summaryrefslogtreecommitdiff
path: root/archivers/libarchive/files/libarchive/archive_write_set_format_v7tar.c
blob: 62b15229444c46272d8efd84cbc5a71e4fbcbb00 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
/*-
 * Copyright (c) 2003-2007 Tim Kientzle
 * Copyright (c) 2011-2012 Michihiro NAKAJIMA
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "archive_platform.h"
__FBSDID("$FreeBSD$");


#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif

#include "archive.h"
#include "archive_entry.h"
#include "archive_entry_locale.h"
#include "archive_private.h"
#include "archive_write_private.h"

struct v7tar {
	uint64_t	entry_bytes_remaining;
	uint64_t	entry_padding;

	struct archive_string_conv *opt_sconv;
	struct archive_string_conv *sconv_default;
	int	init_default_conversion;
};

/*
 * Define structure of POSIX 'v7tar' tar header.
 */
#define	V7TAR_name_offset 0
#define	V7TAR_name_size 100
#define	V7TAR_mode_offset 100
#define	V7TAR_mode_size 6
#define	V7TAR_mode_max_size 8
#define	V7TAR_uid_offset 108
#define	V7TAR_uid_size 6
#define	V7TAR_uid_max_size 8
#define	V7TAR_gid_offset 116
#define	V7TAR_gid_size 6
#define	V7TAR_gid_max_size 8
#define	V7TAR_size_offset 124
#define	V7TAR_size_size 11
#define	V7TAR_size_max_size 12
#define	V7TAR_mtime_offset 136
#define	V7TAR_mtime_size 11
#define	V7TAR_mtime_max_size 12
#define	V7TAR_checksum_offset 148
#define	V7TAR_checksum_size 8
#define	V7TAR_typeflag_offset 156
#define	V7TAR_typeflag_size 1
#define	V7TAR_linkname_offset 157
#define	V7TAR_linkname_size 100
#define	V7TAR_padding_offset 257
#define	V7TAR_padding_size 255

/*
 * A filled-in copy of the header for initialization.
 */
static const char template_header[] = {
	/* name: 100 bytes */
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,
	/* Mode, space-null termination: 8 bytes */
	'0','0','0','0','0','0', ' ','\0',
	/* uid, space-null termination: 8 bytes */
	'0','0','0','0','0','0', ' ','\0',
	/* gid, space-null termination: 8 bytes */
	'0','0','0','0','0','0', ' ','\0',
	/* size, space termination: 12 bytes */
	'0','0','0','0','0','0','0','0','0','0','0', ' ',
	/* mtime, space termination: 12 bytes */
	'0','0','0','0','0','0','0','0','0','0','0', ' ',
	/* Initial checksum value: 8 spaces */
	' ',' ',' ',' ',' ',' ',' ',' ',
	/* Typeflag: 1 byte */
	0,
	/* Linkname: 100 bytes */
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,
	/* Padding: 255 bytes */
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0
};

static ssize_t	archive_write_v7tar_data(struct archive_write *a, const void *buff,
		    size_t s);
static int	archive_write_v7tar_free(struct archive_write *);
static int	archive_write_v7tar_close(struct archive_write *);
static int	archive_write_v7tar_finish_entry(struct archive_write *);
static int	archive_write_v7tar_header(struct archive_write *,
		    struct archive_entry *entry);
static int	archive_write_v7tar_options(struct archive_write *,
		    const char *, const char *);
static int	format_256(int64_t, char *, int);
static int	format_number(int64_t, char *, int size, int max, int strict);
static int	format_octal(int64_t, char *, int);
static int	format_header_v7tar(struct archive_write *, char h[512],
		    struct archive_entry *, int, struct archive_string_conv *);

/*
 * Set output format to 'v7tar' format.
 */
int
archive_write_set_format_v7tar(struct archive *_a)
{
	struct archive_write *a = (struct archive_write *)_a;
	struct v7tar *v7tar;

	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
	    ARCHIVE_STATE_NEW, "archive_write_set_format_v7tar");

	/* If someone else was already registered, unregister them. */
	if (a->format_free != NULL)
		(a->format_free)(a);

	/* Basic internal sanity test. */
	if (sizeof(template_header) != 512) {
		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
		    "Internal: template_header wrong size: %zu should be 512",
		    sizeof(template_header));
		return (ARCHIVE_FATAL);
	}

	v7tar = (struct v7tar *)calloc(1, sizeof(*v7tar));
	if (v7tar == NULL) {
		archive_set_error(&a->archive, ENOMEM,
		    "Can't allocate v7tar data");
		return (ARCHIVE_FATAL);
	}
	a->format_data = v7tar;
	a->format_name = "tar (non-POSIX)";
	a->format_options = archive_write_v7tar_options;
	a->format_write_header = archive_write_v7tar_header;
	a->format_write_data = archive_write_v7tar_data;
	a->format_close = archive_write_v7tar_close;
	a->format_free = archive_write_v7tar_free;
	a->format_finish_entry = archive_write_v7tar_finish_entry;
	a->archive.archive_format = ARCHIVE_FORMAT_TAR;
	a->archive.archive_format_name = "tar (non-POSIX)";
	return (ARCHIVE_OK);
}

static int
archive_write_v7tar_options(struct archive_write *a, const char *key,
    const char *val)
{
	struct v7tar *v7tar = (struct v7tar *)a->format_data;
	int ret = ARCHIVE_FAILED;

	if (strcmp(key, "hdrcharset")  == 0) {
		if (val == NULL || val[0] == 0)
			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
			    "%s: hdrcharset option needs a character-set name",
			    a->format_name);
		else {
			v7tar->opt_sconv = archive_string_conversion_to_charset(
			    &a->archive, val, 0);
			if (v7tar->opt_sconv != NULL)
				ret = ARCHIVE_OK;
			else
				ret = ARCHIVE_FATAL;
		}
		return (ret);
	}

	/* Note: The "warn" return is just to inform the options
	 * supervisor that we didn't handle it.  It will generate
	 * a suitable error if no one used this option. */
	return (ARCHIVE_WARN);
}

static int
archive_write_v7tar_header(struct archive_write *a, struct archive_entry *entry)
{
	char buff[512];
	int ret, ret2;
	struct v7tar *v7tar;
	struct archive_entry *entry_main;
	struct archive_string_conv *sconv;

	v7tar = (struct v7tar *)a->format_data;

	/* Setup default string conversion. */
	if (v7tar->opt_sconv == NULL) {
		if (!v7tar->init_default_conversion) {
			v7tar->sconv_default =
			    archive_string_default_conversion_for_write(
				&(a->archive));
			v7tar->init_default_conversion = 1;
		}
		sconv = v7tar->sconv_default;
	} else
		sconv = v7tar->opt_sconv;

	/* Sanity check. */
	if (archive_entry_pathname(entry) == NULL) {
		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
		    "Can't record entry in tar file without pathname");
		return (ARCHIVE_FAILED);
	}

	/* Only regular files (not hardlinks) have data. */
	if (archive_entry_hardlink(entry) != NULL ||
	    archive_entry_symlink(entry) != NULL ||
	    !(archive_entry_filetype(entry) == AE_IFREG))
		archive_entry_set_size(entry, 0);

	if (AE_IFDIR == archive_entry_filetype(entry)) {
		const char *p;
		size_t path_length;
		/*
		 * Ensure a trailing '/'.  Modify the entry so
		 * the client sees the change.
		 */
#if defined(_WIN32) && !defined(__CYGWIN__)
		const wchar_t *wp;

		wp = archive_entry_pathname_w(entry);
		if (wp != NULL && wp[wcslen(wp) -1] != L'/') {
			struct archive_wstring ws;

			archive_string_init(&ws);
			path_length = wcslen(wp);
			if (archive_wstring_ensure(&ws,
			    path_length + 2) == NULL) {
				archive_set_error(&a->archive, ENOMEM,
				    "Can't allocate v7tar data");
				archive_wstring_free(&ws);
				return(ARCHIVE_FATAL);
			}
			/* Should we keep '\' ? */
			if (wp[path_length -1] == L'\\')
				path_length--;
			archive_wstrncpy(&ws, wp, path_length);
			archive_wstrappend_wchar(&ws, L'/');
			archive_entry_copy_pathname_w(entry, ws.s);
			archive_wstring_free(&ws);
			p = NULL;
		} else
#endif
			p = archive_entry_pathname(entry);
		/*
		 * On Windows, this is a backup operation just in
		 * case getting WCS failed. On POSIX, this is a
		 * normal operation.
		 */
		if (p != NULL && p[strlen(p) - 1] != '/') {
			struct archive_string as;

			archive_string_init(&as);
			path_length = strlen(p);
			if (archive_string_ensure(&as,
			    path_length + 2) == NULL) {
				archive_set_error(&a->archive, ENOMEM,
				    "Can't allocate v7tar data");
				archive_string_free(&as);
				return(ARCHIVE_FATAL);
			}
#if defined(_WIN32) && !defined(__CYGWIN__)
			/* NOTE: This might break the pathname
			 * if the current code page is CP932 and
			 * the pathname includes a character '\'
			 * as a part of its multibyte pathname. */
			if (p[strlen(p) -1] == '\\')
				path_length--;
			else
#endif
			archive_strncpy(&as, p, path_length);
			archive_strappend_char(&as, '/');
			archive_entry_copy_pathname(entry, as.s);
			archive_string_free(&as);
		}
	}

#if defined(_WIN32) && !defined(__CYGWIN__)
	/* Make sure the path separators in pathname, hardlink and symlink
	 * are all slash '/', not the Windows path separator '\'. */
	entry_main = __la_win_entry_in_posix_pathseparator(entry);
	if (entry_main == NULL) {
		archive_set_error(&a->archive, ENOMEM,
		    "Can't allocate v7tar data");
		return(ARCHIVE_FATAL);
	}
	if (entry != entry_main)
		entry = entry_main;
	else
		entry_main = NULL;
#else
	entry_main = NULL;
#endif
	ret = format_header_v7tar(a, buff, entry, 1, sconv);
	if (ret < ARCHIVE_WARN) {
		if (entry_main)
			archive_entry_free(entry_main);
		return (ret);
	}
	ret2 = __archive_write_output(a, buff, 512);
	if (ret2 < ARCHIVE_WARN) {
		if (entry_main)
			archive_entry_free(entry_main);
		return (ret2);
	}
	if (ret2 < ret)
		ret = ret2;

	v7tar->entry_bytes_remaining = archive_entry_size(entry);
	v7tar->entry_padding = 0x1ff & (-(int64_t)v7tar->entry_bytes_remaining);
	if (entry_main)
		archive_entry_free(entry_main);
	return (ret);
}

/*
 * Format a basic 512-byte "v7tar" header.
 *
 * Returns -1 if format failed (due to field overflow).
 * Note that this always formats as much of the header as possible.
 * If "strict" is set to zero, it will extend numeric fields as
 * necessary (overwriting terminators or using base-256 extensions).
 *
 */
static int
format_header_v7tar(struct archive_write *a, char h[512],
    struct archive_entry *entry, int strict,
    struct archive_string_conv *sconv)
{
	unsigned int checksum;
	int i, r, ret;
	size_t copy_length;
	const char *p, *pp;
	int mytartype;

	ret = 0;
	mytartype = -1;
	/*
	 * The "template header" already includes the "v7tar"
	 * signature, various end-of-field markers and other required
	 * elements.
	 */
	memcpy(h, &template_header, 512);

	/*
	 * Because the block is already null-filled, and strings
	 * are allowed to exactly fill their destination (without null),
	 * I use memcpy(dest, src, strlen()) here a lot to copy strings.
	 */
	r = archive_entry_pathname_l(entry, &pp, &copy_length, sconv);
	if (r != 0) {
		if (errno == ENOMEM) {
			archive_set_error(&a->archive, ENOMEM,
			    "Can't allocate memory for Pathname");
			return (ARCHIVE_FATAL);
		}
		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
		    "Can't translate pathname '%s' to %s",
		    pp, archive_string_conversion_charset_name(sconv));
		ret = ARCHIVE_WARN;
	}
	if (strict && copy_length < V7TAR_name_size)
		memcpy(h + V7TAR_name_offset, pp, copy_length);
	else if (!strict && copy_length <= V7TAR_name_size)
		memcpy(h + V7TAR_name_offset, pp, copy_length);
	else {
		/* Prefix is too long. */
		archive_set_error(&a->archive, ENAMETOOLONG,
		    "Pathname too long");
		ret = ARCHIVE_FAILED;
	}

	r = archive_entry_hardlink_l(entry, &p, &copy_length, sconv);
	if (r != 0) {
		if (errno == ENOMEM) {
			archive_set_error(&a->archive, ENOMEM,
			    "Can't allocate memory for Linkname");
			return (ARCHIVE_FATAL);
		}
		archive_set_error(&a->archive,
		    ARCHIVE_ERRNO_FILE_FORMAT,
		    "Can't translate linkname '%s' to %s",
		    p, archive_string_conversion_charset_name(sconv));
		ret = ARCHIVE_WARN;
	}
	if (copy_length > 0)
		mytartype = '1';
	else {
		r = archive_entry_symlink_l(entry, &p, &copy_length, sconv);
		if (r != 0) {
			if (errno == ENOMEM) {
				archive_set_error(&a->archive, ENOMEM,
				    "Can't allocate memory for Linkname");
				return (ARCHIVE_FATAL);
			}
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "Can't translate linkname '%s' to %s",
			    p, archive_string_conversion_charset_name(sconv));
			ret = ARCHIVE_WARN;
		}
	}
	if (copy_length > 0) {
		if (copy_length >= V7TAR_linkname_size) {
			archive_set_error(&a->archive, ENAMETOOLONG,
			    "Link contents too long");
			ret = ARCHIVE_FAILED;
			copy_length = V7TAR_linkname_size;
		}
		memcpy(h + V7TAR_linkname_offset, p, copy_length);
	}

	if (format_number(archive_entry_mode(entry) & 07777,
	    h + V7TAR_mode_offset, V7TAR_mode_size,
	    V7TAR_mode_max_size, strict)) {
		archive_set_error(&a->archive, ERANGE,
		    "Numeric mode too large");
		ret = ARCHIVE_FAILED;
	}

	if (format_number(archive_entry_uid(entry),
	    h + V7TAR_uid_offset, V7TAR_uid_size, V7TAR_uid_max_size, strict)) {
		archive_set_error(&a->archive, ERANGE,
		    "Numeric user ID too large");
		ret = ARCHIVE_FAILED;
	}

	if (format_number(archive_entry_gid(entry),
	    h + V7TAR_gid_offset, V7TAR_gid_size, V7TAR_gid_max_size, strict)) {
		archive_set_error(&a->archive, ERANGE,
		    "Numeric group ID too large");
		ret = ARCHIVE_FAILED;
	}

	if (format_number(archive_entry_size(entry),
	    h + V7TAR_size_offset, V7TAR_size_size,
	    V7TAR_size_max_size, strict)) {
		archive_set_error(&a->archive, ERANGE,
		    "File size out of range");
		ret = ARCHIVE_FAILED;
	}

	if (format_number(archive_entry_mtime(entry),
	    h + V7TAR_mtime_offset, V7TAR_mtime_size,
	    V7TAR_mtime_max_size, strict)) {
		archive_set_error(&a->archive, ERANGE,
		    "File modification time too large");
		ret = ARCHIVE_FAILED;
	}

	if (mytartype >= 0) {
		h[V7TAR_typeflag_offset] = mytartype;
	} else {
		switch (archive_entry_filetype(entry)) {
		case AE_IFREG: case AE_IFDIR:
			break;
		case AE_IFLNK:
			h[V7TAR_typeflag_offset] = '2';
			break;
		case AE_IFCHR:
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "tar format cannot archive character device");
			return (ARCHIVE_FAILED);
		case AE_IFBLK:
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "tar format cannot archive block device");
			return (ARCHIVE_FAILED);
		case AE_IFIFO:
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "tar format cannot archive fifo");
			return (ARCHIVE_FAILED);
		case AE_IFSOCK:
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "tar format cannot archive socket");
			return (ARCHIVE_FAILED);
		default:
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "tar format cannot archive this (mode=0%lo)",
			    (unsigned long)archive_entry_mode(entry));
			ret = ARCHIVE_FAILED;
		}
	}

	checksum = 0;
	for (i = 0; i < 512; i++)
		checksum += 255 & (unsigned int)h[i];
	format_octal(checksum, h + V7TAR_checksum_offset, 6);
	/* Can't be pre-set in the template. */
	h[V7TAR_checksum_offset + 6] = '\0';
	return (ret);
}

/*
 * Format a number into a field, with some intelligence.
 */
static int
format_number(int64_t v, char *p, int s, int maxsize, int strict)
{
	int64_t limit;

	limit = ((int64_t)1 << (s*3));

	/* "Strict" only permits octal values with proper termination. */
	if (strict)
		return (format_octal(v, p, s));

	/*
	 * In non-strict mode, we allow the number to overwrite one or
	 * more bytes of the field termination.  Even old tar
	 * implementations should be able to handle this with no
	 * problem.
	 */
	if (v >= 0) {
		while (s <= maxsize) {
			if (v < limit)
				return (format_octal(v, p, s));
			s++;
			limit <<= 3;
		}
	}

	/* Base-256 can handle any number, positive or negative. */
	return (format_256(v, p, maxsize));
}

/*
 * Format a number into the specified field using base-256.
 */
static int
format_256(int64_t v, char *p, int s)
{
	p += s;
	while (s-- > 0) {
		*--p = (char)(v & 0xff);
		v >>= 8;
	}
	*p |= 0x80; /* Set the base-256 marker bit. */
	return (0);
}

/*
 * Format a number into the specified field.
 */
static int
format_octal(int64_t v, char *p, int s)
{
	int len;

	len = s;

	/* Octal values can't be negative, so use 0. */
	if (v < 0) {
		while (len-- > 0)
			*p++ = '0';
		return (-1);
	}

	p += s;		/* Start at the end and work backwards. */
	while (s-- > 0) {
		*--p = (char)('0' + (v & 7));
		v >>= 3;
	}

	if (v == 0)
		return (0);

	/* If it overflowed, fill field with max value. */
	while (len-- > 0)
		*p++ = '7';

	return (-1);
}

static int
archive_write_v7tar_close(struct archive_write *a)
{
	return (__archive_write_nulls(a, 512*2));
}

static int
archive_write_v7tar_free(struct archive_write *a)
{
	struct v7tar *v7tar;

	v7tar = (struct v7tar *)a->format_data;
	free(v7tar);
	a->format_data = NULL;
	return (ARCHIVE_OK);
}

static int
archive_write_v7tar_finish_entry(struct archive_write *a)
{
	struct v7tar *v7tar;
	int ret;

	v7tar = (struct v7tar *)a->format_data;
	ret = __archive_write_nulls(a,
	    (size_t)(v7tar->entry_bytes_remaining + v7tar->entry_padding));
	v7tar->entry_bytes_remaining = v7tar->entry_padding = 0;
	return (ret);
}

static ssize_t
archive_write_v7tar_data(struct archive_write *a, const void *buff, size_t s)
{
	struct v7tar *v7tar;
	int ret;

	v7tar = (struct v7tar *)a->format_data;
	if (s > v7tar->entry_bytes_remaining)
		s = (size_t)v7tar->entry_bytes_remaining;
	ret = __archive_write_output(a, buff, s);
	v7tar->entry_bytes_remaining -= s;
	if (ret != ARCHIVE_OK)
		return (ret);
	return (s);
}