xref: /freebsd/contrib/libarchive/libarchive/archive_write_set_format_ustar.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * Copyright (c) 2011-2012 Michihiro NAKAJIMA
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 #include "archive_platform.h"
28 __FBSDID("$FreeBSD$");
29 
30 
31 #ifdef HAVE_ERRNO_H
32 #include <errno.h>
33 #endif
34 #include <stdio.h>
35 #ifdef HAVE_STDLIB_H
36 #include <stdlib.h>
37 #endif
38 #ifdef HAVE_STRING_H
39 #include <string.h>
40 #endif
41 
42 #include "archive.h"
43 #include "archive_entry.h"
44 #include "archive_entry_locale.h"
45 #include "archive_private.h"
46 #include "archive_write_private.h"
47 
48 struct ustar {
49 	uint64_t	entry_bytes_remaining;
50 	uint64_t	entry_padding;
51 
52 	struct archive_string_conv *opt_sconv;
53 	struct archive_string_conv *sconv_default;
54 	int	init_default_conversion;
55 };
56 
57 /*
58  * Define structure of POSIX 'ustar' tar header.
59  */
60 #define	USTAR_name_offset 0
61 #define	USTAR_name_size 100
62 #define	USTAR_mode_offset 100
63 #define	USTAR_mode_size 6
64 #define	USTAR_mode_max_size 8
65 #define	USTAR_uid_offset 108
66 #define	USTAR_uid_size 6
67 #define	USTAR_uid_max_size 8
68 #define	USTAR_gid_offset 116
69 #define	USTAR_gid_size 6
70 #define	USTAR_gid_max_size 8
71 #define	USTAR_size_offset 124
72 #define	USTAR_size_size 11
73 #define	USTAR_size_max_size 12
74 #define	USTAR_mtime_offset 136
75 #define	USTAR_mtime_size 11
76 #define	USTAR_mtime_max_size 11
77 #define	USTAR_checksum_offset 148
78 #define	USTAR_checksum_size 8
79 #define	USTAR_typeflag_offset 156
80 #define	USTAR_typeflag_size 1
81 #define	USTAR_linkname_offset 157
82 #define	USTAR_linkname_size 100
83 #define	USTAR_magic_offset 257
84 #define	USTAR_magic_size 6
85 #define	USTAR_version_offset 263
86 #define	USTAR_version_size 2
87 #define	USTAR_uname_offset 265
88 #define	USTAR_uname_size 32
89 #define	USTAR_gname_offset 297
90 #define	USTAR_gname_size 32
91 #define	USTAR_rdevmajor_offset 329
92 #define	USTAR_rdevmajor_size 6
93 #define	USTAR_rdevmajor_max_size 8
94 #define	USTAR_rdevminor_offset 337
95 #define	USTAR_rdevminor_size 6
96 #define	USTAR_rdevminor_max_size 8
97 #define	USTAR_prefix_offset 345
98 #define	USTAR_prefix_size 155
99 #define	USTAR_padding_offset 500
100 #define	USTAR_padding_size 12
101 
102 /*
103  * A filled-in copy of the header for initialization.
104  */
105 static const char template_header[] = {
106 	/* name: 100 bytes */
107 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
108 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
109 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
110 	0,0,0,0,
111 	/* Mode, space-null termination: 8 bytes */
112 	'0','0','0','0','0','0', ' ','\0',
113 	/* uid, space-null termination: 8 bytes */
114 	'0','0','0','0','0','0', ' ','\0',
115 	/* gid, space-null termination: 8 bytes */
116 	'0','0','0','0','0','0', ' ','\0',
117 	/* size, space termation: 12 bytes */
118 	'0','0','0','0','0','0','0','0','0','0','0', ' ',
119 	/* mtime, space termation: 12 bytes */
120 	'0','0','0','0','0','0','0','0','0','0','0', ' ',
121 	/* Initial checksum value: 8 spaces */
122 	' ',' ',' ',' ',' ',' ',' ',' ',
123 	/* Typeflag: 1 byte */
124 	'0',			/* '0' = regular file */
125 	/* Linkname: 100 bytes */
126 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
127 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
128 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
129 	0,0,0,0,
130 	/* Magic: 6 bytes, Version: 2 bytes */
131 	'u','s','t','a','r','\0', '0','0',
132 	/* Uname: 32 bytes */
133 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
134 	/* Gname: 32 bytes */
135 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
136 	/* rdevmajor + space/null padding: 8 bytes */
137 	'0','0','0','0','0','0', ' ','\0',
138 	/* rdevminor + space/null padding: 8 bytes */
139 	'0','0','0','0','0','0', ' ','\0',
140 	/* Prefix: 155 bytes */
141 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
142 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
143 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
144 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
145 	0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,
146 	/* Padding: 12 bytes */
147 	0,0,0,0,0,0,0,0, 0,0,0,0
148 };
149 
150 static ssize_t	archive_write_ustar_data(struct archive_write *a, const void *buff,
151 		    size_t s);
152 static int	archive_write_ustar_free(struct archive_write *);
153 static int	archive_write_ustar_close(struct archive_write *);
154 static int	archive_write_ustar_finish_entry(struct archive_write *);
155 static int	archive_write_ustar_header(struct archive_write *,
156 		    struct archive_entry *entry);
157 static int	archive_write_ustar_options(struct archive_write *,
158 		    const char *, const char *);
159 static int	format_256(int64_t, char *, int);
160 static int	format_number(int64_t, char *, int size, int max, int strict);
161 static int	format_octal(int64_t, char *, int);
162 
163 /*
164  * Set output format to 'ustar' format.
165  */
166 int
167 archive_write_set_format_ustar(struct archive *_a)
168 {
169 	struct archive_write *a = (struct archive_write *)_a;
170 	struct ustar *ustar;
171 
172 	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
173 	    ARCHIVE_STATE_NEW, "archive_write_set_format_ustar");
174 
175 	/* If someone else was already registered, unregister them. */
176 	if (a->format_free != NULL)
177 		(a->format_free)(a);
178 
179 	/* Basic internal sanity test. */
180 	if (sizeof(template_header) != 512) {
181 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
182 		    "Internal: template_header wrong size: %zu should be 512",
183 		    sizeof(template_header));
184 		return (ARCHIVE_FATAL);
185 	}
186 
187 	ustar = (struct ustar *)malloc(sizeof(*ustar));
188 	if (ustar == NULL) {
189 		archive_set_error(&a->archive, ENOMEM,
190 		    "Can't allocate ustar data");
191 		return (ARCHIVE_FATAL);
192 	}
193 	memset(ustar, 0, sizeof(*ustar));
194 	a->format_data = ustar;
195 	a->format_name = "ustar";
196 	a->format_options = archive_write_ustar_options;
197 	a->format_write_header = archive_write_ustar_header;
198 	a->format_write_data = archive_write_ustar_data;
199 	a->format_close = archive_write_ustar_close;
200 	a->format_free = archive_write_ustar_free;
201 	a->format_finish_entry = archive_write_ustar_finish_entry;
202 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_USTAR;
203 	a->archive.archive_format_name = "POSIX ustar";
204 	return (ARCHIVE_OK);
205 }
206 
207 static int
208 archive_write_ustar_options(struct archive_write *a, const char *key,
209     const char *val)
210 {
211 	struct ustar *ustar = (struct ustar *)a->format_data;
212 	int ret = ARCHIVE_FAILED;
213 
214 	if (strcmp(key, "hdrcharset")  == 0) {
215 		if (val == NULL || val[0] == 0)
216 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
217 			    "%s: hdrcharset option needs a character-set name",
218 			    a->format_name);
219 		else {
220 			ustar->opt_sconv = archive_string_conversion_to_charset(
221 			    &a->archive, val, 0);
222 			if (ustar->opt_sconv != NULL)
223 				ret = ARCHIVE_OK;
224 			else
225 				ret = ARCHIVE_FATAL;
226 		}
227 		return (ret);
228 	}
229 
230 	/* Note: The "warn" return is just to inform the options
231 	 * supervisor that we didn't handle it.  It will generate
232 	 * a suitable error if no one used this option. */
233 	return (ARCHIVE_WARN);
234 }
235 
236 static int
237 archive_write_ustar_header(struct archive_write *a, struct archive_entry *entry)
238 {
239 	char buff[512];
240 	int ret, ret2;
241 	struct ustar *ustar;
242 	struct archive_entry *entry_main;
243 	struct archive_string_conv *sconv;
244 
245 	ustar = (struct ustar *)a->format_data;
246 
247 	/* Setup default string conversion. */
248 	if (ustar->opt_sconv == NULL) {
249 		if (!ustar->init_default_conversion) {
250 			ustar->sconv_default =
251 			    archive_string_default_conversion_for_write(&(a->archive));
252 			ustar->init_default_conversion = 1;
253 		}
254 		sconv = ustar->sconv_default;
255 	} else
256 		sconv = ustar->opt_sconv;
257 
258 	/* Sanity check. */
259 	if (archive_entry_pathname(entry) == NULL) {
260 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
261 		    "Can't record entry in tar file without pathname");
262 		return (ARCHIVE_FAILED);
263 	}
264 
265 	/* Only regular files (not hardlinks) have data. */
266 	if (archive_entry_hardlink(entry) != NULL ||
267 	    archive_entry_symlink(entry) != NULL ||
268 	    !(archive_entry_filetype(entry) == AE_IFREG))
269 		archive_entry_set_size(entry, 0);
270 
271 	if (AE_IFDIR == archive_entry_filetype(entry)) {
272 		const char *p;
273 		size_t path_length;
274 		/*
275 		 * Ensure a trailing '/'.  Modify the entry so
276 		 * the client sees the change.
277 		 */
278 #if defined(_WIN32) && !defined(__CYGWIN__)
279 		const wchar_t *wp;
280 
281 		wp = archive_entry_pathname_w(entry);
282 		if (wp != NULL && wp[wcslen(wp) -1] != L'/') {
283 			struct archive_wstring ws;
284 
285 			archive_string_init(&ws);
286 			path_length = wcslen(wp);
287 			if (archive_wstring_ensure(&ws,
288 			    path_length + 2) == NULL) {
289 				archive_set_error(&a->archive, ENOMEM,
290 				    "Can't allocate ustar data");
291 				archive_wstring_free(&ws);
292 				return(ARCHIVE_FATAL);
293 			}
294 			/* Should we keep '\' ? */
295 			if (wp[path_length -1] == L'\\')
296 				path_length--;
297 			archive_wstrncpy(&ws, wp, path_length);
298 			archive_wstrappend_wchar(&ws, L'/');
299 			archive_entry_copy_pathname_w(entry, ws.s);
300 			archive_wstring_free(&ws);
301 			p = NULL;
302 		} else
303 #endif
304 			p = archive_entry_pathname(entry);
305 		/*
306 		 * On Windows, this is a backup operation just in
307 		 * case getting WCS failed. On POSIX, this is a
308 		 * normal operation.
309 		 */
310 		if (p != NULL && p[strlen(p) - 1] != '/') {
311 			struct archive_string as;
312 
313 			archive_string_init(&as);
314 			path_length = strlen(p);
315 			if (archive_string_ensure(&as,
316 			    path_length + 2) == NULL) {
317 				archive_set_error(&a->archive, ENOMEM,
318 				    "Can't allocate ustar data");
319 				archive_string_free(&as);
320 				return(ARCHIVE_FATAL);
321 			}
322 #if defined(_WIN32) && !defined(__CYGWIN__)
323 			/* NOTE: This might break the pathname
324 			 * if the current code page is CP932 and
325 			 * the pathname includes a character '\'
326 			 * as a part of its multibyte pathname. */
327 			if (p[strlen(p) -1] == '\\')
328 				path_length--;
329 			else
330 #endif
331 			archive_strncpy(&as, p, path_length);
332 			archive_strappend_char(&as, '/');
333 			archive_entry_copy_pathname(entry, as.s);
334 			archive_string_free(&as);
335 		}
336 	}
337 
338 #if defined(_WIN32) && !defined(__CYGWIN__)
339 	/* Make sure the path separators in pahtname, hardlink and symlink
340 	 * are all slash '/', not the Windows path separator '\'. */
341 	entry_main = __la_win_entry_in_posix_pathseparator(entry);
342 	if (entry_main == NULL) {
343 		archive_set_error(&a->archive, ENOMEM,
344 		    "Can't allocate ustar data");
345 		return(ARCHIVE_FATAL);
346 	}
347 	if (entry != entry_main)
348 		entry = entry_main;
349 	else
350 		entry_main = NULL;
351 #else
352 	entry_main = NULL;
353 #endif
354 	ret = __archive_write_format_header_ustar(a, buff, entry, -1, 1, sconv);
355 	if (ret < ARCHIVE_WARN) {
356 		if (entry_main)
357 			archive_entry_free(entry_main);
358 		return (ret);
359 	}
360 	ret2 = __archive_write_output(a, buff, 512);
361 	if (ret2 < ARCHIVE_WARN) {
362 		if (entry_main)
363 			archive_entry_free(entry_main);
364 		return (ret2);
365 	}
366 	if (ret2 < ret)
367 		ret = ret2;
368 
369 	ustar->entry_bytes_remaining = archive_entry_size(entry);
370 	ustar->entry_padding = 0x1ff & (-(int64_t)ustar->entry_bytes_remaining);
371 	if (entry_main)
372 		archive_entry_free(entry_main);
373 	return (ret);
374 }
375 
376 /*
377  * Format a basic 512-byte "ustar" header.
378  *
379  * Returns -1 if format failed (due to field overflow).
380  * Note that this always formats as much of the header as possible.
381  * If "strict" is set to zero, it will extend numeric fields as
382  * necessary (overwriting terminators or using base-256 extensions).
383  *
384  * This is exported so that other 'tar' formats can use it.
385  */
386 int
387 __archive_write_format_header_ustar(struct archive_write *a, char h[512],
388     struct archive_entry *entry, int tartype, int strict,
389     struct archive_string_conv *sconv)
390 {
391 	unsigned int checksum;
392 	int i, r, ret;
393 	size_t copy_length;
394 	const char *p, *pp;
395 	int mytartype;
396 
397 	ret = 0;
398 	mytartype = -1;
399 	/*
400 	 * The "template header" already includes the "ustar"
401 	 * signature, various end-of-field markers and other required
402 	 * elements.
403 	 */
404 	memcpy(h, &template_header, 512);
405 
406 	/*
407 	 * Because the block is already null-filled, and strings
408 	 * are allowed to exactly fill their destination (without null),
409 	 * I use memcpy(dest, src, strlen()) here a lot to copy strings.
410 	 */
411 	r = archive_entry_pathname_l(entry, &pp, &copy_length, sconv);
412 	if (r != 0) {
413 		if (errno == ENOMEM) {
414 			archive_set_error(&a->archive, ENOMEM,
415 			    "Can't allocate memory for Pathname");
416 			return (ARCHIVE_FATAL);
417 		}
418 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
419 		    "Can't translate pathname '%s' to %s",
420 		    pp, archive_string_conversion_charset_name(sconv));
421 		ret = ARCHIVE_WARN;
422 	}
423 	if (copy_length <= USTAR_name_size)
424 		memcpy(h + USTAR_name_offset, pp, copy_length);
425 	else {
426 		/* Store in two pieces, splitting at a '/'. */
427 		p = strchr(pp + copy_length - USTAR_name_size - 1, '/');
428 		/*
429 		 * Look for the next '/' if we chose the first character
430 		 * as the separator.  (ustar format doesn't permit
431 		 * an empty prefix.)
432 		 */
433 		if (p == pp)
434 			p = strchr(p + 1, '/');
435 		/* Fail if the name won't fit. */
436 		if (!p) {
437 			/* No separator. */
438 			archive_set_error(&a->archive, ENAMETOOLONG,
439 			    "Pathname too long");
440 			ret = ARCHIVE_FAILED;
441 		} else if (p[1] == '\0') {
442 			/*
443 			 * The only feasible separator is a final '/';
444 			 * this would result in a non-empty prefix and
445 			 * an empty name, which POSIX doesn't
446 			 * explicitly forbid, but it just feels wrong.
447 			 */
448 			archive_set_error(&a->archive, ENAMETOOLONG,
449 			    "Pathname too long");
450 			ret = ARCHIVE_FAILED;
451 		} else if (p  > pp + USTAR_prefix_size) {
452 			/* Prefix is too long. */
453 			archive_set_error(&a->archive, ENAMETOOLONG,
454 			    "Pathname too long");
455 			ret = ARCHIVE_FAILED;
456 		} else {
457 			/* Copy prefix and remainder to appropriate places */
458 			memcpy(h + USTAR_prefix_offset, pp, p - pp);
459 			memcpy(h + USTAR_name_offset, p + 1,
460 			    pp + copy_length - p - 1);
461 		}
462 	}
463 
464 	r = archive_entry_hardlink_l(entry, &p, &copy_length, sconv);
465 	if (r != 0) {
466 		if (errno == ENOMEM) {
467 			archive_set_error(&a->archive, ENOMEM,
468 			    "Can't allocate memory for Linkname");
469 			return (ARCHIVE_FATAL);
470 		}
471 		archive_set_error(&a->archive,
472 		    ARCHIVE_ERRNO_FILE_FORMAT,
473 		    "Can't translate linkname '%s' to %s",
474 		    p, archive_string_conversion_charset_name(sconv));
475 		ret = ARCHIVE_WARN;
476 	}
477 	if (copy_length > 0)
478 		mytartype = '1';
479 	else {
480 		r = archive_entry_symlink_l(entry, &p, &copy_length, sconv);
481 		if (r != 0) {
482 			if (errno == ENOMEM) {
483 				archive_set_error(&a->archive, ENOMEM,
484 				    "Can't allocate memory for Linkname");
485 				return (ARCHIVE_FATAL);
486 			}
487 			archive_set_error(&a->archive,
488 			    ARCHIVE_ERRNO_FILE_FORMAT,
489 			    "Can't translate linkname '%s' to %s",
490 			    p, archive_string_conversion_charset_name(sconv));
491 			ret = ARCHIVE_WARN;
492 		}
493 	}
494 	if (copy_length > 0) {
495 		if (copy_length > USTAR_linkname_size) {
496 			archive_set_error(&a->archive, ENAMETOOLONG,
497 			    "Link contents too long");
498 			ret = ARCHIVE_FAILED;
499 			copy_length = USTAR_linkname_size;
500 		}
501 		memcpy(h + USTAR_linkname_offset, p, copy_length);
502 	}
503 
504 	r = archive_entry_uname_l(entry, &p, &copy_length, sconv);
505 	if (r != 0) {
506 		if (errno == ENOMEM) {
507 			archive_set_error(&a->archive, ENOMEM,
508 			    "Can't allocate memory for Uname");
509 			return (ARCHIVE_FATAL);
510 		}
511 		archive_set_error(&a->archive,
512 		    ARCHIVE_ERRNO_FILE_FORMAT,
513 		    "Can't translate uname '%s' to %s",
514 		    p, archive_string_conversion_charset_name(sconv));
515 		ret = ARCHIVE_WARN;
516 	}
517 	if (copy_length > 0) {
518 		if (copy_length > USTAR_uname_size) {
519 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
520 			    "Username too long");
521 			ret = ARCHIVE_FAILED;
522 			copy_length = USTAR_uname_size;
523 		}
524 		memcpy(h + USTAR_uname_offset, p, copy_length);
525 	}
526 
527 	r = archive_entry_gname_l(entry, &p, &copy_length, sconv);
528 	if (r != 0) {
529 		if (errno == ENOMEM) {
530 			archive_set_error(&a->archive, ENOMEM,
531 			    "Can't allocate memory for Gname");
532 			return (ARCHIVE_FATAL);
533 		}
534 		archive_set_error(&a->archive,
535 		    ARCHIVE_ERRNO_FILE_FORMAT,
536 		    "Can't translate gname '%s' to %s",
537 		    p, archive_string_conversion_charset_name(sconv));
538 		ret = ARCHIVE_WARN;
539 	}
540 	if (copy_length > 0) {
541 		if (strlen(p) > USTAR_gname_size) {
542 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
543 			    "Group name too long");
544 			ret = ARCHIVE_FAILED;
545 			copy_length = USTAR_gname_size;
546 		}
547 		memcpy(h + USTAR_gname_offset, p, copy_length);
548 	}
549 
550 	if (format_number(archive_entry_mode(entry) & 07777,
551 	    h + USTAR_mode_offset, USTAR_mode_size, USTAR_mode_max_size, strict)) {
552 		archive_set_error(&a->archive, ERANGE,
553 		    "Numeric mode too large");
554 		ret = ARCHIVE_FAILED;
555 	}
556 
557 	if (format_number(archive_entry_uid(entry),
558 	    h + USTAR_uid_offset, USTAR_uid_size, USTAR_uid_max_size, strict)) {
559 		archive_set_error(&a->archive, ERANGE,
560 		    "Numeric user ID too large");
561 		ret = ARCHIVE_FAILED;
562 	}
563 
564 	if (format_number(archive_entry_gid(entry),
565 	    h + USTAR_gid_offset, USTAR_gid_size, USTAR_gid_max_size, strict)) {
566 		archive_set_error(&a->archive, ERANGE,
567 		    "Numeric group ID too large");
568 		ret = ARCHIVE_FAILED;
569 	}
570 
571 	if (format_number(archive_entry_size(entry),
572 	    h + USTAR_size_offset, USTAR_size_size, USTAR_size_max_size, strict)) {
573 		archive_set_error(&a->archive, ERANGE,
574 		    "File size out of range");
575 		ret = ARCHIVE_FAILED;
576 	}
577 
578 	if (format_number(archive_entry_mtime(entry),
579 	    h + USTAR_mtime_offset, USTAR_mtime_size, USTAR_mtime_max_size, strict)) {
580 		archive_set_error(&a->archive, ERANGE,
581 		    "File modification time too large");
582 		ret = ARCHIVE_FAILED;
583 	}
584 
585 	if (archive_entry_filetype(entry) == AE_IFBLK
586 	    || archive_entry_filetype(entry) == AE_IFCHR) {
587 		if (format_number(archive_entry_rdevmajor(entry),
588 		    h + USTAR_rdevmajor_offset, USTAR_rdevmajor_size,
589 		    USTAR_rdevmajor_max_size, strict)) {
590 			archive_set_error(&a->archive, ERANGE,
591 			    "Major device number too large");
592 			ret = ARCHIVE_FAILED;
593 		}
594 
595 		if (format_number(archive_entry_rdevminor(entry),
596 		    h + USTAR_rdevminor_offset, USTAR_rdevminor_size,
597 		    USTAR_rdevminor_max_size, strict)) {
598 			archive_set_error(&a->archive, ERANGE,
599 			    "Minor device number too large");
600 			ret = ARCHIVE_FAILED;
601 		}
602 	}
603 
604 	if (tartype >= 0) {
605 		h[USTAR_typeflag_offset] = tartype;
606 	} else if (mytartype >= 0) {
607 		h[USTAR_typeflag_offset] = mytartype;
608 	} else {
609 		switch (archive_entry_filetype(entry)) {
610 		case AE_IFREG: h[USTAR_typeflag_offset] = '0' ; break;
611 		case AE_IFLNK: h[USTAR_typeflag_offset] = '2' ; break;
612 		case AE_IFCHR: h[USTAR_typeflag_offset] = '3' ; break;
613 		case AE_IFBLK: h[USTAR_typeflag_offset] = '4' ; break;
614 		case AE_IFDIR: h[USTAR_typeflag_offset] = '5' ; break;
615 		case AE_IFIFO: h[USTAR_typeflag_offset] = '6' ; break;
616 		case AE_IFSOCK:
617 			archive_set_error(&a->archive,
618 			    ARCHIVE_ERRNO_FILE_FORMAT,
619 			    "tar format cannot archive socket");
620 			return (ARCHIVE_FAILED);
621 		default:
622 			archive_set_error(&a->archive,
623 			    ARCHIVE_ERRNO_FILE_FORMAT,
624 			    "tar format cannot archive this (mode=0%lo)",
625 			    (unsigned long)archive_entry_mode(entry));
626 			ret = ARCHIVE_FAILED;
627 		}
628 	}
629 
630 	checksum = 0;
631 	for (i = 0; i < 512; i++)
632 		checksum += 255 & (unsigned int)h[i];
633 	h[USTAR_checksum_offset + 6] = '\0'; /* Can't be pre-set in the template. */
634 	/* h[USTAR_checksum_offset + 7] = ' '; */ /* This is pre-set in the template. */
635 	format_octal(checksum, h + USTAR_checksum_offset, 6);
636 	return (ret);
637 }
638 
639 /*
640  * Format a number into a field, with some intelligence.
641  */
642 static int
643 format_number(int64_t v, char *p, int s, int maxsize, int strict)
644 {
645 	int64_t limit;
646 
647 	limit = ((int64_t)1 << (s*3));
648 
649 	/* "Strict" only permits octal values with proper termination. */
650 	if (strict)
651 		return (format_octal(v, p, s));
652 
653 	/*
654 	 * In non-strict mode, we allow the number to overwrite one or
655 	 * more bytes of the field termination.  Even old tar
656 	 * implementations should be able to handle this with no
657 	 * problem.
658 	 */
659 	if (v >= 0) {
660 		while (s <= maxsize) {
661 			if (v < limit)
662 				return (format_octal(v, p, s));
663 			s++;
664 			limit <<= 3;
665 		}
666 	}
667 
668 	/* Base-256 can handle any number, positive or negative. */
669 	return (format_256(v, p, maxsize));
670 }
671 
672 /*
673  * Format a number into the specified field using base-256.
674  */
675 static int
676 format_256(int64_t v, char *p, int s)
677 {
678 	p += s;
679 	while (s-- > 0) {
680 		*--p = (char)(v & 0xff);
681 		v >>= 8;
682 	}
683 	*p |= 0x80; /* Set the base-256 marker bit. */
684 	return (0);
685 }
686 
687 /*
688  * Format a number into the specified field.
689  */
690 static int
691 format_octal(int64_t v, char *p, int s)
692 {
693 	int len;
694 
695 	len = s;
696 
697 	/* Octal values can't be negative, so use 0. */
698 	if (v < 0) {
699 		while (len-- > 0)
700 			*p++ = '0';
701 		return (-1);
702 	}
703 
704 	p += s;		/* Start at the end and work backwards. */
705 	while (s-- > 0) {
706 		*--p = (char)('0' + (v & 7));
707 		v >>= 3;
708 	}
709 
710 	if (v == 0)
711 		return (0);
712 
713 	/* If it overflowed, fill field with max value. */
714 	while (len-- > 0)
715 		*p++ = '7';
716 
717 	return (-1);
718 }
719 
720 static int
721 archive_write_ustar_close(struct archive_write *a)
722 {
723 	return (__archive_write_nulls(a, 512*2));
724 }
725 
726 static int
727 archive_write_ustar_free(struct archive_write *a)
728 {
729 	struct ustar *ustar;
730 
731 	ustar = (struct ustar *)a->format_data;
732 	free(ustar);
733 	a->format_data = NULL;
734 	return (ARCHIVE_OK);
735 }
736 
737 static int
738 archive_write_ustar_finish_entry(struct archive_write *a)
739 {
740 	struct ustar *ustar;
741 	int ret;
742 
743 	ustar = (struct ustar *)a->format_data;
744 	ret = __archive_write_nulls(a,
745 	    (size_t)(ustar->entry_bytes_remaining + ustar->entry_padding));
746 	ustar->entry_bytes_remaining = ustar->entry_padding = 0;
747 	return (ret);
748 }
749 
750 static ssize_t
751 archive_write_ustar_data(struct archive_write *a, const void *buff, size_t s)
752 {
753 	struct ustar *ustar;
754 	int ret;
755 
756 	ustar = (struct ustar *)a->format_data;
757 	if (s > ustar->entry_bytes_remaining)
758 		s = (size_t)ustar->entry_bytes_remaining;
759 	ret = __archive_write_output(a, buff, s);
760 	ustar->entry_bytes_remaining -= s;
761 	if (ret != ARCHIVE_OK)
762 		return (ret);
763 	return (s);
764 }
765