 	zip->buf = malloc(zip->len_buf);
249 	if (zip->buf == NULL) {
250 		archive_set_error(&a->archive, ENOMEM, "Can't allocate compression buffer");
251 		return (ARCHIVE_FATAL);
252 	}
253 #else
254 	zip->compression = COMPRESSION_STORE;
255 #endif
256 
257 	a->format_data = zip;
258 
259 	a->pad_uncompressed = 0; /* Actually not needed for now, since no compression support yet. */
260 	a->format_name = "zip";
261 	a->format_options = archive_write_zip_options;
262 	a->format_write_header = archive_write_zip_header;
263 	a->format_write_data = archive_write_zip_data;
264 	a->format_finish_entry = archive_write_zip_finish_entry;
265 	a->format_finish = archive_write_zip_finish;
266 	a->format_destroy = archive_write_zip_destroy;
267 	a->archive.archive_format = ARCHIVE_FORMAT_ZIP;
268 	a->archive.archive_format_name = "ZIP";
269 
270 	archive_le32enc(&zip->data_descriptor.signature,
271 	    ZIP_SIGNATURE_DATA_DESCRIPTOR);
272 
273 	return (ARCHIVE_OK);
274 }
275 
276 static int
277 archive_write_zip_header(struct archive_write *a, struct archive_entry *entry)
278 {
279 	struct zip *zip;
280 	struct zip_local_file_header h;
281 	struct zip_extra_data_local e;
282 	struct zip_data_descriptor *d;
283 	struct zip_file_header_link *l;
284 	int ret;
285 	int64_t size;
286 	mode_t type;
287 
288 	/* Entries other than a regular file or a folder are skipped. */
289 	type = archive_entry_filetype(entry);
290 	if ((type != AE_IFREG) & (type != AE_IFDIR)) {
291 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Filetype not supported");
292 		return ARCHIVE_FAILED;
293 	};
294 
295 	/* Directory entries should have a size of 0. */
296 	if (type == AE_IFDIR)
297 		archive_entry_set_size(entry, 0);
298 
299 	zip = a->format_data;
300 	d = &zip->data_descriptor;
301 	size = archive_entry_size(entry);
302 	zip->remaining_data_bytes = size;
303 
304 	/* Append archive entry to the central directory data. */
305 	l = (struct zip_file_header_link *) malloc(sizeof(*l));
306 	if (l == NULL) {
307 		archive_set_error(&a->archive, ENOMEM, "Can't allocate zip header data");
308 		return (ARCHIVE_FATAL);
309 	}
310 	l->entry = archive_entry_clone(entry);
311 	/* Initialize the CRC variable and potentially the local crc32(). */
312 	l->crc32 = crc32(0, NULL, 0);
313 	l->compression = zip->compression;
314 	l->compressed_size = 0;
315 	l->next = NULL;
316 	if (zip->central_directory == NULL) {
317 		zip->central_directory = l;
318 	} else {
319 		zip->central_directory_end->next = l;
320 	}
321 	zip->central_directory_end = l;
322 
323 	/* Store the offset of this header for later use in central directory. */
324 	l->offset = zip->written_bytes;
325 
326 	memset(&h, 0, sizeof(h));
327 	archive_le32enc(&h.signature, ZIP_SIGNATURE_LOCAL_FILE_HEADER);
328 	archive_le16enc(&h.version, ZIP_VERSION_EXTRACT);
329 	archive_le16enc(&h.flags, ZIP_FLAGS);
330 	archive_le16enc(&h.compression, zip->compression);
331 	archive_le32enc(&h.timedate, dos_time(archive_entry_mtime(entry)));
332 	archive_le16enc(&h.filename_length, (uint16_t)path_length(entry));
333 
334 	switch (zip->compression) {
335 	case COMPRESSION_STORE:
336 		/* Setting compressed and uncompressed sizes even when specification says
337 		 * to set to zero when using data descriptors. Otherwise the end of the
338 		 * data for an entry is rather difficult to find. */
339 		archive_le32enc(&h.compressed_size, size);
340 		archive_le32enc(&h.uncompressed_size, size);
341 		break;
342 #ifdef HAVE_ZLIB_H
343 	case COMPRESSION_DEFLATE:
344 		archive_le32enc(&h.uncompressed_size, size);
345 
346 		zip->stream.zalloc = Z_NULL;
347 		zip->stream.zfree = Z_NULL;
348 		zip->stream.opaque = Z_NULL;
349 		zip->stream.next_out = zip->buf;
350 		zip->stream.avail_out = zip->len_buf;
351 		if (deflateInit2(&zip->stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
352 		    -15, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
353 			archive_set_error(&a->archive, ENOMEM, "Can't init deflate compressor");
354 			return (ARCHIVE_FATAL);
355 		}
356 		break;
357 #endif
358 	}
359 
360 	/* Formatting extra data. */
361 	archive_le16enc(&h.extra_length, sizeof(e));
362 	archive_le16enc(&e.time_id, ZIP_SIGNATURE_EXTRA_TIMESTAMP);
363 	archive_le16enc(&e.time_size, sizeof(e.time_flag) +
364 	    sizeof(e.mtime) + sizeof(e.atime) + sizeof(e.ctime));
365 	e.time_flag[0] = 0x07;
366 	archive_le32enc(&e.mtime, archive_entry_mtime(entry));
367 	archive_le32enc(&e.atime, archive_entry_atime(entry));
368 	archive_le32enc(&e.ctime, archive_entry_ctime(entry));
369 
370 	archive_le16enc(&e.unix_id, ZIP_SIGNATURE_EXTRA_UNIX);
371 	archive_le16enc(&e.unix_size, sizeof(e.unix_uid) + sizeof(e.unix_gid));
372 	archive_le16enc(&e.unix_uid, archive_entry_uid(entry));
373 	archive_le16enc(&e.unix_gid, archive_entry_gid(entry));
374 
375 	archive_le32enc(&d->uncompressed_size, size);
376 
377 	ret = (a->compressor.write)(a, &h, sizeof(h));
378 	if (ret != ARCHIVE_OK)
379 		return (ARCHIVE_FATAL);
380 	zip->written_bytes += sizeof(h);
381 
382 	ret = write_path(entry, a);
383 	if (ret <= ARCHIVE_OK)
384 		return (ARCHIVE_FATAL);
385 	zip->written_bytes += ret;
386 
387 	ret = (a->compressor.write)(a, &e, sizeof(e));
388 	if (ret != ARCHIVE_OK)
389 		return (ARCHIVE_FATAL);
390 	zip->written_bytes += sizeof(e);
391 
392 	return (ARCHIVE_OK);
393 }
394 
395 static ssize_t
396 archive_write_zip_data(struct archive_write *a, const void *buff, size_t s)
397 {
398 	int ret;
399 	struct zip *zip = a->format_data;
400 	struct zip_file_header_link *l = zip->central_directory_end;
401 
402 	if ((int64_t)s > zip->remaining_data_bytes)
403 		s = (size_t)zip->remaining_data_bytes;
404 
405 	if (s == 0) return 0;
406 
407 	switch (zip->compression) {
408 	case COMPRESSION_STORE:
409 		ret = (a->compressor.write)(a, buff, s);
410 		if (ret != ARCHIVE_OK) return (ret);
411 		zip->written_bytes += s;
412 		zip->remaining_data_bytes -= s;
413 		l->compressed_size += s;
414 		l->crc32 = crc32(l->crc32, buff, s);
415 		return (s);
416 #if HAVE_ZLIB_H
417 	case COMPRESSION_DEFLATE:
418 		zip->stream.next_in = (unsigned char*)(uintptr_t)buff;
419 		zip->stream.avail_in = s;
420 		do {
421 			ret = deflate(&zip->stream, Z_NO_FLUSH);
422 			if (ret == Z_STREAM_ERROR)
423 				return (ARCHIVE_FATAL);
424 			if (zip->stream.avail_out == 0) {
425 				ret = (a->compressor.write)(a, zip->buf, zip->len_buf);
426 				if (ret != ARCHIVE_OK)
427 					return (ret);
428 				l->compressed_size += zip->len_buf;
429 				zip->written_bytes += zip->len_buf;
430 				zip->stream.next_out = zip->buf;
431 				zip->stream.avail_out = zip->len_buf;
432 			}
433 		} while (zip->stream.avail_in != 0);
434 		zip->remaining_data_bytes -= s;
435 		/* If we have it, use zlib's fast crc32() */
436 		l->crc32 = crc32(l->crc32, buff, s);
437 		return (s);
438 #endif
439 
440 	default:
441 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
442 		    "Invalid ZIP compression type");
443 		return ARCHIVE_FATAL;
444 	}
445 }
446 
447 static int
448 archive_write_zip_finish_entry(struct archive_write *a)
449 {
450 	/* Write the data descripter after file data has been written. */
451 	int ret;
452 	struct zip *zip = a->format_data;
453 	struct zip_data_descriptor *d = &zip->data_descriptor;
454 	struct zip_file_header_link *l = zip->central_directory_end;
455 #if HAVE_ZLIB_H
456 	size_t reminder;
457 #endif
458 
459 	switch(zip->compression) {
460 	case COMPRESSION_STORE:
461 		break;
462 #if HAVE_ZLIB_H
463 	case COMPRESSION_DEFLATE:
464 		for (;;) {
465 			ret = deflate(&zip->stream, Z_FINISH);
466 			if (ret == Z_STREAM_ERROR)
467 				return (ARCHIVE_FATAL);
468 			reminder = zip->len_buf - zip->stream.avail_out;
469 			ret = (a->compressor.write)(a, zip->buf, reminder);
470 			if (ret != ARCHIVE_OK)
471 				return (ret);
472 			l->compressed_size += reminder;
473 			zip->written_bytes += reminder;
474 			zip->stream.next_out = zip->buf;
475 			if (zip->stream.avail_out != 0)
476 				break;
477 			zip->stream.avail_out = zip->len_buf;
478 		}
479 		deflateEnd(&zip->stream);
480 		break;
481 #endif
482 	}
483 
484 	archive_le32enc(&d->crc32, l->crc32);
485 	archive_le32enc(&d->compressed_size, l->compressed_size);
486 	ret = (a->compressor.write)(a, d, sizeof(*d));
487 	if (ret != ARCHIVE_OK)
488 		return (ARCHIVE_FATAL);
489 	zip->written_bytes += sizeof(*d);
490 	return (ARCHIVE_OK);
491 }
492 
493 static int
494 archive_write_zip_finish(struct archive_write *a)
495 {
496 	struct zip *zip;
497 	struct zip_file_header_link *l;
498 	struct zip_file_header h;
499 	struct zip_central_directory_end end;
500 	struct zip_extra_data_central e;
501 	off_t offset_start, offset_end;
502 	int entries;
503 	int ret;
504 
505 	zip = a->format_data;
506 	l = zip->central_directory;
507 
508 	/*
509 	 * Formatting central directory file header fields that are fixed for all entries.
510 	 * Fields not used (and therefor 0) are:
511 	 *
512 	 *   - comment_length
513 	 *   - disk_number
514 	 *   - attributes_internal
515 	 */
516 	memset(&h, 0, sizeof(h));
517 	archive_le32enc(&h.signature, ZIP_SIGNATURE_FILE_HEADER);
518 	archive_le16enc(&h.version_by, ZIP_VERSION_BY);
519 	archive_le16enc(&h.version_extract, ZIP_VERSION_EXTRACT);
520 	archive_le16enc(&h.flags, ZIP_FLAGS);
521 
522 	entries = 0;
523 	offset_start = zip->written_bytes;
524 
525 	/* Formatting individual header fields per entry and
526 	 * writing each entry. */
527 	while (l != NULL) {
528 		archive_le16enc(&h.compression, l->compression);
529 		archive_le32enc(&h.timedate, dos_time(archive_entry_mtime(l->entry)));
530 		archive_le32enc(&h.crc32, l->crc32);
531 		archive_le32enc(&h.compressed_size, l->compressed_size);
532 		archive_le32enc(&h.uncompressed_size, archive_entry_size(l->entry));
533 		archive_le16enc(&h.filename_length, (uint16_t)path_length(l->entry));
534 		archive_le16enc(&h.extra_length, sizeof(e));
535 		archive_le16enc(&h.attributes_external[2], archive_entry_mode(l->entry));
536 		archive_le32enc(&h.offset, l->offset);
537 
538 		/* Formatting extra data. */
539 		archive_le16enc(&e.time_id, ZIP_SIGNATURE_EXTRA_TIMESTAMP);
540 		archive_le16enc(&e.time_size, sizeof(e.mtime) + sizeof(e.time_flag));
541 		e.time_flag[0] = 0x07;
542 		archive_le32enc(&e.mtime, archive_entry_mtime(l->entry));
543 		archive_le16enc(&e.unix_id, ZIP_SIGNATURE_EXTRA_UNIX);
544 		archive_le16enc(&e.unix_size, 0x0000);
545 
546 		ret = (a->compressor.write)(a, &h, sizeof(h));
547 		if (ret != ARCHIVE_OK)
548 			return (ARCHIVE_FATAL);
549 		zip->written_bytes += sizeof(h);
550 
551 		ret = write_path(l->entry, a);
552 		if (ret <= ARCHIVE_OK)
553 			return (ARCHIVE_FATAL);
554 		zip->written_bytes += ret;
555 
556 		ret = (a->compressor.write)(a, &e, sizeof(e));
557 		if (ret != ARCHIVE_OK)
558 			return (ARCHIVE_FATAL);
559 		zip->written_bytes += sizeof(e);
560 
561 		l = l->next;
562 		entries++;
563 	}
564 	offset_end = zip->written_bytes;
565 
566 	/* Formatting end of central directory. */
567 	memset(&end, 0, sizeof(end));
568 	archive_le32enc(&end.signature, ZIP_SIGNATURE_CENTRAL_DIRECTORY_END);
569 	archive_le16enc(&end.entries_disk, entries);
570 	archive_le16enc(&end.entries, entries);
571 	archive_le32enc(&end.size, offset_end - offset_start);
572 	archive_le32enc(&end.offset, offset_start);
573 
574 	/* Writing end of central directory. */
575 	ret = (a->compressor.write)(a, &end, sizeof(end));
576 	if (ret != ARCHIVE_OK)
577 		return (ARCHIVE_FATAL);
578 	zip->written_bytes += sizeof(end);
579 	return (ARCHIVE_OK);
580 }
581 
582 static int
583 archive_write_zip_destroy(struct archive_write *a)
584 {
585 	struct zip *zip;
586 	struct zip_file_header_link *l;
587 
588 	zip = a->format_data;
589 	while (zip->central_directory != NULL) {
590 	   l = zip->central_directory;
591 	   zip->central_directory = l->next;
592 	   archive_entry_free(l->entry);
593 	   free(l);
594 	}
595 #ifdef HAVE_ZLIB_H
596 	free(zip->buf);
597 #endif
598 	free(zip);
599 	a->format_data = NULL;
600 	return (ARCHIVE_OK);
601 }
602 
603 /* Convert into MSDOS-style date/time. */
604 static unsigned int
605 dos_time(const time_t unix_time)
606 {
607 	struct tm *t;
608 	unsigned int dt;
609 
610 	/* This will not preserve time when creating/extracting the archive
611 	 * on two systems with different time zones. */
612 	t = localtime(&unix_time);
613 
614 	dt = 0;
615 	dt += ((t->tm_year - 80) & 0x7f) << 9;
616 	dt += ((t->tm_mon + 1) & 0x0f) << 5;
617 	dt += (t->tm_mday & 0x1f);
618 	dt <<= 16;
619 	dt += (t->tm_hour & 0x1f) << 11;
620 	dt += (t->tm_min & 0x3f) << 5;
621 	dt += (t->tm_sec & 0x3e) >> 1; /* Only counting every 2 seconds. */
622 	return dt;
623 }
624 
625 static size_t
626 path_length(struct archive_entry *entry)
627 {
628 	mode_t type;
629 	const char *path;
630 
631 	type = archive_entry_filetype(entry);
632 	path = archive_entry_pathname(entry);
633 
634 	if ((type == AE_IFDIR) & (path[strlen(path) - 1] != '/')) {
635 		return strlen(path) + 1;
636 	} else {
637 		return strlen(path);
638 	}
639 }
640 
641 static int
642 write_path(struct archive_entry *entry, struct archive_write *archive)
643 {
644 	int ret;
645 	const char *path;
646 	mode_t type;
647 	size_t written_bytes;
648 
649 	path = archive_entry_pathname(entry);
650 	type = archive_entry_filetype(entry);
651 	written_bytes = 0;
652 
653 	ret = (archive->compressor.write)(archive, path, strlen(path));
654 	if (ret != ARCHIVE_OK)
655 		return (ARCHIVE_FATAL);
656 	written_bytes += strlen(path);
657 
658 	/* Folders are recognized by a traling slash. */
659 	if ((type == AE_IFDIR) & (path[strlen(path) - 1] != '/')) {
660 		ret = (archive->compressor.write)(archive, "/", 1);
661 		if (ret != ARCHIVE_OK)
662 			return (ARCHIVE_FATAL);
663 		written_bytes += 1;
664 	}
665 
666 	return ((int)written_bytes);
667 }
668