xref: /freebsd/contrib/libarchive/libarchive/archive_write_set_format_pax.c (revision bd66c1b43e33540205dbc1187c2f2a15c58b57ba)
1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * Copyright (c) 2010-2012 Michihiro NAKAJIMA
4  * Copyright (c) 2016 Martin Matuska
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "archive_platform.h"
29 
30 #ifdef HAVE_ERRNO_H
31 #include <errno.h>
32 #endif
33 #ifdef HAVE_STDLIB_H
34 #include <stdlib.h>
35 #endif
36 #ifdef HAVE_STRING_H
37 #include <string.h>
38 #endif
39 
40 #include "archive.h"
41 #include "archive_entry.h"
42 #include "archive_entry_locale.h"
43 #include "archive_private.h"
44 #include "archive_write_private.h"
45 #include "archive_write_set_format_private.h"
46 
47 struct sparse_block {
48 	struct sparse_block	*next;
49 	int		is_hole;
50 	uint64_t	offset;
51 	uint64_t	remaining;
52 };
53 
54 struct pax {
55 	uint64_t	entry_bytes_remaining;
56 	uint64_t	entry_padding;
57 	struct archive_string	l_url_encoded_name;
58 	struct archive_string	pax_header;
59 	struct archive_string	sparse_map;
60 	size_t			sparse_map_padding;
61 	struct sparse_block	*sparse_list;
62 	struct sparse_block	*sparse_tail;
63 	struct archive_string_conv *sconv_utf8;
64 	int			 opt_binary;
65 
66 	unsigned flags;
67 #define WRITE_SCHILY_XATTR       (1 << 0)
68 #define WRITE_LIBARCHIVE_XATTR   (1 << 1)
69 };
70 
71 static void		 add_pax_attr(struct archive_string *, const char *key,
72 			     const char *value);
73 static void		 add_pax_attr_binary(struct archive_string *,
74 			     const char *key,
75 			     const char *value, size_t value_len);
76 static void		 add_pax_attr_int(struct archive_string *,
77 			     const char *key, int64_t value);
78 static void		 add_pax_attr_time(struct archive_string *,
79 			     const char *key, int64_t sec,
80 			     unsigned long nanos);
81 static int		 add_pax_acl(struct archive_write *,
82 			    struct archive_entry *, struct pax *, int);
83 static ssize_t		 archive_write_pax_data(struct archive_write *,
84 			     const void *, size_t);
85 static int		 archive_write_pax_close(struct archive_write *);
86 static int		 archive_write_pax_free(struct archive_write *);
87 static int		 archive_write_pax_finish_entry(struct archive_write *);
88 static int		 archive_write_pax_header(struct archive_write *,
89 			     struct archive_entry *);
90 static int		 archive_write_pax_options(struct archive_write *,
91 			     const char *, const char *);
92 static char		*base64_encode(const char *src, size_t len);
93 static char		*build_gnu_sparse_name(char *dest, const char *src);
94 static char		*build_pax_attribute_name(char *dest, const char *src);
95 static char		*build_ustar_entry_name(char *dest, const char *src,
96 			     size_t src_length, const char *insert);
97 static char		*format_int(char *dest, int64_t);
98 static int		 has_non_ASCII(const char *);
99 static void		 sparse_list_clear(struct pax *);
100 static int		 sparse_list_add(struct pax *, int64_t, int64_t);
101 static char		*url_encode(const char *in);
102 static time_t		 get_ustar_max_mtime(void);
103 
104 /*
105  * Set output format to 'restricted pax' format.
106  *
107  * This is the same as normal 'pax', but tries to suppress
108  * the pax header whenever possible.  This is the default for
109  * bsdtar, for instance.
110  */
111 int
archive_write_set_format_pax_restricted(struct archive * _a)112 archive_write_set_format_pax_restricted(struct archive *_a)
113 {
114 	struct archive_write *a = (struct archive_write *)_a;
115 	int r;
116 
117 	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
118 	    ARCHIVE_STATE_NEW, "archive_write_set_format_pax_restricted");
119 
120 	r = archive_write_set_format_pax(&a->archive);
121 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_RESTRICTED;
122 	a->archive.archive_format_name = "restricted POSIX pax interchange";
123 	return (r);
124 }
125 
126 /*
127  * Set output format to 'pax' format.
128  */
129 int
archive_write_set_format_pax(struct archive * _a)130 archive_write_set_format_pax(struct archive *_a)
131 {
132 	struct archive_write *a = (struct archive_write *)_a;
133 	struct pax *pax;
134 
135 	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
136 	    ARCHIVE_STATE_NEW, "archive_write_set_format_pax");
137 
138 	if (a->format_free != NULL)
139 		(a->format_free)(a);
140 
141 	pax = calloc(1, sizeof(*pax));
142 	if (pax == NULL) {
143 		archive_set_error(&a->archive, ENOMEM,
144 		    "Can't allocate pax data");
145 		return (ARCHIVE_FATAL);
146 	}
147 	pax->flags = WRITE_LIBARCHIVE_XATTR | WRITE_SCHILY_XATTR;
148 
149 	a->format_data = pax;
150 	a->format_name = "pax";
151 	a->format_options = archive_write_pax_options;
152 	a->format_write_header = archive_write_pax_header;
153 	a->format_write_data = archive_write_pax_data;
154 	a->format_close = archive_write_pax_close;
155 	a->format_free = archive_write_pax_free;
156 	a->format_finish_entry = archive_write_pax_finish_entry;
157 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
158 	a->archive.archive_format_name = "POSIX pax interchange";
159 	return (ARCHIVE_OK);
160 }
161 
162 static int
archive_write_pax_options(struct archive_write * a,const char * key,const char * val)163 archive_write_pax_options(struct archive_write *a, const char *key,
164     const char *val)
165 {
166 	struct pax *pax = (struct pax *)a->format_data;
167 	int ret = ARCHIVE_FAILED;
168 
169 	if (strcmp(key, "hdrcharset")  == 0) {
170 		/*
171 		 * The character-set we can use are defined in
172 		 * IEEE Std 1003.1-2001
173 		 */
174 		if (val == NULL || val[0] == 0)
175 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
176 			    "pax: hdrcharset option needs a character-set name");
177 		else if (strcmp(val, "BINARY") == 0 ||
178 		    strcmp(val, "binary") == 0) {
179 			/*
180 			 * Specify binary mode. We will not convert
181 			 * filenames, uname and gname to any charsets.
182 			 */
183 			pax->opt_binary = 1;
184 			ret = ARCHIVE_OK;
185 		} else if (strcmp(val, "UTF-8") == 0) {
186 			/*
187 			 * Specify UTF-8 character-set to be used for
188 			 * filenames. This is almost the test that
189 			 * running platform supports the string conversion.
190 			 * Especially libarchive_test needs this trick for
191 			 * its test.
192 			 */
193 			pax->sconv_utf8 = archive_string_conversion_to_charset(
194 			    &(a->archive), "UTF-8", 0);
195 			if (pax->sconv_utf8 == NULL)
196 				ret = ARCHIVE_FATAL;
197 			else
198 				ret = ARCHIVE_OK;
199 		} else
200 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
201 			    "pax: invalid charset name");
202 		return (ret);
203 	} else if (strcmp(key, "xattrheader") == 0) {
204 		if (val == NULL || val[0] == 0) {
205 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
206 			    "pax: xattrheader requires a value");
207 		} else if (strcmp(val, "ALL") == 0 ||
208 		    strcmp(val, "all") == 0) {
209 			pax->flags |= WRITE_LIBARCHIVE_XATTR | WRITE_SCHILY_XATTR;
210 			ret = ARCHIVE_OK;
211 		} else if (strcmp(val, "SCHILY") == 0 ||
212 		    strcmp(val, "schily") == 0) {
213 			pax->flags |= WRITE_SCHILY_XATTR;
214 			pax->flags &= ~WRITE_LIBARCHIVE_XATTR;
215 			ret = ARCHIVE_OK;
216 		} else if (strcmp(val, "LIBARCHIVE") == 0 ||
217 		    strcmp(val, "libarchive") == 0) {
218 			pax->flags |= WRITE_LIBARCHIVE_XATTR;
219 			pax->flags &= ~WRITE_SCHILY_XATTR;
220 			ret = ARCHIVE_OK;
221 		} else
222 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
223 			    "pax: invalid xattr header name");
224 		return (ret);
225 	}
226 
227 	/* Note: The "warn" return is just to inform the options
228 	 * supervisor that we didn't handle it.  It will generate
229 	 * a suitable error if no one used this option. */
230 	return (ARCHIVE_WARN);
231 }
232 
233 /*
234  * Note: This code assumes that 'nanos' has the same sign as 'sec',
235  * which implies that sec=-1, nanos=200000000 represents -1.2 seconds
236  * and not -0.8 seconds.  This is a pretty pedantic point, as we're
237  * unlikely to encounter many real files created before Jan 1, 1970,
238  * much less ones with timestamps recorded to sub-second resolution.
239  */
240 static void
add_pax_attr_time(struct archive_string * as,const char * key,int64_t sec,unsigned long nanos)241 add_pax_attr_time(struct archive_string *as, const char *key,
242     int64_t sec, unsigned long nanos)
243 {
244 	int digit, i;
245 	char *t;
246 	/*
247 	 * Note that each byte contributes fewer than 3 base-10
248 	 * digits, so this will always be big enough.
249 	 */
250 	char tmp[1 + 3*sizeof(sec) + 1 + 3*sizeof(nanos)];
251 
252 	tmp[sizeof(tmp) - 1] = 0;
253 	t = tmp + sizeof(tmp) - 1;
254 
255 	/* Skip trailing zeros in the fractional part. */
256 	for (digit = 0, i = 10; i > 0 && digit == 0; i--) {
257 		digit = nanos % 10;
258 		nanos /= 10;
259 	}
260 
261 	/* Only format the fraction if it's non-zero. */
262 	if (i > 0) {
263 		while (i > 0) {
264 			*--t = "0123456789"[digit];
265 			digit = nanos % 10;
266 			nanos /= 10;
267 			i--;
268 		}
269 		*--t = '.';
270 	}
271 	t = format_int(t, sec);
272 
273 	add_pax_attr(as, key, t);
274 }
275 
276 static char *
format_int(char * t,int64_t i)277 format_int(char *t, int64_t i)
278 {
279 	uint64_t ui;
280 
281 	if (i < 0)
282 		ui = (i == INT64_MIN) ? (uint64_t)(INT64_MAX) + 1 : (uint64_t)(-i);
283 	else
284 		ui = i;
285 
286 	do {
287 		*--t = "0123456789"[ui % 10];
288 	} while (ui /= 10);
289 	if (i < 0)
290 		*--t = '-';
291 	return (t);
292 }
293 
294 static void
add_pax_attr_int(struct archive_string * as,const char * key,int64_t value)295 add_pax_attr_int(struct archive_string *as, const char *key, int64_t value)
296 {
297 	char tmp[1 + 3 * sizeof(value)];
298 
299 	tmp[sizeof(tmp) - 1] = 0;
300 	add_pax_attr(as, key, format_int(tmp + sizeof(tmp) - 1, value));
301 }
302 
303 /*
304  * Add a key/value attribute to the pax header.  This function handles
305  * the length field and various other syntactic requirements.
306  */
307 static void
add_pax_attr(struct archive_string * as,const char * key,const char * value)308 add_pax_attr(struct archive_string *as, const char *key, const char *value)
309 {
310 	add_pax_attr_binary(as, key, value, strlen(value));
311 }
312 
313 /*
314  * Add a key/value attribute to the pax header.  This function handles
315  * binary values.
316  */
317 static void
add_pax_attr_binary(struct archive_string * as,const char * key,const char * value,size_t value_len)318 add_pax_attr_binary(struct archive_string *as, const char *key,
319 		    const char *value, size_t value_len)
320 {
321 	int digits, i, len, next_ten;
322 	char tmp[1 + 3 * sizeof(int)];	/* < 3 base-10 digits per byte */
323 
324 	/*-
325 	 * PAX attributes have the following layout:
326 	 *     <len> <space> <key> <=> <value> <nl>
327 	 */
328 	len = 1 + (int)strlen(key) + 1 + (int)value_len + 1;
329 
330 	/*
331 	 * The <len> field includes the length of the <len> field, so
332 	 * computing the correct length is tricky.  I start by
333 	 * counting the number of base-10 digits in 'len' and
334 	 * computing the next higher power of 10.
335 	 */
336 	next_ten = 1;
337 	digits = 0;
338 	i = len;
339 	while (i > 0) {
340 		i = i / 10;
341 		digits++;
342 		next_ten = next_ten * 10;
343 	}
344 	/*
345 	 * For example, if string without the length field is 99
346 	 * chars, then adding the 2 digit length "99" will force the
347 	 * total length past 100, requiring an extra digit.  The next
348 	 * statement adjusts for this effect.
349 	 */
350 	if (len + digits >= next_ten)
351 		digits++;
352 
353 	/* Now, we have the right length so we can build the line. */
354 	tmp[sizeof(tmp) - 1] = 0;	/* Null-terminate the work area. */
355 	archive_strcat(as, format_int(tmp + sizeof(tmp) - 1, len + digits));
356 	archive_strappend_char(as, ' ');
357 	archive_strcat(as, key);
358 	archive_strappend_char(as, '=');
359 	archive_array_append(as, value, value_len);
360 	archive_strappend_char(as, '\n');
361 }
362 
363 static void
archive_write_pax_header_xattr(struct pax * pax,const char * encoded_name,const void * value,size_t value_len)364 archive_write_pax_header_xattr(struct pax *pax, const char *encoded_name,
365     const void *value, size_t value_len)
366 {
367 	struct archive_string s;
368 	char *encoded_value;
369 
370 	if (encoded_name == NULL)
371 		return;
372 
373 	if (pax->flags & WRITE_LIBARCHIVE_XATTR) {
374 		encoded_value = base64_encode((const char *)value, value_len);
375 		if (encoded_value != NULL) {
376 			archive_string_init(&s);
377 			archive_strcpy(&s, "LIBARCHIVE.xattr.");
378 			archive_strcat(&s, encoded_name);
379 			add_pax_attr(&(pax->pax_header), s.s, encoded_value);
380 			archive_string_free(&s);
381 		}
382 		free(encoded_value);
383 	}
384 	if (pax->flags & WRITE_SCHILY_XATTR) {
385 		archive_string_init(&s);
386 		archive_strcpy(&s, "SCHILY.xattr.");
387 		archive_strcat(&s, encoded_name);
388 		add_pax_attr_binary(&(pax->pax_header), s.s, value, value_len);
389 		archive_string_free(&s);
390 	}
391 }
392 
393 static int
archive_write_pax_header_xattrs(struct archive_write * a,struct pax * pax,struct archive_entry * entry)394 archive_write_pax_header_xattrs(struct archive_write *a,
395     struct pax *pax, struct archive_entry *entry)
396 {
397 	int i = archive_entry_xattr_reset(entry);
398 
399 	while (i--) {
400 		const char *name;
401 		const void *value;
402 		char *url_encoded_name = NULL, *encoded_name = NULL;
403 		size_t size;
404 		int r;
405 
406 		archive_entry_xattr_next(entry, &name, &value, &size);
407 		url_encoded_name = url_encode(name);
408 		if (url_encoded_name == NULL)
409 			goto malloc_error;
410 		else {
411 			/* Convert narrow-character to UTF-8. */
412 			r = archive_strcpy_l(&(pax->l_url_encoded_name),
413 			    url_encoded_name, pax->sconv_utf8);
414 			free(url_encoded_name); /* Done with this. */
415 			if (r == 0)
416 				encoded_name = pax->l_url_encoded_name.s;
417 			else if (r == -1)
418 				goto malloc_error;
419 			else {
420 				archive_set_error(&a->archive,
421 				    ARCHIVE_ERRNO_MISC,
422 				    "Error encoding pax extended attribute");
423 				return (ARCHIVE_FAILED);
424 			}
425 		}
426 
427 		archive_write_pax_header_xattr(pax, encoded_name,
428 		    value, size);
429 
430 	}
431 	return (ARCHIVE_OK);
432 malloc_error:
433 	archive_set_error(&a->archive, ENOMEM, "Can't allocate memory");
434 	return (ARCHIVE_FATAL);
435 }
436 
437 static int
get_entry_hardlink(struct archive_write * a,struct archive_entry * entry,const char ** name,size_t * length,struct archive_string_conv * sc)438 get_entry_hardlink(struct archive_write *a, struct archive_entry *entry,
439     const char **name, size_t *length, struct archive_string_conv *sc)
440 {
441 	int r;
442 
443 	r = archive_entry_hardlink_l(entry, name, length, sc);
444 	if (r != 0) {
445 		if (errno == ENOMEM) {
446 			archive_set_error(&a->archive, ENOMEM,
447 			    "Can't allocate memory for Linkname");
448 			return (ARCHIVE_FATAL);
449 		}
450 		return (ARCHIVE_WARN);
451 	}
452 	return (ARCHIVE_OK);
453 }
454 
455 static int
get_entry_pathname(struct archive_write * a,struct archive_entry * entry,const char ** name,size_t * length,struct archive_string_conv * sc)456 get_entry_pathname(struct archive_write *a, struct archive_entry *entry,
457     const char **name, size_t *length, struct archive_string_conv *sc)
458 {
459 	int r;
460 
461 	r = archive_entry_pathname_l(entry, name, length, sc);
462 	if (r != 0) {
463 		if (errno == ENOMEM) {
464 			archive_set_error(&a->archive, ENOMEM,
465 			    "Can't allocate memory for Pathname");
466 			return (ARCHIVE_FATAL);
467 		}
468 		return (ARCHIVE_WARN);
469 	}
470 	return (ARCHIVE_OK);
471 }
472 
473 static int
get_entry_uname(struct archive_write * a,struct archive_entry * entry,const char ** name,size_t * length,struct archive_string_conv * sc)474 get_entry_uname(struct archive_write *a, struct archive_entry *entry,
475     const char **name, size_t *length, struct archive_string_conv *sc)
476 {
477 	int r;
478 
479 	r = archive_entry_uname_l(entry, name, length, sc);
480 	if (r != 0) {
481 		if (errno == ENOMEM) {
482 			archive_set_error(&a->archive, ENOMEM,
483 			    "Can't allocate memory for Uname");
484 			return (ARCHIVE_FATAL);
485 		}
486 		return (ARCHIVE_WARN);
487 	}
488 	return (ARCHIVE_OK);
489 }
490 
491 static int
get_entry_gname(struct archive_write * a,struct archive_entry * entry,const char ** name,size_t * length,struct archive_string_conv * sc)492 get_entry_gname(struct archive_write *a, struct archive_entry *entry,
493     const char **name, size_t *length, struct archive_string_conv *sc)
494 {
495 	int r;
496 
497 	r = archive_entry_gname_l(entry, name, length, sc);
498 	if (r != 0) {
499 		if (errno == ENOMEM) {
500 			archive_set_error(&a->archive, ENOMEM,
501 			    "Can't allocate memory for Gname");
502 			return (ARCHIVE_FATAL);
503 		}
504 		return (ARCHIVE_WARN);
505 	}
506 	return (ARCHIVE_OK);
507 }
508 
509 static int
get_entry_symlink(struct archive_write * a,struct archive_entry * entry,const char ** name,size_t * length,struct archive_string_conv * sc)510 get_entry_symlink(struct archive_write *a, struct archive_entry *entry,
511     const char **name, size_t *length, struct archive_string_conv *sc)
512 {
513 	int r;
514 
515 	r = archive_entry_symlink_l(entry, name, length, sc);
516 	if (r != 0) {
517 		if (errno == ENOMEM) {
518 			archive_set_error(&a->archive, ENOMEM,
519 			    "Can't allocate memory for Linkname");
520 			return (ARCHIVE_FATAL);
521 		}
522 		return (ARCHIVE_WARN);
523 	}
524 	return (ARCHIVE_OK);
525 }
526 
527 /* Add ACL to pax header */
528 static int
add_pax_acl(struct archive_write * a,struct archive_entry * entry,struct pax * pax,int flags)529 add_pax_acl(struct archive_write *a,
530     struct archive_entry *entry, struct pax *pax, int flags)
531 {
532 	char *p;
533 	const char *attr;
534 	int acl_types;
535 
536 	acl_types = archive_entry_acl_types(entry);
537 
538 	if ((acl_types & ARCHIVE_ENTRY_ACL_TYPE_NFS4) != 0)
539 		attr = "SCHILY.acl.ace";
540 	else if ((flags & ARCHIVE_ENTRY_ACL_TYPE_ACCESS) != 0)
541 		attr = "SCHILY.acl.access";
542 	else if ((flags & ARCHIVE_ENTRY_ACL_TYPE_DEFAULT) != 0)
543 		attr = "SCHILY.acl.default";
544 	else
545 		return (ARCHIVE_FATAL);
546 
547 	p = archive_entry_acl_to_text_l(entry, NULL, flags, pax->sconv_utf8);
548 	if (p == NULL) {
549 		if (errno == ENOMEM) {
550 			archive_set_error(&a->archive, ENOMEM, "%s %s",
551 			    "Can't allocate memory for ", attr);
552 			return (ARCHIVE_FATAL);
553 		}
554 		archive_set_error(&a->archive,
555 		    ARCHIVE_ERRNO_FILE_FORMAT, "%s %s %s",
556 		    "Can't translate ", attr, " to UTF-8");
557 		return(ARCHIVE_WARN);
558 	}
559 
560 	if (*p != '\0') {
561 		add_pax_attr(&(pax->pax_header),
562 		    attr, p);
563 	}
564 	free(p);
565 	return(ARCHIVE_OK);
566 }
567 
568 /*
569  * TODO: Consider adding 'comment' and 'charset' fields to
570  * archive_entry so that clients can specify them.  Also, consider
571  * adding generic key/value tags so clients can add arbitrary
572  * key/value data.
573  *
574  * TODO: Break up this 700-line function!!!!  Yowza!
575  */
576 static int
archive_write_pax_header(struct archive_write * a,struct archive_entry * entry_original)577 archive_write_pax_header(struct archive_write *a,
578     struct archive_entry *entry_original)
579 {
580 	struct archive_entry *entry_main;
581 	const char *p;
582 	const char *suffix;
583 	int need_extension, r, ret;
584 	int acl_types;
585 	int sparse_count;
586 	uint64_t sparse_total, real_size;
587 	struct pax *pax;
588 	const char *hardlink;
589 	const char *path = NULL, *linkpath = NULL;
590 	const char *uname = NULL, *gname = NULL;
591 	const void *mac_metadata;
592 	size_t mac_metadata_size;
593 	struct archive_string_conv *sconv;
594 	size_t hardlink_length, path_length, linkpath_length;
595 	size_t uname_length, gname_length;
596 
597 	char paxbuff[512];
598 	char ustarbuff[512];
599 	char ustar_entry_name[256];
600 	char pax_entry_name[256];
601 	char gnu_sparse_name[256];
602 	struct archive_string entry_name;
603 
604 	ret = ARCHIVE_OK;
605 	need_extension = 0;
606 	pax = (struct pax *)a->format_data;
607 
608 	const time_t ustar_max_mtime = get_ustar_max_mtime();
609 
610 	/* Sanity check. */
611 #if defined(_WIN32) && !defined(__CYGWIN__)
612 	/* NOTE: If the caller supplied a pathname that fails WCS conversion (e.g.
613 	 * if it is invalid UTF-8), we are expected to return ARCHIVE_WARN later on
614 	 * in execution, hence the check for both pointers */
615 	if ((archive_entry_pathname_w(entry_original) == NULL) &&
616 	    (archive_entry_pathname(entry_original) == NULL)) {
617 #else
618 	if (archive_entry_pathname(entry_original) == NULL) {
619 #endif
620 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
621 			  "Can't record entry in tar file without pathname");
622 		return (ARCHIVE_FAILED);
623 	}
624 
625 	/*
626 	 * Choose a header encoding.
627 	 */
628 	if (pax->opt_binary)
629 		sconv = NULL;/* Binary mode. */
630 	else {
631 		/* Header encoding is UTF-8. */
632 		if (pax->sconv_utf8 == NULL) {
633 			/* Initialize the string conversion object
634 			 * we must need */
635 			pax->sconv_utf8 = archive_string_conversion_to_charset(
636 			    &(a->archive), "UTF-8", 1);
637 			if (pax->sconv_utf8 == NULL)
638 				/* Couldn't allocate memory */
639 				return (ARCHIVE_FAILED);
640 		}
641 		sconv = pax->sconv_utf8;
642 	}
643 
644 	r = get_entry_hardlink(a, entry_original, &hardlink,
645 	    &hardlink_length, sconv);
646 	if (r == ARCHIVE_FATAL)
647 		return (r);
648 	else if (r != ARCHIVE_OK) {
649 		r = get_entry_hardlink(a, entry_original, &hardlink,
650 		    &hardlink_length, NULL);
651 		if (r == ARCHIVE_FATAL)
652 			return (r);
653 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
654 		    "Can't translate linkname '%s' to %s", hardlink,
655 		    archive_string_conversion_charset_name(sconv));
656 		ret = ARCHIVE_WARN;
657 		sconv = NULL;/* The header charset switches to binary mode. */
658 	}
659 
660 	/* Make sure this is a type of entry that we can handle here */
661 	if (hardlink == NULL) {
662 		switch (archive_entry_filetype(entry_original)) {
663 		case AE_IFBLK:
664 		case AE_IFCHR:
665 		case AE_IFIFO:
666 		case AE_IFLNK:
667 		case AE_IFREG:
668 			break;
669 		case AE_IFDIR:
670 		{
671 			/*
672 			 * Ensure a trailing '/'.  Modify the original
673 			 * entry so the client sees the change.
674 			 */
675 #if defined(_WIN32) && !defined(__CYGWIN__)
676 			const wchar_t *wp;
677 
678 			wp = archive_entry_pathname_w(entry_original);
679 			if (wp != NULL && wp[wcslen(wp) -1] != L'/') {
680 				struct archive_wstring ws;
681 
682 				archive_string_init(&ws);
683 				path_length = wcslen(wp);
684 				if (archive_wstring_ensure(&ws,
685 				    path_length + 2) == NULL) {
686 					archive_set_error(&a->archive, ENOMEM,
687 					    "Can't allocate pax data");
688 					archive_wstring_free(&ws);
689 					return(ARCHIVE_FATAL);
690 				}
691 				/* Should we keep '\' ? */
692 				if (wp[path_length -1] == L'\\')
693 					path_length--;
694 				archive_wstrncpy(&ws, wp, path_length);
695 				archive_wstrappend_wchar(&ws, L'/');
696 				archive_entry_copy_pathname_w(
697 				    entry_original, ws.s);
698 				archive_wstring_free(&ws);
699 				p = NULL;
700 			} else
701 #endif
702 				p = archive_entry_pathname(entry_original);
703 			/*
704 			 * On Windows, this is a backup operation just in
705 			 * case getting WCS failed. On POSIX, this is a
706 			 * normal operation.
707 			 */
708 			if (p != NULL && p[0] != '\0' && p[strlen(p) - 1] != '/') {
709 				struct archive_string as;
710 
711 				archive_string_init(&as);
712 				path_length = strlen(p);
713 				if (archive_string_ensure(&as,
714 				    path_length + 2) == NULL) {
715 					archive_set_error(&a->archive, ENOMEM,
716 					    "Can't allocate pax data");
717 					archive_string_free(&as);
718 					return(ARCHIVE_FATAL);
719 				}
720 #if defined(_WIN32) && !defined(__CYGWIN__)
721 				/* NOTE: This might break the pathname
722 				 * if the current code page is CP932 and
723 				 * the pathname includes a character '\'
724 				 * as a part of its multibyte pathname. */
725 				if (p[strlen(p) -1] == '\\')
726 					path_length--;
727 				else
728 #endif
729 				archive_strncpy(&as, p, path_length);
730 				archive_strappend_char(&as, '/');
731 				archive_entry_copy_pathname(
732 				    entry_original, as.s);
733 				archive_string_free(&as);
734 			}
735 			break;
736 		}
737 		default: /* AE_IFSOCK and unknown */
738 			__archive_write_entry_filetype_unsupported(
739 			    &a->archive, entry_original, "pax");
740 			return (ARCHIVE_FAILED);
741 		}
742 	}
743 
744 	/*
745 	 * If Mac OS metadata blob is here, recurse to write that
746 	 * as a separate entry.  This is really a pretty poor design:
747 	 * In particular, it doubles the overhead for long filenames.
748 	 * TODO: Help Apple folks design something better and figure
749 	 * out how to transition from this legacy format.
750 	 *
751 	 * Note that this code is present on every platform; clients
752 	 * on non-Mac are unlikely to ever provide this data, but
753 	 * applications that copy entries from one archive to another
754 	 * should not lose data just because the local filesystem
755 	 * can't store it.
756 	 */
757 	mac_metadata =
758 	    archive_entry_mac_metadata(entry_original, &mac_metadata_size);
759 	if (mac_metadata != NULL) {
760 		const char *oname;
761 		char *name, *bname;
762 		size_t name_length;
763 		struct archive_entry *extra = archive_entry_new2(&a->archive);
764 
765 		oname = archive_entry_pathname(entry_original);
766 		name_length = strlen(oname);
767 		name = malloc(name_length + 3);
768 		if (name == NULL || extra == NULL) {
769 			/* XXX error message */
770 			archive_entry_free(extra);
771 			free(name);
772 			return (ARCHIVE_FAILED);
773 		}
774 		strcpy(name, oname);
775 		/* Find last '/'; strip trailing '/' characters */
776 		bname = strrchr(name, '/');
777 		while (bname != NULL && bname[1] == '\0') {
778 			*bname = '\0';
779 			bname = strrchr(name, '/');
780 		}
781 		if (bname == NULL) {
782 			memmove(name + 2, name, name_length + 1);
783 			memmove(name, "._", 2);
784 		} else {
785 			bname += 1;
786 			memmove(bname + 2, bname, strlen(bname) + 1);
787 			memmove(bname, "._", 2);
788 		}
789 		archive_entry_copy_pathname(extra, name);
790 		free(name);
791 
792 		archive_entry_set_size(extra, mac_metadata_size);
793 		archive_entry_set_filetype(extra, AE_IFREG);
794 		archive_entry_set_perm(extra,
795 		    archive_entry_perm(entry_original));
796 		archive_entry_set_mtime(extra,
797 		    archive_entry_mtime(entry_original),
798 		    archive_entry_mtime_nsec(entry_original));
799 		archive_entry_set_gid(extra,
800 		    archive_entry_gid(entry_original));
801 		archive_entry_set_gname(extra,
802 		    archive_entry_gname(entry_original));
803 		archive_entry_set_uid(extra,
804 		    archive_entry_uid(entry_original));
805 		archive_entry_set_uname(extra,
806 		    archive_entry_uname(entry_original));
807 
808 		/* Recurse to write the special copyfile entry. */
809 		r = archive_write_pax_header(a, extra);
810 		archive_entry_free(extra);
811 		if (r < ARCHIVE_WARN)
812 			return (r);
813 		if (r < ret)
814 			ret = r;
815 		r = (int)archive_write_pax_data(a, mac_metadata,
816 		    mac_metadata_size);
817 		if (r < ARCHIVE_WARN)
818 			return (r);
819 		if (r < ret)
820 			ret = r;
821 		r = archive_write_pax_finish_entry(a);
822 		if (r < ARCHIVE_WARN)
823 			return (r);
824 		if (r < ret)
825 			ret = r;
826 	}
827 
828 	/* Copy entry so we can modify it as needed. */
829 #if defined(_WIN32) && !defined(__CYGWIN__)
830 	/* Make sure the path separators in pathname, hardlink and symlink
831 	 * are all slash '/', not the Windows path separator '\'. */
832 	entry_main = __la_win_entry_in_posix_pathseparator(entry_original);
833 	if (entry_main == entry_original)
834 		entry_main = archive_entry_clone(entry_original);
835 #else
836 	entry_main = archive_entry_clone(entry_original);
837 #endif
838 	if (entry_main == NULL) {
839 		archive_set_error(&a->archive, ENOMEM,
840 		    "Can't allocate pax data");
841 		return(ARCHIVE_FATAL);
842 	}
843 	archive_string_empty(&(pax->pax_header)); /* Blank our work area. */
844 	archive_string_empty(&(pax->sparse_map));
845 	sparse_total = 0;
846 	sparse_list_clear(pax);
847 
848 	if (hardlink == NULL &&
849 	    archive_entry_filetype(entry_main) == AE_IFREG)
850 		sparse_count = archive_entry_sparse_reset(entry_main);
851 	else
852 		sparse_count = 0;
853 	if (sparse_count) {
854 		int64_t offset, length, last_offset = 0;
855 		/* Get the last entry of sparse block. */
856 		while (archive_entry_sparse_next(
857 		    entry_main, &offset, &length) == ARCHIVE_OK)
858 			last_offset = offset + length;
859 
860 		/* If the last sparse block does not reach the end of file,
861 		 * We have to add a empty sparse block as the last entry to
862 		 * manage storing file data. */
863 		if (last_offset < archive_entry_size(entry_main))
864 			archive_entry_sparse_add_entry(entry_main,
865 			    archive_entry_size(entry_main), 0);
866 		sparse_count = archive_entry_sparse_reset(entry_main);
867 	}
868 
869 	/*
870 	 * First, check the name fields and see if any of them
871 	 * require binary coding.  If any of them does, then all of
872 	 * them do.
873 	 */
874 	r = get_entry_pathname(a, entry_main, &path, &path_length, sconv);
875 	if (r == ARCHIVE_FATAL) {
876 		archive_entry_free(entry_main);
877 		return (r);
878 	} else if (r != ARCHIVE_OK) {
879 		r = get_entry_pathname(a, entry_main, &path,
880 		    &path_length, NULL);
881 		if (r == ARCHIVE_FATAL) {
882 			archive_entry_free(entry_main);
883 			return (r);
884 		}
885 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
886 		    "Can't translate pathname '%s' to %s", path,
887 		    archive_string_conversion_charset_name(sconv));
888 		ret = ARCHIVE_WARN;
889 		sconv = NULL;/* The header charset switches to binary mode. */
890 	}
891 	r = get_entry_uname(a, entry_main, &uname, &uname_length, sconv);
892 	if (r == ARCHIVE_FATAL) {
893 		archive_entry_free(entry_main);
894 		return (r);
895 	} else if (r != ARCHIVE_OK) {
896 		r = get_entry_uname(a, entry_main, &uname, &uname_length, NULL);
897 		if (r == ARCHIVE_FATAL) {
898 			archive_entry_free(entry_main);
899 			return (r);
900 		}
901 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
902 		    "Can't translate uname '%s' to %s", uname,
903 		    archive_string_conversion_charset_name(sconv));
904 		ret = ARCHIVE_WARN;
905 		sconv = NULL;/* The header charset switches to binary mode. */
906 	}
907 	r = get_entry_gname(a, entry_main, &gname, &gname_length, sconv);
908 	if (r == ARCHIVE_FATAL) {
909 		archive_entry_free(entry_main);
910 		return (r);
911 	} else if (r != ARCHIVE_OK) {
912 		r = get_entry_gname(a, entry_main, &gname, &gname_length, NULL);
913 		if (r == ARCHIVE_FATAL) {
914 			archive_entry_free(entry_main);
915 			return (r);
916 		}
917 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
918 		    "Can't translate gname '%s' to %s", gname,
919 		    archive_string_conversion_charset_name(sconv));
920 		ret = ARCHIVE_WARN;
921 		sconv = NULL;/* The header charset switches to binary mode. */
922 	}
923 	linkpath = hardlink;
924 	linkpath_length = hardlink_length;
925 	if (linkpath == NULL) {
926 		r = get_entry_symlink(a, entry_main, &linkpath,
927 		    &linkpath_length, sconv);
928 		if (r == ARCHIVE_FATAL) {
929 			archive_entry_free(entry_main);
930 			return (r);
931 		} else if (r != ARCHIVE_OK) {
932 			r = get_entry_symlink(a, entry_main, &linkpath,
933 			    &linkpath_length, NULL);
934 			if (r == ARCHIVE_FATAL) {
935 				archive_entry_free(entry_main);
936 				return (r);
937 			}
938 			archive_set_error(&a->archive,
939 			    ARCHIVE_ERRNO_FILE_FORMAT,
940 			    "Can't translate linkname '%s' to %s", linkpath,
941 			    archive_string_conversion_charset_name(sconv));
942 			ret = ARCHIVE_WARN;
943 			sconv = NULL;
944 		}
945 	}
946 
947 	/* If any string conversions failed, get all attributes
948 	 * in binary-mode. */
949 	if (sconv == NULL && !pax->opt_binary) {
950 		if (hardlink != NULL) {
951 			r = get_entry_hardlink(a, entry_main, &hardlink,
952 			    &hardlink_length, NULL);
953 			if (r == ARCHIVE_FATAL) {
954 				archive_entry_free(entry_main);
955 				return (r);
956 			}
957 			linkpath = hardlink;
958 			linkpath_length = hardlink_length;
959 		}
960 		r = get_entry_pathname(a, entry_main, &path,
961 		    &path_length, NULL);
962 		if (r == ARCHIVE_FATAL) {
963 			archive_entry_free(entry_main);
964 			return (r);
965 		}
966 		r = get_entry_uname(a, entry_main, &uname, &uname_length, NULL);
967 		if (r == ARCHIVE_FATAL) {
968 			archive_entry_free(entry_main);
969 			return (r);
970 		}
971 		r = get_entry_gname(a, entry_main, &gname, &gname_length, NULL);
972 		if (r == ARCHIVE_FATAL) {
973 			archive_entry_free(entry_main);
974 			return (r);
975 		}
976 	}
977 
978 	/* Store the header encoding first, to be nice to readers. */
979 	if (sconv == NULL)
980 		add_pax_attr(&(pax->pax_header), "hdrcharset", "BINARY");
981 
982 
983 	/*
984 	 * If name is too long, or has non-ASCII characters, add
985 	 * 'path' to pax extended attrs.  (Note that an unconvertible
986 	 * name must have non-ASCII characters.)
987 	 */
988 	if (has_non_ASCII(path)) {
989 		/* We have non-ASCII characters. */
990 		add_pax_attr(&(pax->pax_header), "path", path);
991 		archive_entry_set_pathname(entry_main,
992 		    build_ustar_entry_name(ustar_entry_name,
993 			path, path_length, NULL));
994 		need_extension = 1;
995 	} else {
996 		/* We have an all-ASCII path; we'd like to just store
997 		 * it in the ustar header if it will fit.  Yes, this
998 		 * duplicates some of the logic in
999 		 * archive_write_set_format_ustar.c
1000 		 */
1001 		if (path_length <= 100) {
1002 			/* Fits in the old 100-char tar name field. */
1003 		} else {
1004 			/* Find largest suffix that will fit. */
1005 			/* Note: strlen() > 100, so strlen() - 100 - 1 >= 0 */
1006 			suffix = strchr(path + path_length - 100 - 1, '/');
1007 			/* Don't attempt an empty prefix. */
1008 			if (suffix == path)
1009 				suffix = strchr(suffix + 1, '/');
1010 			/* We can put it in the ustar header if it's
1011 			 * all ASCII and it's either <= 100 characters
1012 			 * or can be split at a '/' into a prefix <=
1013 			 * 155 chars and a suffix <= 100 chars.  (Note
1014 			 * the strchr() above will return NULL exactly
1015 			 * when the path can't be split.)
1016 			 */
1017 			if (suffix == NULL       /* Suffix > 100 chars. */
1018 			    || suffix[1] == '\0'    /* empty suffix */
1019 			    || suffix - path > 155)  /* Prefix > 155 chars */
1020 			{
1021 				add_pax_attr(&(pax->pax_header), "path", path);
1022 				archive_entry_set_pathname(entry_main,
1023 				    build_ustar_entry_name(ustar_entry_name,
1024 					path, path_length, NULL));
1025 				need_extension = 1;
1026 			}
1027 		}
1028 	}
1029 
1030 	if (linkpath != NULL) {
1031 		/* If link name is too long or has non-ASCII characters, add
1032 		 * 'linkpath' to pax extended attrs. */
1033 		if (linkpath_length > 100 || has_non_ASCII(linkpath)) {
1034 			add_pax_attr(&(pax->pax_header), "linkpath", linkpath);
1035 			if (linkpath_length > 100) {
1036 				if (hardlink != NULL)
1037 					archive_entry_set_hardlink(entry_main,
1038 					    "././@LongHardLink");
1039 				else
1040 					archive_entry_set_symlink(entry_main,
1041 					    "././@LongSymLink");
1042 			}
1043 			else {
1044 				/* Otherwise, has non-ASCII characters; update the paths to
1045 				 * however they got decoded above */
1046 				if (hardlink != NULL)
1047 					archive_entry_set_hardlink(entry_main, linkpath);
1048 				else
1049 					archive_entry_set_symlink(entry_main, linkpath);
1050 			}
1051 			need_extension = 1;
1052 		}
1053 	}
1054 	/* Save a pathname since it will be renamed if `entry_main` has
1055 	 * sparse blocks. */
1056 	archive_string_init(&entry_name);
1057 	archive_strcpy(&entry_name, archive_entry_pathname(entry_main));
1058 
1059 	/* If file size is too large, we need pax extended attrs. */
1060 	if (archive_entry_size(entry_main) >= (((int64_t)1) << 33)) {
1061 		need_extension = 1;
1062 	}
1063 
1064 	/* If numeric GID is too large, add 'gid' to pax extended attrs. */
1065 	if ((unsigned int)archive_entry_gid(entry_main) >= (1 << 18)) {
1066 		add_pax_attr_int(&(pax->pax_header), "gid",
1067 		    archive_entry_gid(entry_main));
1068 		need_extension = 1;
1069 	}
1070 
1071 	/* If group name is too large or has non-ASCII characters, add
1072 	 * 'gname' to pax extended attrs. */
1073 	if (gname != NULL) {
1074 		if (gname_length > 31 || has_non_ASCII(gname)) {
1075 			add_pax_attr(&(pax->pax_header), "gname", gname);
1076 			need_extension = 1;
1077 		}
1078 	}
1079 
1080 	/* If numeric UID is too large, add 'uid' to pax extended attrs. */
1081 	if ((unsigned int)archive_entry_uid(entry_main) >= (1 << 18)) {
1082 		add_pax_attr_int(&(pax->pax_header), "uid",
1083 		    archive_entry_uid(entry_main));
1084 		need_extension = 1;
1085 	}
1086 
1087 	/* Add 'uname' to pax extended attrs if necessary. */
1088 	if (uname != NULL) {
1089 		if (uname_length > 31 || has_non_ASCII(uname)) {
1090 			add_pax_attr(&(pax->pax_header), "uname", uname);
1091 			need_extension = 1;
1092 		}
1093 	}
1094 
1095 	/*
1096 	 * POSIX/SUSv3 doesn't provide a standard key for large device
1097 	 * numbers.  I use the same keys here that Joerg Schilling
1098 	 * used for 'star.'  (Which, somewhat confusingly, are called
1099 	 * "devXXX" even though they code "rdev" values.)  No doubt,
1100 	 * other implementations use other keys.  Note that there's no
1101 	 * reason we can't write the same information into a number of
1102 	 * different keys.
1103 	 *
1104 	 * Of course, this is only needed for block or char device entries.
1105 	 */
1106 	if (archive_entry_filetype(entry_main) == AE_IFBLK
1107 	    || archive_entry_filetype(entry_main) == AE_IFCHR) {
1108 		/*
1109 		 * If rdevmajor is too large, add 'SCHILY.devmajor' to
1110 		 * extended attributes.
1111 		 */
1112 		int rdevmajor, rdevminor;
1113 		rdevmajor = archive_entry_rdevmajor(entry_main);
1114 		rdevminor = archive_entry_rdevminor(entry_main);
1115 		if (rdevmajor >= (1 << 18)) {
1116 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devmajor",
1117 			    rdevmajor);
1118 			/*
1119 			 * Non-strict formatting below means we don't
1120 			 * have to truncate here.  Not truncating improves
1121 			 * the chance that some more modern tar archivers
1122 			 * (such as GNU tar 1.13) can restore the full
1123 			 * value even if they don't understand the pax
1124 			 * extended attributes.  See my rant below about
1125 			 * file size fields for additional details.
1126 			 */
1127 			/* archive_entry_set_rdevmajor(entry_main,
1128 			   rdevmajor & ((1 << 18) - 1)); */
1129 			need_extension = 1;
1130 		}
1131 
1132 		/*
1133 		 * If devminor is too large, add 'SCHILY.devminor' to
1134 		 * extended attributes.
1135 		 */
1136 		if (rdevminor >= (1 << 18)) {
1137 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devminor",
1138 			    rdevminor);
1139 			/* Truncation is not necessary here, either. */
1140 			/* archive_entry_set_rdevminor(entry_main,
1141 			   rdevminor & ((1 << 18) - 1)); */
1142 			need_extension = 1;
1143 		}
1144 	}
1145 
1146 	/*
1147 	 * Yes, this check is duplicated just below; this helps to
1148 	 * avoid writing an mtime attribute just to handle a
1149 	 * high-resolution timestamp in "restricted pax" mode.
1150 	 */
1151 	if (!need_extension &&
1152 	    ((archive_entry_mtime(entry_main) < 0)
1153 		|| (archive_entry_mtime(entry_main) >= ustar_max_mtime)))
1154 		need_extension = 1;
1155 
1156 	/* I use a star-compatible file flag attribute. */
1157 	p = archive_entry_fflags_text(entry_main);
1158 	if (!need_extension && p != NULL  &&  *p != '\0')
1159 		need_extension = 1;
1160 
1161 	/* If there are extended attributes, we need an extension */
1162 	if (!need_extension && archive_entry_xattr_count(entry_original) > 0)
1163 		need_extension = 1;
1164 
1165 	/* If there are sparse info, we need an extension */
1166 	if (!need_extension && sparse_count > 0)
1167 		need_extension = 1;
1168 
1169 	acl_types = archive_entry_acl_types(entry_original);
1170 
1171 	/* If there are any ACL entries, we need an extension */
1172 	if (!need_extension && acl_types != 0)
1173 		need_extension = 1;
1174 
1175 	/* If the symlink type is defined, we need an extension */
1176 	if (!need_extension && archive_entry_symlink_type(entry_main) > 0)
1177 		need_extension = 1;
1178 
1179 	/*
1180 	 * Libarchive used to include these in extended headers for
1181 	 * restricted pax format, but that confused people who
1182 	 * expected ustar-like time semantics.  So now we only include
1183 	 * them in full pax format.
1184 	 */
1185 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED) {
1186 		if (archive_entry_ctime(entry_main) != 0  ||
1187 		    archive_entry_ctime_nsec(entry_main) != 0)
1188 			add_pax_attr_time(&(pax->pax_header), "ctime",
1189 			    archive_entry_ctime(entry_main),
1190 			    archive_entry_ctime_nsec(entry_main));
1191 
1192 		if (archive_entry_atime(entry_main) != 0 ||
1193 		    archive_entry_atime_nsec(entry_main) != 0)
1194 			add_pax_attr_time(&(pax->pax_header), "atime",
1195 			    archive_entry_atime(entry_main),
1196 			    archive_entry_atime_nsec(entry_main));
1197 
1198 		/* Store birth/creationtime only if it's earlier than mtime */
1199 		if (archive_entry_birthtime_is_set(entry_main) &&
1200 		    archive_entry_birthtime(entry_main)
1201 		    < archive_entry_mtime(entry_main))
1202 			add_pax_attr_time(&(pax->pax_header),
1203 			    "LIBARCHIVE.creationtime",
1204 			    archive_entry_birthtime(entry_main),
1205 			    archive_entry_birthtime_nsec(entry_main));
1206 	}
1207 
1208 	/*
1209 	 * The following items are handled differently in "pax
1210 	 * restricted" format.  In particular, in "pax restricted"
1211 	 * format they won't be added unless need_extension is
1212 	 * already set (we're already generating an extended header, so
1213 	 * may as well include these).
1214 	 */
1215 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED ||
1216 	    need_extension) {
1217 		if (archive_entry_mtime(entry_main) < 0  ||
1218 		    archive_entry_mtime(entry_main) >= ustar_max_mtime  ||
1219 		    archive_entry_mtime_nsec(entry_main) != 0)
1220 			add_pax_attr_time(&(pax->pax_header), "mtime",
1221 			    archive_entry_mtime(entry_main),
1222 			    archive_entry_mtime_nsec(entry_main));
1223 
1224 		/* I use a star-compatible file flag attribute. */
1225 		p = archive_entry_fflags_text(entry_main);
1226 		if (p != NULL  &&  *p != '\0')
1227 			add_pax_attr(&(pax->pax_header), "SCHILY.fflags", p);
1228 
1229 		/* I use star-compatible ACL attributes. */
1230 		if ((acl_types & ARCHIVE_ENTRY_ACL_TYPE_NFS4) != 0) {
1231 			ret = add_pax_acl(a, entry_original, pax,
1232 			    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID |
1233 			    ARCHIVE_ENTRY_ACL_STYLE_SEPARATOR_COMMA |
1234 			    ARCHIVE_ENTRY_ACL_STYLE_COMPACT);
1235 			if (ret == ARCHIVE_FATAL) {
1236 				archive_entry_free(entry_main);
1237 				archive_string_free(&entry_name);
1238 				return (ARCHIVE_FATAL);
1239 			}
1240 		}
1241 		if (acl_types & ARCHIVE_ENTRY_ACL_TYPE_ACCESS) {
1242 			ret = add_pax_acl(a, entry_original, pax,
1243 			    ARCHIVE_ENTRY_ACL_TYPE_ACCESS |
1244 			    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID |
1245 			    ARCHIVE_ENTRY_ACL_STYLE_SEPARATOR_COMMA);
1246 			if (ret == ARCHIVE_FATAL) {
1247 				archive_entry_free(entry_main);
1248 				archive_string_free(&entry_name);
1249 				return (ARCHIVE_FATAL);
1250 			}
1251 		}
1252 		if (acl_types & ARCHIVE_ENTRY_ACL_TYPE_DEFAULT) {
1253 			ret = add_pax_acl(a, entry_original, pax,
1254 			    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT |
1255 			    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID |
1256 			    ARCHIVE_ENTRY_ACL_STYLE_SEPARATOR_COMMA);
1257 			if (ret == ARCHIVE_FATAL) {
1258 				archive_entry_free(entry_main);
1259 				archive_string_free(&entry_name);
1260 				return (ARCHIVE_FATAL);
1261 			}
1262 		}
1263 
1264 		/* We use GNU-tar-compatible sparse attributes. */
1265 		if (sparse_count > 0) {
1266 			int64_t soffset, slength;
1267 
1268 			add_pax_attr_int(&(pax->pax_header),
1269 			    "GNU.sparse.major", 1);
1270 			add_pax_attr_int(&(pax->pax_header),
1271 			    "GNU.sparse.minor", 0);
1272 			/*
1273 			 * Make sure to store the original path, since
1274 			 * truncation to ustar limit happened already.
1275 			 */
1276 			add_pax_attr(&(pax->pax_header),
1277 			    "GNU.sparse.name", path);
1278 			add_pax_attr_int(&(pax->pax_header),
1279 			    "GNU.sparse.realsize",
1280 			    archive_entry_size(entry_main));
1281 
1282 			/* Rename the file name which will be used for
1283 			 * ustar header to a special name, which GNU
1284 			 * PAX Format 1.0 requires */
1285 			archive_entry_set_pathname(entry_main,
1286 			    build_gnu_sparse_name(gnu_sparse_name,
1287 			        entry_name.s));
1288 
1289 			/*
1290 			 * - Make a sparse map, which will precede a file data.
1291 			 * - Get the total size of available data of sparse.
1292 			 */
1293 			archive_string_sprintf(&(pax->sparse_map), "%d\n",
1294 			    sparse_count);
1295 			while (archive_entry_sparse_next(entry_main,
1296 			    &soffset, &slength) == ARCHIVE_OK) {
1297 				archive_string_sprintf(&(pax->sparse_map),
1298 				    "%jd\n%jd\n",
1299 				    (intmax_t)soffset,
1300 				    (intmax_t)slength);
1301 				sparse_total += slength;
1302 				if (sparse_list_add(pax, soffset, slength)
1303 				    != ARCHIVE_OK) {
1304 					archive_set_error(&a->archive,
1305 					    ENOMEM,
1306 					    "Can't allocate memory");
1307 					archive_entry_free(entry_main);
1308 					archive_string_free(&entry_name);
1309 					return (ARCHIVE_FATAL);
1310 				}
1311 			}
1312 		}
1313 
1314 		/* Store extended attributes */
1315 		if (archive_write_pax_header_xattrs(a, pax, entry_original)
1316 		    == ARCHIVE_FATAL) {
1317 			archive_entry_free(entry_main);
1318 			archive_string_free(&entry_name);
1319 			return (ARCHIVE_FATAL);
1320 		}
1321 
1322 		/* Store extended symlink information */
1323 		if (archive_entry_symlink_type(entry_main) ==
1324 		    AE_SYMLINK_TYPE_FILE) {
1325 			add_pax_attr(&(pax->pax_header),
1326 			    "LIBARCHIVE.symlinktype", "file");
1327 		} else if (archive_entry_symlink_type(entry_main) ==
1328 		    AE_SYMLINK_TYPE_DIRECTORY) {
1329 			add_pax_attr(&(pax->pax_header),
1330 			    "LIBARCHIVE.symlinktype", "dir");
1331 		}
1332 	}
1333 
1334 	/* Only regular files have data. */
1335 	if (archive_entry_filetype(entry_main) != AE_IFREG)
1336 		archive_entry_set_size(entry_main, 0);
1337 
1338 	/*
1339 	 * Pax-restricted does not store data for hardlinks, in order
1340 	 * to improve compatibility with ustar.
1341 	 */
1342 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE &&
1343 	    hardlink != NULL)
1344 		archive_entry_set_size(entry_main, 0);
1345 
1346 	/*
1347 	 * XXX Full pax interchange format does permit a hardlink
1348 	 * entry to have data associated with it.  I'm not supporting
1349 	 * that here because the client expects me to tell them whether
1350 	 * or not this format expects data for hardlinks.  If I
1351 	 * don't check here, then every pax archive will end up with
1352 	 * duplicated data for hardlinks.  Someday, there may be
1353 	 * need to select this behavior, in which case the following
1354 	 * will need to be revisited. XXX
1355 	 */
1356 	if (hardlink != NULL)
1357 		archive_entry_set_size(entry_main, 0);
1358 
1359 	/* Save a real file size. */
1360 	real_size = archive_entry_size(entry_main);
1361 	/*
1362 	 * Overwrite a file size by the total size of sparse blocks and
1363 	 * the size of sparse map info. That file size is the length of
1364 	 * the data, which we will exactly store into an archive file.
1365 	 */
1366 	if (archive_strlen(&(pax->sparse_map))) {
1367 		size_t mapsize = archive_strlen(&(pax->sparse_map));
1368 		pax->sparse_map_padding = 0x1ff & (-(ssize_t)mapsize);
1369 		archive_entry_set_size(entry_main,
1370 		    mapsize + pax->sparse_map_padding + sparse_total);
1371 	}
1372 
1373 	/* If file size is too large, add 'size' to pax extended attrs. */
1374 	if (archive_entry_size(entry_main) >= (((int64_t)1) << 33)) {
1375 		add_pax_attr_int(&(pax->pax_header), "size",
1376 		    archive_entry_size(entry_main));
1377 	}
1378 
1379 	/* Format 'ustar' header for main entry.
1380 	 *
1381 	 * The trouble with file size: If the reader can't understand
1382 	 * the file size, they may not be able to locate the next
1383 	 * entry and the rest of the archive is toast.  Pax-compliant
1384 	 * readers are supposed to ignore the file size in the main
1385 	 * header, so the question becomes how to maximize portability
1386 	 * for readers that don't support pax attribute extensions.
1387 	 * For maximum compatibility, I permit numeric extensions in
1388 	 * the main header so that the file size stored will always be
1389 	 * correct, even if it's in a format that only some
1390 	 * implementations understand.  The technique used here is:
1391 	 *
1392 	 *  a) If possible, follow the standard exactly.  This handles
1393 	 *  files up to 8 gigabytes minus 1.
1394 	 *
1395 	 *  b) If that fails, try octal but omit the field terminator.
1396 	 *  That handles files up to 64 gigabytes minus 1.
1397 	 *
1398 	 *  c) Otherwise, use base-256 extensions.  That handles files
1399 	 *  up to 2^63 in this implementation, with the potential to
1400 	 *  go up to 2^94.  That should hold us for a while. ;-)
1401 	 *
1402 	 * The non-strict formatter uses similar logic for other
1403 	 * numeric fields, though they're less critical.
1404 	 */
1405 	if (__archive_write_format_header_ustar(a, ustarbuff, entry_main, -1, 0,
1406 	    NULL) == ARCHIVE_FATAL) {
1407 		archive_entry_free(entry_main);
1408 		archive_string_free(&entry_name);
1409 		return (ARCHIVE_FATAL);
1410 	}
1411 
1412 	/* If we built any extended attributes, write that entry first. */
1413 	if (archive_strlen(&(pax->pax_header)) > 0) {
1414 		struct archive_entry *pax_attr_entry;
1415 		time_t s;
1416 		int64_t uid, gid;
1417 		int mode;
1418 
1419 		pax_attr_entry = archive_entry_new2(&a->archive);
1420 		p = entry_name.s;
1421 		archive_entry_set_pathname(pax_attr_entry,
1422 		    build_pax_attribute_name(pax_entry_name, p));
1423 		archive_entry_set_size(pax_attr_entry,
1424 		    archive_strlen(&(pax->pax_header)));
1425 		/* Copy uid/gid (but clip to ustar limits). */
1426 		uid = archive_entry_uid(entry_main);
1427 		if (uid >= 1 << 18)
1428 			uid = (1 << 18) - 1;
1429 		archive_entry_set_uid(pax_attr_entry, uid);
1430 		gid = archive_entry_gid(entry_main);
1431 		if (gid >= 1 << 18)
1432 			gid = (1 << 18) - 1;
1433 		archive_entry_set_gid(pax_attr_entry, gid);
1434 		/* Copy mode over (but not setuid/setgid bits) */
1435 		mode = archive_entry_mode(entry_main);
1436 #ifdef S_ISUID
1437 		mode &= ~S_ISUID;
1438 #endif
1439 #ifdef S_ISGID
1440 		mode &= ~S_ISGID;
1441 #endif
1442 #ifdef S_ISVTX
1443 		mode &= ~S_ISVTX;
1444 #endif
1445 		archive_entry_set_mode(pax_attr_entry, mode);
1446 
1447 		/* Copy uname/gname. */
1448 		archive_entry_set_uname(pax_attr_entry,
1449 		    archive_entry_uname(entry_main));
1450 		archive_entry_set_gname(pax_attr_entry,
1451 		    archive_entry_gname(entry_main));
1452 
1453 		/* Copy mtime, but clip to ustar limits. */
1454 		s = archive_entry_mtime(entry_main);
1455 		if (s < 0) { s = 0; }
1456 		if (s > ustar_max_mtime) { s = ustar_max_mtime; }
1457 		archive_entry_set_mtime(pax_attr_entry, s, 0);
1458 
1459 		/* Standard ustar doesn't support atime. */
1460 		archive_entry_set_atime(pax_attr_entry, 0, 0);
1461 
1462 		/* Standard ustar doesn't support ctime. */
1463 		archive_entry_set_ctime(pax_attr_entry, 0, 0);
1464 
1465 		r = __archive_write_format_header_ustar(a, paxbuff,
1466 		    pax_attr_entry, 'x', 1, NULL);
1467 
1468 		archive_entry_free(pax_attr_entry);
1469 
1470 		/* Note that the 'x' header shouldn't ever fail to format */
1471 		if (r < ARCHIVE_WARN) {
1472 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1473 			    "archive_write_pax_header: "
1474 			    "'x' header failed?!  This can't happen.\n");
1475 			archive_entry_free(entry_main);
1476 			archive_string_free(&entry_name);
1477 			return (ARCHIVE_FATAL);
1478 		} else if (r < ret)
1479 			ret = r;
1480 		r = __archive_write_output(a, paxbuff, 512);
1481 		if (r != ARCHIVE_OK) {
1482 			sparse_list_clear(pax);
1483 			pax->entry_bytes_remaining = 0;
1484 			pax->entry_padding = 0;
1485 			archive_entry_free(entry_main);
1486 			archive_string_free(&entry_name);
1487 			return (ARCHIVE_FATAL);
1488 		}
1489 
1490 		pax->entry_bytes_remaining = archive_strlen(&(pax->pax_header));
1491 		pax->entry_padding =
1492 		    0x1ff & (-(int64_t)pax->entry_bytes_remaining);
1493 
1494 		r = __archive_write_output(a, pax->pax_header.s,
1495 		    archive_strlen(&(pax->pax_header)));
1496 		if (r != ARCHIVE_OK) {
1497 			/* If a write fails, we're pretty much toast. */
1498 			archive_entry_free(entry_main);
1499 			archive_string_free(&entry_name);
1500 			return (ARCHIVE_FATAL);
1501 		}
1502 		/* Pad out the end of the entry. */
1503 		r = __archive_write_nulls(a, (size_t)pax->entry_padding);
1504 		if (r != ARCHIVE_OK) {
1505 			/* If a write fails, we're pretty much toast. */
1506 			archive_entry_free(entry_main);
1507 			archive_string_free(&entry_name);
1508 			return (ARCHIVE_FATAL);
1509 		}
1510 		pax->entry_bytes_remaining = pax->entry_padding = 0;
1511 	}
1512 
1513 	/* Write the header for main entry. */
1514 	r = __archive_write_output(a, ustarbuff, 512);
1515 	if (r != ARCHIVE_OK) {
1516 		archive_entry_free(entry_main);
1517 		archive_string_free(&entry_name);
1518 		return (r);
1519 	}
1520 
1521 	/*
1522 	 * Inform the client of the on-disk size we're using, so
1523 	 * they can avoid unnecessarily writing a body for something
1524 	 * that we're just going to ignore.
1525 	 */
1526 	archive_entry_set_size(entry_original, real_size);
1527 	if (pax->sparse_list == NULL && real_size > 0) {
1528 		/* This is not a sparse file but we handle its data as
1529 		 * a sparse block. */
1530 		sparse_list_add(pax, 0, real_size);
1531 		sparse_total = real_size;
1532 	}
1533 	pax->entry_padding = 0x1ff & (-(int64_t)sparse_total);
1534 	archive_entry_free(entry_main);
1535 	archive_string_free(&entry_name);
1536 
1537 	return (ret);
1538 }
1539 
1540 /*
1541  * We need a valid name for the regular 'ustar' entry.  This routine
1542  * tries to hack something more-or-less reasonable.
1543  *
1544  * The approach here tries to preserve leading dir names.  We do so by
1545  * working with four sections:
1546  *   1) "prefix" directory names,
1547  *   2) "suffix" directory names,
1548  *   3) inserted dir name (optional),
1549  *   4) filename.
1550  *
1551  * These sections must satisfy the following requirements:
1552  *   * Parts 1 & 2 together form an initial portion of the dir name.
1553  *   * Part 3 is specified by the caller.  (It should not contain a leading
1554  *     or trailing '/'.)
1555  *   * Part 4 forms an initial portion of the base filename.
1556  *   * The filename must be <= 99 chars to fit the ustar 'name' field.
1557  *   * Parts 2, 3, 4 together must be <= 99 chars to fit the ustar 'name' fld.
1558  *   * Part 1 must be <= 155 chars to fit the ustar 'prefix' field.
1559  *   * If the original name ends in a '/', the new name must also end in a '/'
1560  *   * Trailing '/.' sequences may be stripped.
1561  *
1562  * Note: Recall that the ustar format does not store the '/' separating
1563  * parts 1 & 2, but does store the '/' separating parts 2 & 3.
1564  */
1565 static char *
1566 build_ustar_entry_name(char *dest, const char *src, size_t src_length,
1567     const char *insert)
1568 {
1569 	const char *prefix, *prefix_end;
1570 	const char *suffix, *suffix_end;
1571 	const char *filename, *filename_end;
1572 	char *p;
1573 	int need_slash = 0; /* Was there a trailing slash? */
1574 	size_t suffix_length = 99;
1575 	size_t insert_length;
1576 
1577 	/* Length of additional dir element to be added. */
1578 	if (insert == NULL)
1579 		insert_length = 0;
1580 	else
1581 		/* +2 here allows for '/' before and after the insert. */
1582 		insert_length = strlen(insert) + 2;
1583 
1584 	/* Step 0: Quick bailout in a common case. */
1585 	if (src_length < 100 && insert == NULL) {
1586 		strncpy(dest, src, src_length);
1587 		dest[src_length] = '\0';
1588 		return (dest);
1589 	}
1590 
1591 	/* Step 1: Locate filename and enforce the length restriction. */
1592 	filename_end = src + src_length;
1593 	/* Remove trailing '/' chars and '/.' pairs. */
1594 	for (;;) {
1595 		if (filename_end > src && filename_end[-1] == '/') {
1596 			filename_end --;
1597 			need_slash = 1; /* Remember to restore trailing '/'. */
1598 			continue;
1599 		}
1600 		if (filename_end > src + 1 && filename_end[-1] == '.'
1601 		    && filename_end[-2] == '/') {
1602 			filename_end -= 2;
1603 			need_slash = 1; /* "foo/." will become "foo/" */
1604 			continue;
1605 		}
1606 		break;
1607 	}
1608 	if (need_slash)
1609 		suffix_length--;
1610 	/* Find start of filename. */
1611 	filename = filename_end - 1;
1612 	while ((filename > src) && (*filename != '/'))
1613 		filename --;
1614 	if ((*filename == '/') && (filename < filename_end - 1))
1615 		filename ++;
1616 	/* Adjust filename_end so that filename + insert fits in 99 chars. */
1617 	suffix_length -= insert_length;
1618 	if (filename_end > filename + suffix_length)
1619 		filename_end = filename + suffix_length;
1620 	/* Calculate max size for "suffix" section (#3 above). */
1621 	suffix_length -= filename_end - filename;
1622 
1623 	/* Step 2: Locate the "prefix" section of the dirname, including
1624 	 * trailing '/'. */
1625 	prefix = src;
1626 	prefix_end = prefix + 155;
1627 	if (prefix_end > filename)
1628 		prefix_end = filename;
1629 	while (prefix_end > prefix && *prefix_end != '/')
1630 		prefix_end--;
1631 	if ((prefix_end < filename) && (*prefix_end == '/'))
1632 		prefix_end++;
1633 
1634 	/* Step 3: Locate the "suffix" section of the dirname,
1635 	 * including trailing '/'. */
1636 	suffix = prefix_end;
1637 	suffix_end = suffix + suffix_length; /* Enforce limit. */
1638 	if (suffix_end > filename)
1639 		suffix_end = filename;
1640 	if (suffix_end < suffix)
1641 		suffix_end = suffix;
1642 	while (suffix_end > suffix && *suffix_end != '/')
1643 		suffix_end--;
1644 	if ((suffix_end < filename) && (*suffix_end == '/'))
1645 		suffix_end++;
1646 
1647 	/* Step 4: Build the new name. */
1648 	/* The OpenBSD strlcpy function is safer, but less portable. */
1649 	/* Rather than maintain two versions, just use the strncpy version. */
1650 	p = dest;
1651 	if (prefix_end > prefix) {
1652 		strncpy(p, prefix, prefix_end - prefix);
1653 		p += prefix_end - prefix;
1654 	}
1655 	if (suffix_end > suffix) {
1656 		strncpy(p, suffix, suffix_end - suffix);
1657 		p += suffix_end - suffix;
1658 	}
1659 	if (insert != NULL) {
1660 		/* Note: assume insert does not have leading or trailing '/' */
1661 		strcpy(p, insert);
1662 		p += strlen(insert);
1663 		*p++ = '/';
1664 	}
1665 	strncpy(p, filename, filename_end - filename);
1666 	p += filename_end - filename;
1667 	if (need_slash)
1668 		*p++ = '/';
1669 	*p = '\0';
1670 
1671 	return (dest);
1672 }
1673 
1674 /*
1675  * The ustar header for the pax extended attributes must have a
1676  * reasonable name:  SUSv3 requires 'dirname'/PaxHeader.'pid'/'filename'
1677  * where 'pid' is the PID of the archiving process.  Unfortunately,
1678  * that makes testing a pain since the output varies for each run,
1679  * so I'm sticking with the simpler 'dirname'/PaxHeader/'filename'
1680  * for now.  (Someday, I'll make this settable.  Then I can use the
1681  * SUS recommendation as default and test harnesses can override it
1682  * to get predictable results.)
1683  *
1684  * Joerg Schilling has argued that this is unnecessary because, in
1685  * practice, if the pax extended attributes get extracted as regular
1686  * files, no one is going to bother reading those attributes to
1687  * manually restore them.  Based on this, 'star' uses
1688  * /tmp/PaxHeader/'basename' as the ustar header name.  This is a
1689  * tempting argument, in part because it's simpler than the SUSv3
1690  * recommendation, but I'm not entirely convinced.  I'm also
1691  * uncomfortable with the fact that "/tmp" is a Unix-ism.
1692  *
1693  * The following routine leverages build_ustar_entry_name() above and
1694  * so is simpler than you might think.  It just needs to provide the
1695  * additional path element and handle a few pathological cases).
1696  */
1697 static char *
1698 build_pax_attribute_name(char *dest, const char *src)
1699 {
1700 	char buff[64];
1701 	const char *p;
1702 
1703 	/* Handle the null filename case. */
1704 	if (src == NULL || *src == '\0') {
1705 		strcpy(dest, "PaxHeader/blank");
1706 		return (dest);
1707 	}
1708 
1709 	/* Prune final '/' and other unwanted final elements. */
1710 	p = src + strlen(src);
1711 	for (;;) {
1712 		/* Ends in "/", remove the '/' */
1713 		if (p > src && p[-1] == '/') {
1714 			--p;
1715 			continue;
1716 		}
1717 		/* Ends in "/.", remove the '.' */
1718 		if (p > src + 1 && p[-1] == '.'
1719 		    && p[-2] == '/') {
1720 			--p;
1721 			continue;
1722 		}
1723 		break;
1724 	}
1725 
1726 	/* Pathological case: After above, there was nothing left.
1727 	 * This includes "/." "/./." "/.//./." etc. */
1728 	if (p == src) {
1729 		strcpy(dest, "/PaxHeader/rootdir");
1730 		return (dest);
1731 	}
1732 
1733 	/* Convert unadorned "." into a suitable filename. */
1734 	if (*src == '.' && p == src + 1) {
1735 		strcpy(dest, "PaxHeader/currentdir");
1736 		return (dest);
1737 	}
1738 
1739 	/*
1740 	 * TODO: Push this string into the 'pax' structure to avoid
1741 	 * recomputing it every time.  That will also open the door
1742 	 * to having clients override it.
1743 	 */
1744 #if HAVE_GETPID && 0  /* Disable this for now; see above comment. */
1745 	snprintf(buff, sizeof(buff), "PaxHeader.%d", getpid());
1746 #else
1747 	/* If the platform can't fetch the pid, don't include it. */
1748 	strcpy(buff, "PaxHeader");
1749 #endif
1750 	/* General case: build a ustar-compatible name adding
1751 	 * "/PaxHeader/". */
1752 	build_ustar_entry_name(dest, src, p - src, buff);
1753 
1754 	return (dest);
1755 }
1756 
1757 /*
1758  * GNU PAX Format 1.0 requires the special name, which pattern is:
1759  * <dir>/GNUSparseFile.<pid>/<original file name>
1760  *
1761  * Since reproducible archives are more important, use 0 as pid.
1762  *
1763  * This function is used for only Sparse file, a file type of which
1764  * is regular file.
1765  */
1766 static char *
1767 build_gnu_sparse_name(char *dest, const char *src)
1768 {
1769 	const char *p;
1770 
1771 	/* Handle the null filename case. */
1772 	if (src == NULL || *src == '\0') {
1773 		strcpy(dest, "GNUSparseFile/blank");
1774 		return (dest);
1775 	}
1776 
1777 	/* Prune final '/' and other unwanted final elements. */
1778 	p = src + strlen(src);
1779 	for (;;) {
1780 		/* Ends in "/", remove the '/' */
1781 		if (p > src && p[-1] == '/') {
1782 			--p;
1783 			continue;
1784 		}
1785 		/* Ends in "/.", remove the '.' */
1786 		if (p > src + 1 && p[-1] == '.'
1787 		    && p[-2] == '/') {
1788 			--p;
1789 			continue;
1790 		}
1791 		break;
1792 	}
1793 
1794 	/* General case: build a ustar-compatible name adding
1795 	 * "/GNUSparseFile/". */
1796 	build_ustar_entry_name(dest, src, p - src, "GNUSparseFile.0");
1797 
1798 	return (dest);
1799 }
1800 
1801 /* Write two null blocks for the end of archive */
1802 static int
1803 archive_write_pax_close(struct archive_write *a)
1804 {
1805 	return (__archive_write_nulls(a, 512 * 2));
1806 }
1807 
1808 static int
1809 archive_write_pax_free(struct archive_write *a)
1810 {
1811 	struct pax *pax;
1812 
1813 	pax = (struct pax *)a->format_data;
1814 	if (pax == NULL)
1815 		return (ARCHIVE_OK);
1816 
1817 	archive_string_free(&pax->pax_header);
1818 	archive_string_free(&pax->sparse_map);
1819 	archive_string_free(&pax->l_url_encoded_name);
1820 	sparse_list_clear(pax);
1821 	free(pax);
1822 	a->format_data = NULL;
1823 	return (ARCHIVE_OK);
1824 }
1825 
1826 static int
1827 archive_write_pax_finish_entry(struct archive_write *a)
1828 {
1829 	struct pax *pax;
1830 	uint64_t remaining;
1831 	int ret;
1832 
1833 	pax = (struct pax *)a->format_data;
1834 	remaining = pax->entry_bytes_remaining;
1835 	if (remaining == 0) {
1836 		while (pax->sparse_list) {
1837 			struct sparse_block *sb;
1838 			if (!pax->sparse_list->is_hole)
1839 				remaining += pax->sparse_list->remaining;
1840 			sb = pax->sparse_list->next;
1841 			free(pax->sparse_list);
1842 			pax->sparse_list = sb;
1843 		}
1844 	}
1845 	ret = __archive_write_nulls(a, (size_t)(remaining + pax->entry_padding));
1846 	pax->entry_bytes_remaining = pax->entry_padding = 0;
1847 	return (ret);
1848 }
1849 
1850 static ssize_t
1851 archive_write_pax_data(struct archive_write *a, const void *buff, size_t s)
1852 {
1853 	struct pax *pax;
1854 	size_t ws;
1855 	size_t total;
1856 	int ret;
1857 
1858 	pax = (struct pax *)a->format_data;
1859 
1860 	/*
1861 	 * According to GNU PAX format 1.0, write a sparse map
1862 	 * before the body.
1863 	 */
1864 	if (archive_strlen(&(pax->sparse_map))) {
1865 		ret = __archive_write_output(a, pax->sparse_map.s,
1866 		    archive_strlen(&(pax->sparse_map)));
1867 		if (ret != ARCHIVE_OK)
1868 			return (ret);
1869 		ret = __archive_write_nulls(a, pax->sparse_map_padding);
1870 		if (ret != ARCHIVE_OK)
1871 			return (ret);
1872 		archive_string_empty(&(pax->sparse_map));
1873 	}
1874 
1875 	total = 0;
1876 	while (total < s) {
1877 		const unsigned char *p;
1878 
1879 		while (pax->sparse_list != NULL &&
1880 		    pax->sparse_list->remaining == 0) {
1881 			struct sparse_block *sb = pax->sparse_list->next;
1882 			free(pax->sparse_list);
1883 			pax->sparse_list = sb;
1884 		}
1885 
1886 		if (pax->sparse_list == NULL)
1887 			return (total);
1888 
1889 		p = ((const unsigned char *)buff) + total;
1890 		ws = s - total;
1891 		if (ws > pax->sparse_list->remaining)
1892 			ws = (size_t)pax->sparse_list->remaining;
1893 
1894 		if (pax->sparse_list->is_hole) {
1895 			/* Current block is hole thus we do not write
1896 			 * the body. */
1897 			pax->sparse_list->remaining -= ws;
1898 			total += ws;
1899 			continue;
1900 		}
1901 
1902 		ret = __archive_write_output(a, p, ws);
1903 		pax->sparse_list->remaining -= ws;
1904 		total += ws;
1905 		if (ret != ARCHIVE_OK)
1906 			return (ret);
1907 	}
1908 	return (total);
1909 }
1910 
1911 static int
1912 has_non_ASCII(const char *_p)
1913 {
1914 	const unsigned char *p = (const unsigned char *)_p;
1915 
1916 	if (p == NULL)
1917 		return (1);
1918 	while (*p != '\0' && *p < 128)
1919 		p++;
1920 	return (*p != '\0');
1921 }
1922 
1923 /*
1924  * Used by extended attribute support; encodes the name
1925  * so that there will be no '=' characters in the result.
1926  */
1927 static char *
1928 url_encode(const char *in)
1929 {
1930 	const char *s;
1931 	char *d;
1932 	size_t out_len = 0;
1933 	char *out;
1934 
1935 	for (s = in; *s != '\0'; s++) {
1936 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=') {
1937 			if (SIZE_MAX - out_len < 4)
1938 				return (NULL);
1939 			out_len += 3;
1940 		} else {
1941 			if (SIZE_MAX - out_len < 2)
1942 				return (NULL);
1943 			out_len++;
1944 		}
1945 	}
1946 
1947 	out = malloc(out_len + 1);
1948 	if (out == NULL)
1949 		return (NULL);
1950 
1951 	for (s = in, d = out; *s != '\0'; s++) {
1952 		/* encode any non-printable ASCII character or '%' or '=' */
1953 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=') {
1954 			/* URL encoding is '%' followed by two hex digits */
1955 			*d++ = '%';
1956 			*d++ = "0123456789ABCDEF"[0x0f & (*s >> 4)];
1957 			*d++ = "0123456789ABCDEF"[0x0f & *s];
1958 		} else {
1959 			*d++ = *s;
1960 		}
1961 	}
1962 	*d = '\0';
1963 	return (out);
1964 }
1965 
1966 /*
1967  * Encode a sequence of bytes into a C string using base-64 encoding.
1968  *
1969  * Returns a null-terminated C string allocated with malloc(); caller
1970  * is responsible for freeing the result.
1971  */
1972 static char *
1973 base64_encode(const char *s, size_t len)
1974 {
1975 	static const char digits[64] =
1976 	    { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O',
1977 	      'P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d',
1978 	      'e','f','g','h','i','j','k','l','m','n','o','p','q','r','s',
1979 	      't','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
1980 	      '8','9','+','/' };
1981 	int v;
1982 	char *d, *out;
1983 
1984 	/* 3 bytes becomes 4 chars, but round up and allow for trailing NUL */
1985 	out = malloc((len * 4 + 2) / 3 + 1);
1986 	if (out == NULL)
1987 		return (NULL);
1988 	d = out;
1989 
1990 	/* Convert each group of 3 bytes into 4 characters. */
1991 	while (len >= 3) {
1992 		v = (((int)s[0] << 16) & 0xff0000)
1993 		    | (((int)s[1] << 8) & 0xff00)
1994 		    | (((int)s[2]) & 0x00ff);
1995 		s += 3;
1996 		len -= 3;
1997 		*d++ = digits[(v >> 18) & 0x3f];
1998 		*d++ = digits[(v >> 12) & 0x3f];
1999 		*d++ = digits[(v >> 6) & 0x3f];
2000 		*d++ = digits[(v) & 0x3f];
2001 	}
2002 	/* Handle final group of 1 byte (2 chars) or 2 bytes (3 chars). */
2003 	switch (len) {
2004 	case 0: break;
2005 	case 1:
2006 		v = (((int)s[0] << 16) & 0xff0000);
2007 		*d++ = digits[(v >> 18) & 0x3f];
2008 		*d++ = digits[(v >> 12) & 0x3f];
2009 		break;
2010 	case 2:
2011 		v = (((int)s[0] << 16) & 0xff0000)
2012 		    | (((int)s[1] << 8) & 0xff00);
2013 		*d++ = digits[(v >> 18) & 0x3f];
2014 		*d++ = digits[(v >> 12) & 0x3f];
2015 		*d++ = digits[(v >> 6) & 0x3f];
2016 		break;
2017 	}
2018 	/* Add trailing NUL character so output is a valid C string. */
2019 	*d = '\0';
2020 	return (out);
2021 }
2022 
2023 static void
2024 sparse_list_clear(struct pax *pax)
2025 {
2026 	while (pax->sparse_list != NULL) {
2027 		struct sparse_block *sb = pax->sparse_list;
2028 		pax->sparse_list = sb->next;
2029 		free(sb);
2030 	}
2031 	pax->sparse_tail = NULL;
2032 }
2033 
2034 static int
2035 _sparse_list_add_block(struct pax *pax, int64_t offset, int64_t length,
2036     int is_hole)
2037 {
2038 	struct sparse_block *sb;
2039 
2040 	sb = malloc(sizeof(*sb));
2041 	if (sb == NULL)
2042 		return (ARCHIVE_FATAL);
2043 	sb->next = NULL;
2044 	sb->is_hole = is_hole;
2045 	sb->offset = offset;
2046 	sb->remaining = length;
2047 	if (pax->sparse_list == NULL || pax->sparse_tail == NULL)
2048 		pax->sparse_list = pax->sparse_tail = sb;
2049 	else {
2050 		pax->sparse_tail->next = sb;
2051 		pax->sparse_tail = sb;
2052 	}
2053 	return (ARCHIVE_OK);
2054 }
2055 
2056 static int
2057 sparse_list_add(struct pax *pax, int64_t offset, int64_t length)
2058 {
2059 	int64_t last_offset;
2060 	int r;
2061 
2062 	if (pax->sparse_tail == NULL)
2063 		last_offset = 0;
2064 	else {
2065 		last_offset = pax->sparse_tail->offset +
2066 		    pax->sparse_tail->remaining;
2067 	}
2068 	if (last_offset < offset) {
2069 		/* Add a hole block. */
2070 		r = _sparse_list_add_block(pax, last_offset,
2071 		    offset - last_offset, 1);
2072 		if (r != ARCHIVE_OK)
2073 			return (r);
2074 	}
2075 	/* Add data block. */
2076 	return (_sparse_list_add_block(pax, offset, length, 0));
2077 }
2078 
2079 static time_t
2080 get_ustar_max_mtime(void)
2081 {
2082 	/*
2083 	 * Technically, the mtime field in the ustar header can
2084 	 * support 33 bits. We are using all of them to keep
2085 	 * tar/test/test_option_C_mtree.c simple and passing after 2038.
2086 	 * For platforms that use signed 32-bit time values we
2087 	 * use the 32-bit maximum.
2088 	 */
2089 	if (sizeof(time_t) > sizeof(int32_t))
2090 		return (time_t)0x1ffffffff;
2091 	else
2092 		return (time_t)0x7fffffff;
2093 }
2094