1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * Copyright (c) 2010-2012 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: head/lib/libarchive/archive_write_set_format_pax.c 201162 2009-12-29 05:47:46Z kientzle $");
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 
46 struct sparse_block {
47 	struct sparse_block	*next;
48 	int		is_hole;
49 	uint64_t	offset;
50 	uint64_t	remaining;
51 };
52 
53 struct pax {
54 	uint64_t	entry_bytes_remaining;
55 	uint64_t	entry_padding;
56 	struct archive_string	l_url_encoded_name;
57 	struct archive_string	pax_header;
58 	struct archive_string	sparse_map;
59 	size_t			sparse_map_padding;
60 	struct sparse_block	*sparse_list;
61 	struct sparse_block	*sparse_tail;
62 	struct archive_string_conv *sconv_utf8;
63 	int			 opt_binary;
64 };
65 
66 static void		 add_pax_attr(struct archive_string *, const char *key,
67 			     const char *value);
68 static void		 add_pax_attr_int(struct archive_string *,
69 			     const char *key, int64_t value);
70 static void		 add_pax_attr_time(struct archive_string *,
71 			     const char *key, int64_t sec,
72 			     unsigned long nanos);
73 static ssize_t		 archive_write_pax_data(struct archive_write *,
74 			     const void *, size_t);
75 static int		 archive_write_pax_close(struct archive_write *);
76 static int		 archive_write_pax_free(struct archive_write *);
77 static int		 archive_write_pax_finish_entry(struct archive_write *);
78 static int		 archive_write_pax_header(struct archive_write *,
79 			     struct archive_entry *);
80 static int		 archive_write_pax_options(struct archive_write *,
81 			     const char *, const char *);
82 static char		*base64_encode(const char *src, size_t len);
83 static char		*build_gnu_sparse_name(char *dest, const char *src);
84 static char		*build_pax_attribute_name(char *dest, const char *src);
85 static char		*build_ustar_entry_name(char *dest, const char *src,
86 			     size_t src_length, const char *insert);
87 static char		*format_int(char *dest, int64_t);
88 static int		 has_non_ASCII(const char *);
89 static void		 sparse_list_clear(struct pax *);
90 static int		 sparse_list_add(struct pax *, int64_t, int64_t);
91 static char		*url_encode(const char *in);
92 
93 /*
94  * Set output format to 'restricted pax' format.
95  *
96  * This is the same as normal 'pax', but tries to suppress
97  * the pax header whenever possible.  This is the default for
98  * bsdtar, for instance.
99  */
100 int
101 archive_write_set_format_pax_restricted(struct archive *_a)
102 {
103 	struct archive_write *a = (struct archive_write *)_a;
104 	int r;
105 
106 	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
107 	    ARCHIVE_STATE_NEW, "archive_write_set_format_pax_restricted");
108 
109 	r = archive_write_set_format_pax(&a->archive);
110 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_RESTRICTED;
111 	a->archive.archive_format_name = "restricted POSIX pax interchange";
112 	return (r);
113 }
114 
115 /*
116  * Set output format to 'pax' format.
117  */
118 int
119 archive_write_set_format_pax(struct archive *_a)
120 {
121 	struct archive_write *a = (struct archive_write *)_a;
122 	struct pax *pax;
123 
124 	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
125 	    ARCHIVE_STATE_NEW, "archive_write_set_format_pax");
126 
127 	if (a->format_free != NULL)
128 		(a->format_free)(a);
129 
130 	pax = (struct pax *)malloc(sizeof(*pax));
131 	if (pax == NULL) {
132 		archive_set_error(&a->archive, ENOMEM,
133 		    "Can't allocate pax data");
134 		return (ARCHIVE_FATAL);
135 	}
136 	memset(pax, 0, sizeof(*pax));
137 	a->format_data = pax;
138 	a->format_name = "pax";
139 	a->format_options = archive_write_pax_options;
140 	a->format_write_header = archive_write_pax_header;
141 	a->format_write_data = archive_write_pax_data;
142 	a->format_close = archive_write_pax_close;
143 	a->format_free = archive_write_pax_free;
144 	a->format_finish_entry = archive_write_pax_finish_entry;
145 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
146 	a->archive.archive_format_name = "POSIX pax interchange";
147 	return (ARCHIVE_OK);
148 }
149 
150 static int
151 archive_write_pax_options(struct archive_write *a, const char *key,
152     const char *val)
153 {
154 	struct pax *pax = (struct pax *)a->format_data;
155 	int ret = ARCHIVE_FAILED;
156 
157 	if (strcmp(key, "hdrcharset")  == 0) {
158 		/*
159 		 * The character-set we can use are defined in
160 		 * IEEE Std 1003.1-2001
161 		 */
162 		if (val == NULL || val[0] == 0)
163 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
164 			    "pax: hdrcharset option needs a character-set name");
165 		else if (strcmp(val, "BINARY") == 0 ||
166 		    strcmp(val, "binary") == 0) {
167 			/*
168 			 * Specify binary mode. We will not convert
169 			 * filenames, uname and gname to any charsets.
170 			 */
171 			pax->opt_binary = 1;
172 			ret = ARCHIVE_OK;
173 		} else if (strcmp(val, "UTF-8") == 0) {
174 			/*
175 			 * Specify UTF-8 character-set to be used for
176 			 * filenames. This is almost the test that
177 			 * running platform supports the string conversion.
178 			 * Especially libarchive_test needs this trick for
179 			 * its test.
180 			 */
181 			pax->sconv_utf8 = archive_string_conversion_to_charset(
182 			    &(a->archive), "UTF-8", 0);
183 			if (pax->sconv_utf8 == NULL)
184 				ret = ARCHIVE_FATAL;
185 			else
186 				ret = ARCHIVE_OK;
187 		} else
188 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
189 			    "pax: invalid charset name");
190 		return (ret);
191 	}
192 
193 	/* Note: The "warn" return is just to inform the options
194 	 * supervisor that we didn't handle it.  It will generate
195 	 * a suitable error if no one used this option. */
196 	return (ARCHIVE_WARN);
197 }
198 
199 /*
200  * Note: This code assumes that 'nanos' has the same sign as 'sec',
201  * which implies that sec=-1, nanos=200000000 represents -1.2 seconds
202  * and not -0.8 seconds.  This is a pretty pedantic point, as we're
203  * unlikely to encounter many real files created before Jan 1, 1970,
204  * much less ones with timestamps recorded to sub-second resolution.
205  */
206 static void
207 add_pax_attr_time(struct archive_string *as, const char *key,
208     int64_t sec, unsigned long nanos)
209 {
210 	int digit, i;
211 	char *t;
212 	/*
213 	 * Note that each byte contributes fewer than 3 base-10
214 	 * digits, so this will always be big enough.
215 	 */
216 	char tmp[1 + 3*sizeof(sec) + 1 + 3*sizeof(nanos)];
217 
218 	tmp[sizeof(tmp) - 1] = 0;
219 	t = tmp + sizeof(tmp) - 1;
220 
221 	/* Skip trailing zeros in the fractional part. */
222 	for (digit = 0, i = 10; i > 0 && digit == 0; i--) {
223 		digit = nanos % 10;
224 		nanos /= 10;
225 	}
226 
227 	/* Only format the fraction if it's non-zero. */
228 	if (i > 0) {
229 		while (i > 0) {
230 			*--t = "0123456789"[digit];
231 			digit = nanos % 10;
232 			nanos /= 10;
233 			i--;
234 		}
235 		*--t = '.';
236 	}
237 	t = format_int(t, sec);
238 
239 	add_pax_attr(as, key, t);
240 }
241 
242 static char *
243 format_int(char *t, int64_t i)
244 {
245 	uint64_t ui;
246 
247 	if (i < 0)
248 		ui = (i == INT64_MIN) ? (uint64_t)(INT64_MAX) + 1 : (uint64_t)(-i);
249 	else
250 		ui = i;
251 
252 	do {
253 		*--t = "0123456789"[ui % 10];
254 	} while (ui /= 10);
255 	if (i < 0)
256 		*--t = '-';
257 	return (t);
258 }
259 
260 static void
261 add_pax_attr_int(struct archive_string *as, const char *key, int64_t value)
262 {
263 	char tmp[1 + 3 * sizeof(value)];
264 
265 	tmp[sizeof(tmp) - 1] = 0;
266 	add_pax_attr(as, key, format_int(tmp + sizeof(tmp) - 1, value));
267 }
268 
269 /*
270  * Add a key/value attribute to the pax header.  This function handles
271  * the length field and various other syntactic requirements.
272  */
273 static void
274 add_pax_attr(struct archive_string *as, const char *key, const char *value)
275 {
276 	int digits, i, len, next_ten;
277 	char tmp[1 + 3 * sizeof(int)];	/* < 3 base-10 digits per byte */
278 
279 	/*-
280 	 * PAX attributes have the following layout:
281 	 *     <len> <space> <key> <=> <value> <nl>
282 	 */
283 	len = 1 + (int)strlen(key) + 1 + (int)strlen(value) + 1;
284 
285 	/*
286 	 * The <len> field includes the length of the <len> field, so
287 	 * computing the correct length is tricky.  I start by
288 	 * counting the number of base-10 digits in 'len' and
289 	 * computing the next higher power of 10.
290 	 */
291 	next_ten = 1;
292 	digits = 0;
293 	i = len;
294 	while (i > 0) {
295 		i = i / 10;
296 		digits++;
297 		next_ten = next_ten * 10;
298 	}
299 	/*
300 	 * For example, if string without the length field is 99
301 	 * chars, then adding the 2 digit length "99" will force the
302 	 * total length past 100, requiring an extra digit.  The next
303 	 * statement adjusts for this effect.
304 	 */
305 	if (len + digits >= next_ten)
306 		digits++;
307 
308 	/* Now, we have the right length so we can build the line. */
309 	tmp[sizeof(tmp) - 1] = 0;	/* Null-terminate the work area. */
310 	archive_strcat(as, format_int(tmp + sizeof(tmp) - 1, len + digits));
311 	archive_strappend_char(as, ' ');
312 	archive_strcat(as, key);
313 	archive_strappend_char(as, '=');
314 	archive_strcat(as, value);
315 	archive_strappend_char(as, '\n');
316 }
317 
318 static int
319 archive_write_pax_header_xattrs(struct archive_write *a,
320     struct pax *pax, struct archive_entry *entry)
321 {
322 	struct archive_string s;
323 	int i = archive_entry_xattr_reset(entry);
324 
325 	while (i--) {
326 		const char *name;
327 		const void *value;
328 		char *encoded_value;
329 		char *url_encoded_name = NULL, *encoded_name = NULL;
330 		size_t size;
331 		int r;
332 
333 		archive_entry_xattr_next(entry, &name, &value, &size);
334 		url_encoded_name = url_encode(name);
335 		if (url_encoded_name != NULL) {
336 			/* Convert narrow-character to UTF-8. */
337 			r = archive_strcpy_l(&(pax->l_url_encoded_name),
338 			    url_encoded_name, pax->sconv_utf8);
339 			free(url_encoded_name); /* Done with this. */
340 			if (r == 0)
341 				encoded_name = pax->l_url_encoded_name.s;
342 			else if (errno == ENOMEM) {
343 				archive_set_error(&a->archive, ENOMEM,
344 				    "Can't allocate memory for Linkname");
345 				return (ARCHIVE_FATAL);
346 			}
347 		}
348 
349 		encoded_value = base64_encode((const char *)value, size);
350 
351 		if (encoded_name != NULL && encoded_value != NULL) {
352 			archive_string_init(&s);
353 			archive_strcpy(&s, "LIBARCHIVE.xattr.");
354 			archive_strcat(&s, encoded_name);
355 			add_pax_attr(&(pax->pax_header), s.s, encoded_value);
356 			archive_string_free(&s);
357 		}
358 		free(encoded_value);
359 	}
360 	return (ARCHIVE_OK);
361 }
362 
363 static int
364 get_entry_hardlink(struct archive_write *a, struct archive_entry *entry,
365     const char **name, size_t *length, struct archive_string_conv *sc)
366 {
367 	int r;
368 
369 	r = archive_entry_hardlink_l(entry, name, length, sc);
370 	if (r != 0) {
371 		if (errno == ENOMEM) {
372 			archive_set_error(&a->archive, ENOMEM,
373 			    "Can't allocate memory for Linkname");
374 			return (ARCHIVE_FATAL);
375 		}
376 		return (ARCHIVE_WARN);
377 	}
378 	return (ARCHIVE_OK);
379 }
380 
381 static int
382 get_entry_pathname(struct archive_write *a, struct archive_entry *entry,
383     const char **name, size_t *length, struct archive_string_conv *sc)
384 {
385 	int r;
386 
387 	r = archive_entry_pathname_l(entry, name, length, sc);
388 	if (r != 0) {
389 		if (errno == ENOMEM) {
390 			archive_set_error(&a->archive, ENOMEM,
391 			    "Can't allocate memory for Pathname");
392 			return (ARCHIVE_FATAL);
393 		}
394 		return (ARCHIVE_WARN);
395 	}
396 	return (ARCHIVE_OK);
397 }
398 
399 static int
400 get_entry_uname(struct archive_write *a, struct archive_entry *entry,
401     const char **name, size_t *length, struct archive_string_conv *sc)
402 {
403 	int r;
404 
405 	r = archive_entry_uname_l(entry, name, length, sc);
406 	if (r != 0) {
407 		if (errno == ENOMEM) {
408 			archive_set_error(&a->archive, ENOMEM,
409 			    "Can't allocate memory for Uname");
410 			return (ARCHIVE_FATAL);
411 		}
412 		return (ARCHIVE_WARN);
413 	}
414 	return (ARCHIVE_OK);
415 }
416 
417 static int
418 get_entry_gname(struct archive_write *a, struct archive_entry *entry,
419     const char **name, size_t *length, struct archive_string_conv *sc)
420 {
421 	int r;
422 
423 	r = archive_entry_gname_l(entry, name, length, sc);
424 	if (r != 0) {
425 		if (errno == ENOMEM) {
426 			archive_set_error(&a->archive, ENOMEM,
427 			    "Can't allocate memory for Gname");
428 			return (ARCHIVE_FATAL);
429 		}
430 		return (ARCHIVE_WARN);
431 	}
432 	return (ARCHIVE_OK);
433 }
434 
435 static int
436 get_entry_symlink(struct archive_write *a, struct archive_entry *entry,
437     const char **name, size_t *length, struct archive_string_conv *sc)
438 {
439 	int r;
440 
441 	r = archive_entry_symlink_l(entry, name, length, sc);
442 	if (r != 0) {
443 		if (errno == ENOMEM) {
444 			archive_set_error(&a->archive, ENOMEM,
445 			    "Can't allocate memory for Linkname");
446 			return (ARCHIVE_FATAL);
447 		}
448 		return (ARCHIVE_WARN);
449 	}
450 	return (ARCHIVE_OK);
451 }
452 
453 /*
454  * TODO: Consider adding 'comment' and 'charset' fields to
455  * archive_entry so that clients can specify them.  Also, consider
456  * adding generic key/value tags so clients can add arbitrary
457  * key/value data.
458  *
459  * TODO: Break up this 700-line function!!!!  Yowza!
460  */
461 static int
462 archive_write_pax_header(struct archive_write *a,
463     struct archive_entry *entry_original)
464 {
465 	struct archive_entry *entry_main;
466 	const char *p;
467 	const char *suffix;
468 	int need_extension, r, ret;
469 	int sparse_count;
470 	uint64_t sparse_total, real_size;
471 	struct pax *pax;
472 	const char *hardlink;
473 	const char *path = NULL, *linkpath = NULL;
474 	const char *uname = NULL, *gname = NULL;
475 	const void *mac_metadata;
476 	size_t mac_metadata_size;
477 	struct archive_string_conv *sconv;
478 	size_t hardlink_length, path_length, linkpath_length;
479 	size_t uname_length, gname_length;
480 
481 	char paxbuff[512];
482 	char ustarbuff[512];
483 	char ustar_entry_name[256];
484 	char pax_entry_name[256];
485 	char gnu_sparse_name[256];
486 	struct archive_string entry_name;
487 
488 	ret = ARCHIVE_OK;
489 	need_extension = 0;
490 	pax = (struct pax *)a->format_data;
491 
492 	/* Sanity check. */
493 	if (archive_entry_pathname(entry_original) == NULL) {
494 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
495 			  "Can't record entry in tar file without pathname");
496 		return (ARCHIVE_FAILED);
497 	}
498 
499 	/*
500 	 * Choose a header encoding.
501 	 */
502 	if (pax->opt_binary)
503 		sconv = NULL;/* Binary mode. */
504 	else {
505 		/* Header encoding is UTF-8. */
506 		if (pax->sconv_utf8 == NULL) {
507 			/* Initialize the string conversion object
508 			 * we must need */
509 			pax->sconv_utf8 = archive_string_conversion_to_charset(
510 			    &(a->archive), "UTF-8", 1);
511 			if (pax->sconv_utf8 == NULL)
512 				/* Couldn't allocate memory */
513 				return (ARCHIVE_FAILED);
514 		}
515 		sconv = pax->sconv_utf8;
516 	}
517 
518 	r = get_entry_hardlink(a, entry_original, &hardlink,
519 	    &hardlink_length, sconv);
520 	if (r == ARCHIVE_FATAL)
521 		return (r);
522 	else if (r != ARCHIVE_OK) {
523 		r = get_entry_hardlink(a, entry_original, &hardlink,
524 		    &hardlink_length, NULL);
525 		if (r == ARCHIVE_FATAL)
526 			return (r);
527 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
528 		    "Can't translate linkname '%s' to %s", hardlink,
529 		    archive_string_conversion_charset_name(sconv));
530 		ret = ARCHIVE_WARN;
531 		sconv = NULL;/* The header charset switches to binary mode. */
532 	}
533 
534 	/* Make sure this is a type of entry that we can handle here */
535 	if (hardlink == NULL) {
536 		switch (archive_entry_filetype(entry_original)) {
537 		case AE_IFBLK:
538 		case AE_IFCHR:
539 		case AE_IFIFO:
540 		case AE_IFLNK:
541 		case AE_IFREG:
542 			break;
543 		case AE_IFDIR:
544 		{
545 			/*
546 			 * Ensure a trailing '/'.  Modify the original
547 			 * entry so the client sees the change.
548 			 */
549 #if defined(_WIN32) && !defined(__CYGWIN__)
550 			const wchar_t *wp;
551 
552 			wp = archive_entry_pathname_w(entry_original);
553 			if (wp != NULL && wp[wcslen(wp) -1] != L'/') {
554 				struct archive_wstring ws;
555 
556 				archive_string_init(&ws);
557 				path_length = wcslen(wp);
558 				if (archive_wstring_ensure(&ws,
559 				    path_length + 2) == NULL) {
560 					archive_set_error(&a->archive, ENOMEM,
561 					    "Can't allocate pax data");
562 					archive_wstring_free(&ws);
563 					return(ARCHIVE_FATAL);
564 				}
565 				/* Should we keep '\' ? */
566 				if (wp[path_length -1] == L'\\')
567 					path_length--;
568 				archive_wstrncpy(&ws, wp, path_length);
569 				archive_wstrappend_wchar(&ws, L'/');
570 				archive_entry_copy_pathname_w(
571 				    entry_original, ws.s);
572 				archive_wstring_free(&ws);
573 				p = NULL;
574 			} else
575 #endif
576 				p = archive_entry_pathname(entry_original);
577 			/*
578 			 * On Windows, this is a backup operation just in
579 			 * case getting WCS failed. On POSIX, this is a
580 			 * normal operation.
581 			 */
582 			if (p != NULL && p[strlen(p) - 1] != '/') {
583 				struct archive_string as;
584 
585 				archive_string_init(&as);
586 				path_length = strlen(p);
587 				if (archive_string_ensure(&as,
588 				    path_length + 2) == NULL) {
589 					archive_set_error(&a->archive, ENOMEM,
590 					    "Can't allocate pax data");
591 					archive_string_free(&as);
592 					return(ARCHIVE_FATAL);
593 				}
594 #if defined(_WIN32) && !defined(__CYGWIN__)
595 				/* NOTE: This might break the pathname
596 				 * if the current code page is CP932 and
597 				 * the pathname includes a character '\'
598 				 * as a part of its multibyte pathname. */
599 				if (p[strlen(p) -1] == '\\')
600 					path_length--;
601 				else
602 #endif
603 				archive_strncpy(&as, p, path_length);
604 				archive_strappend_char(&as, '/');
605 				archive_entry_copy_pathname(
606 				    entry_original, as.s);
607 				archive_string_free(&as);
608 			}
609 			break;
610 		}
611 		case AE_IFSOCK:
612 			archive_set_error(&a->archive,
613 			    ARCHIVE_ERRNO_FILE_FORMAT,
614 			    "tar format cannot archive socket");
615 			return (ARCHIVE_FAILED);
616 		default:
617 			archive_set_error(&a->archive,
618 			    ARCHIVE_ERRNO_FILE_FORMAT,
619 			    "tar format cannot archive this (type=0%lo)",
620 			    (unsigned long)
621 			    archive_entry_filetype(entry_original));
622 			return (ARCHIVE_FAILED);
623 		}
624 	}
625 
626 	/*
627 	 * If Mac OS metadata blob is here, recurse to write that
628 	 * as a separate entry.  This is really a pretty poor design:
629 	 * In particular, it doubles the overhead for long filenames.
630 	 * TODO: Help Apple folks design something better and figure
631 	 * out how to transition from this legacy format.
632 	 *
633 	 * Note that this code is present on every platform; clients
634 	 * on non-Mac are unlikely to ever provide this data, but
635 	 * applications that copy entries from one archive to another
636 	 * should not lose data just because the local filesystem
637 	 * can't store it.
638 	 */
639 	mac_metadata =
640 	    archive_entry_mac_metadata(entry_original, &mac_metadata_size);
641 	if (mac_metadata != NULL) {
642 		const char *oname;
643 		char *name, *bname;
644 		size_t name_length;
645 		struct archive_entry *extra = archive_entry_new2(&a->archive);
646 
647 		oname = archive_entry_pathname(entry_original);
648 		name_length = strlen(oname);
649 		name = malloc(name_length + 3);
650 		if (name == NULL || extra == NULL) {
651 			/* XXX error message */
652 			archive_entry_free(extra);
653 			free(name);
654 			return (ARCHIVE_FAILED);
655 		}
656 		strcpy(name, oname);
657 		/* Find last '/'; strip trailing '/' characters */
658 		bname = strrchr(name, '/');
659 		while (bname != NULL && bname[1] == '\0') {
660 			*bname = '\0';
661 			bname = strrchr(name, '/');
662 		}
663 		if (bname == NULL) {
664 			memmove(name + 2, name, name_length + 1);
665 			memmove(name, "._", 2);
666 		} else {
667 			bname += 1;
668 			memmove(bname + 2, bname, strlen(bname) + 1);
669 			memmove(bname, "._", 2);
670 		}
671 		archive_entry_copy_pathname(extra, name);
672 		free(name);
673 
674 		archive_entry_set_size(extra, mac_metadata_size);
675 		archive_entry_set_filetype(extra, AE_IFREG);
676 		archive_entry_set_perm(extra,
677 		    archive_entry_perm(entry_original));
678 		archive_entry_set_mtime(extra,
679 		    archive_entry_mtime(entry_original),
680 		    archive_entry_mtime_nsec(entry_original));
681 		archive_entry_set_gid(extra,
682 		    archive_entry_gid(entry_original));
683 		archive_entry_set_gname(extra,
684 		    archive_entry_gname(entry_original));
685 		archive_entry_set_uid(extra,
686 		    archive_entry_uid(entry_original));
687 		archive_entry_set_uname(extra,
688 		    archive_entry_uname(entry_original));
689 
690 		/* Recurse to write the special copyfile entry. */
691 		r = archive_write_pax_header(a, extra);
692 		archive_entry_free(extra);
693 		if (r < ARCHIVE_WARN)
694 			return (r);
695 		if (r < ret)
696 			ret = r;
697 		r = (int)archive_write_pax_data(a, mac_metadata,
698 		    mac_metadata_size);
699 		if (r < ARCHIVE_WARN)
700 			return (r);
701 		if (r < ret)
702 			ret = r;
703 		r = archive_write_pax_finish_entry(a);
704 		if (r < ARCHIVE_WARN)
705 			return (r);
706 		if (r < ret)
707 			ret = r;
708 	}
709 
710 	/* Copy entry so we can modify it as needed. */
711 #if defined(_WIN32) && !defined(__CYGWIN__)
712 	/* Make sure the path separators in pahtname, hardlink and symlink
713 	 * are all slash '/', not the Windows path separator '\'. */
714 	entry_main = __la_win_entry_in_posix_pathseparator(entry_original);
715 	if (entry_main == entry_original)
716 		entry_main = archive_entry_clone(entry_original);
717 #else
718 	entry_main = archive_entry_clone(entry_original);
719 #endif
720 	if (entry_main == NULL) {
721 		archive_set_error(&a->archive, ENOMEM,
722 		    "Can't allocate pax data");
723 		return(ARCHIVE_FATAL);
724 	}
725 	archive_string_empty(&(pax->pax_header)); /* Blank our work area. */
726 	archive_string_empty(&(pax->sparse_map));
727 	sparse_total = 0;
728 	sparse_list_clear(pax);
729 
730 	if (hardlink == NULL &&
731 	    archive_entry_filetype(entry_main) == AE_IFREG)
732 		sparse_count = archive_entry_sparse_reset(entry_main);
733 	else
734 		sparse_count = 0;
735 	if (sparse_count) {
736 		int64_t offset, length, last_offset = 0;
737 		/* Get the last entry of sparse block. */
738 		while (archive_entry_sparse_next(
739 		    entry_main, &offset, &length) == ARCHIVE_OK)
740 			last_offset = offset + length;
741 
742 		/* If the last sparse block does not reach the end of file,
743 		 * We have to add a empty sparse block as the last entry to
744 		 * manage storing file data. */
745 		if (last_offset < archive_entry_size(entry_main))
746 			archive_entry_sparse_add_entry(entry_main,
747 			    archive_entry_size(entry_main), 0);
748 		sparse_count = archive_entry_sparse_reset(entry_main);
749 	}
750 
751 	/*
752 	 * First, check the name fields and see if any of them
753 	 * require binary coding.  If any of them does, then all of
754 	 * them do.
755 	 */
756 	r = get_entry_pathname(a, entry_main, &path, &path_length, sconv);
757 	if (r == ARCHIVE_FATAL)
758 		return (r);
759 	else if (r != ARCHIVE_OK) {
760 		r = get_entry_pathname(a, entry_main, &path,
761 		    &path_length, NULL);
762 		if (r == ARCHIVE_FATAL)
763 			return (r);
764 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
765 		    "Can't translate pathname '%s' to %s", path,
766 		    archive_string_conversion_charset_name(sconv));
767 		ret = ARCHIVE_WARN;
768 		sconv = NULL;/* The header charset switches to binary mode. */
769 	}
770 	r = get_entry_uname(a, entry_main, &uname, &uname_length, sconv);
771 	if (r == ARCHIVE_FATAL)
772 		return (r);
773 	else if (r != ARCHIVE_OK) {
774 		r = get_entry_uname(a, entry_main, &uname, &uname_length, NULL);
775 		if (r == ARCHIVE_FATAL)
776 			return (r);
777 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
778 		    "Can't translate uname '%s' to %s", uname,
779 		    archive_string_conversion_charset_name(sconv));
780 		ret = ARCHIVE_WARN;
781 		sconv = NULL;/* The header charset switches to binary mode. */
782 	}
783 	r = get_entry_gname(a, entry_main, &gname, &gname_length, sconv);
784 	if (r == ARCHIVE_FATAL)
785 		return (r);
786 	else if (r != ARCHIVE_OK) {
787 		r = get_entry_gname(a, entry_main, &gname, &gname_length, NULL);
788 		if (r == ARCHIVE_FATAL)
789 			return (r);
790 		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
791 		    "Can't translate gname '%s' to %s", gname,
792 		    archive_string_conversion_charset_name(sconv));
793 		ret = ARCHIVE_WARN;
794 		sconv = NULL;/* The header charset switches to binary mode. */
795 	}
796 	linkpath = hardlink;
797 	linkpath_length = hardlink_length;
798 	if (linkpath == NULL) {
799 		r = get_entry_symlink(a, entry_main, &linkpath,
800 		    &linkpath_length, sconv);
801 		if (r == ARCHIVE_FATAL)
802 			return (r);
803 		else if (r != ARCHIVE_OK) {
804 			r = get_entry_symlink(a, entry_main, &linkpath,
805 			    &linkpath_length, NULL);
806 			if (r == ARCHIVE_FATAL)
807 				return (r);
808 			archive_set_error(&a->archive,
809 			    ARCHIVE_ERRNO_FILE_FORMAT,
810 			    "Can't translate linkname '%s' to %s", linkpath,
811 			    archive_string_conversion_charset_name(sconv));
812 			ret = ARCHIVE_WARN;
813 			sconv = NULL;
814 		}
815 	}
816 
817 	/* If any string conversions failed, get all attributes
818 	 * in binary-mode. */
819 	if (sconv == NULL && !pax->opt_binary) {
820 		if (hardlink != NULL) {
821 			r = get_entry_hardlink(a, entry_main, &hardlink,
822 			    &hardlink_length, NULL);
823 			if (r == ARCHIVE_FATAL)
824 				return (r);
825 			linkpath = hardlink;
826 			linkpath_length = hardlink_length;
827 		}
828 		r = get_entry_pathname(a, entry_main, &path,
829 		    &path_length, NULL);
830 		if (r == ARCHIVE_FATAL)
831 			return (r);
832 		r = get_entry_uname(a, entry_main, &uname, &uname_length, NULL);
833 		if (r == ARCHIVE_FATAL)
834 			return (r);
835 		r = get_entry_gname(a, entry_main, &gname, &gname_length, NULL);
836 		if (r == ARCHIVE_FATAL)
837 			return (r);
838 	}
839 
840 	/* Store the header encoding first, to be nice to readers. */
841 	if (sconv == NULL)
842 		add_pax_attr(&(pax->pax_header), "hdrcharset", "BINARY");
843 
844 
845 	/*
846 	 * If name is too long, or has non-ASCII characters, add
847 	 * 'path' to pax extended attrs.  (Note that an unconvertible
848 	 * name must have non-ASCII characters.)
849 	 */
850 	if (has_non_ASCII(path)) {
851 		/* We have non-ASCII characters. */
852 		add_pax_attr(&(pax->pax_header), "path", path);
853 		archive_entry_set_pathname(entry_main,
854 		    build_ustar_entry_name(ustar_entry_name,
855 			path, path_length, NULL));
856 		need_extension = 1;
857 	} else {
858 		/* We have an all-ASCII path; we'd like to just store
859 		 * it in the ustar header if it will fit.  Yes, this
860 		 * duplicates some of the logic in
861 		 * archive_write_set_format_ustar.c
862 		 */
863 		if (path_length <= 100) {
864 			/* Fits in the old 100-char tar name field. */
865 		} else {
866 			/* Find largest suffix that will fit. */
867 			/* Note: strlen() > 100, so strlen() - 100 - 1 >= 0 */
868 			suffix = strchr(path + path_length - 100 - 1, '/');
869 			/* Don't attempt an empty prefix. */
870 			if (suffix == path)
871 				suffix = strchr(suffix + 1, '/');
872 			/* We can put it in the ustar header if it's
873 			 * all ASCII and it's either <= 100 characters
874 			 * or can be split at a '/' into a prefix <=
875 			 * 155 chars and a suffix <= 100 chars.  (Note
876 			 * the strchr() above will return NULL exactly
877 			 * when the path can't be split.)
878 			 */
879 			if (suffix == NULL       /* Suffix > 100 chars. */
880 			    || suffix[1] == '\0'    /* empty suffix */
881 			    || suffix - path > 155)  /* Prefix > 155 chars */
882 			{
883 				add_pax_attr(&(pax->pax_header), "path", path);
884 				archive_entry_set_pathname(entry_main,
885 				    build_ustar_entry_name(ustar_entry_name,
886 					path, path_length, NULL));
887 				need_extension = 1;
888 			}
889 		}
890 	}
891 
892 	if (linkpath != NULL) {
893 		/* If link name is too long or has non-ASCII characters, add
894 		 * 'linkpath' to pax extended attrs. */
895 		if (linkpath_length > 100 || has_non_ASCII(linkpath)) {
896 			add_pax_attr(&(pax->pax_header), "linkpath", linkpath);
897 			if (linkpath_length > 100) {
898 				if (hardlink != NULL)
899 					archive_entry_set_hardlink(entry_main,
900 					    "././@LongHardLink");
901 				else
902 					archive_entry_set_symlink(entry_main,
903 					    "././@LongSymLink");
904 			}
905 			need_extension = 1;
906 		}
907 	}
908 	/* Save a pathname since it will be renamed if `entry_main` has
909 	 * sparse blocks. */
910 	archive_string_init(&entry_name);
911 	archive_strcpy(&entry_name, archive_entry_pathname(entry_main));
912 
913 	/* If file size is too large, add 'size' to pax extended attrs. */
914 	if (archive_entry_size(entry_main) >= (((int64_t)1) << 33)) {
915 		add_pax_attr_int(&(pax->pax_header), "size",
916 		    archive_entry_size(entry_main));
917 		need_extension = 1;
918 	}
919 
920 	/* If numeric GID is too large, add 'gid' to pax extended attrs. */
921 	if ((unsigned int)archive_entry_gid(entry_main) >= (1 << 18)) {
922 		add_pax_attr_int(&(pax->pax_header), "gid",
923 		    archive_entry_gid(entry_main));
924 		need_extension = 1;
925 	}
926 
927 	/* If group name is too large or has non-ASCII characters, add
928 	 * 'gname' to pax extended attrs. */
929 	if (gname != NULL) {
930 		if (gname_length > 31 || has_non_ASCII(gname)) {
931 			add_pax_attr(&(pax->pax_header), "gname", gname);
932 			need_extension = 1;
933 		}
934 	}
935 
936 	/* If numeric UID is too large, add 'uid' to pax extended attrs. */
937 	if ((unsigned int)archive_entry_uid(entry_main) >= (1 << 18)) {
938 		add_pax_attr_int(&(pax->pax_header), "uid",
939 		    archive_entry_uid(entry_main));
940 		need_extension = 1;
941 	}
942 
943 	/* Add 'uname' to pax extended attrs if necessary. */
944 	if (uname != NULL) {
945 		if (uname_length > 31 || has_non_ASCII(uname)) {
946 			add_pax_attr(&(pax->pax_header), "uname", uname);
947 			need_extension = 1;
948 		}
949 	}
950 
951 	/*
952 	 * POSIX/SUSv3 doesn't provide a standard key for large device
953 	 * numbers.  I use the same keys here that Joerg Schilling
954 	 * used for 'star.'  (Which, somewhat confusingly, are called
955 	 * "devXXX" even though they code "rdev" values.)  No doubt,
956 	 * other implementations use other keys.  Note that there's no
957 	 * reason we can't write the same information into a number of
958 	 * different keys.
959 	 *
960 	 * Of course, this is only needed for block or char device entries.
961 	 */
962 	if (archive_entry_filetype(entry_main) == AE_IFBLK
963 	    || archive_entry_filetype(entry_main) == AE_IFCHR) {
964 		/*
965 		 * If rdevmajor is too large, add 'SCHILY.devmajor' to
966 		 * extended attributes.
967 		 */
968 		int rdevmajor, rdevminor;
969 		rdevmajor = archive_entry_rdevmajor(entry_main);
970 		rdevminor = archive_entry_rdevminor(entry_main);
971 		if (rdevmajor >= (1 << 18)) {
972 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devmajor",
973 			    rdevmajor);
974 			/*
975 			 * Non-strict formatting below means we don't
976 			 * have to truncate here.  Not truncating improves
977 			 * the chance that some more modern tar archivers
978 			 * (such as GNU tar 1.13) can restore the full
979 			 * value even if they don't understand the pax
980 			 * extended attributes.  See my rant below about
981 			 * file size fields for additional details.
982 			 */
983 			/* archive_entry_set_rdevmajor(entry_main,
984 			   rdevmajor & ((1 << 18) - 1)); */
985 			need_extension = 1;
986 		}
987 
988 		/*
989 		 * If devminor is too large, add 'SCHILY.devminor' to
990 		 * extended attributes.
991 		 */
992 		if (rdevminor >= (1 << 18)) {
993 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devminor",
994 			    rdevminor);
995 			/* Truncation is not necessary here, either. */
996 			/* archive_entry_set_rdevminor(entry_main,
997 			   rdevminor & ((1 << 18) - 1)); */
998 			need_extension = 1;
999 		}
1000 	}
1001 
1002 	/*
1003 	 * Technically, the mtime field in the ustar header can
1004 	 * support 33 bits, but many platforms use signed 32-bit time
1005 	 * values.  The cutoff of 0x7fffffff here is a compromise.
1006 	 * Yes, this check is duplicated just below; this helps to
1007 	 * avoid writing an mtime attribute just to handle a
1008 	 * high-resolution timestamp in "restricted pax" mode.
1009 	 */
1010 	if (!need_extension &&
1011 	    ((archive_entry_mtime(entry_main) < 0)
1012 		|| (archive_entry_mtime(entry_main) >= 0x7fffffff)))
1013 		need_extension = 1;
1014 
1015 	/* I use a star-compatible file flag attribute. */
1016 	p = archive_entry_fflags_text(entry_main);
1017 	if (!need_extension && p != NULL  &&  *p != '\0')
1018 		need_extension = 1;
1019 
1020 	/* If there are non-trivial ACL entries, we need an extension. */
1021 	if (!need_extension && archive_entry_acl_count(entry_original,
1022 		ARCHIVE_ENTRY_ACL_TYPE_ACCESS) > 0)
1023 		need_extension = 1;
1024 
1025 	/* If there are non-trivial ACL entries, we need an extension. */
1026 	if (!need_extension && archive_entry_acl_count(entry_original,
1027 		ARCHIVE_ENTRY_ACL_TYPE_DEFAULT) > 0)
1028 		need_extension = 1;
1029 
1030 	/* If there are extended attributes, we need an extension */
1031 	if (!need_extension && archive_entry_xattr_count(entry_original) > 0)
1032 		need_extension = 1;
1033 
1034 	/* If there are sparse info, we need an extension */
1035 	if (!need_extension && sparse_count > 0)
1036 		need_extension = 1;
1037 
1038 	/*
1039 	 * Libarchive used to include these in extended headers for
1040 	 * restricted pax format, but that confused people who
1041 	 * expected ustar-like time semantics.  So now we only include
1042 	 * them in full pax format.
1043 	 */
1044 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED) {
1045 		if (archive_entry_ctime(entry_main) != 0  ||
1046 		    archive_entry_ctime_nsec(entry_main) != 0)
1047 			add_pax_attr_time(&(pax->pax_header), "ctime",
1048 			    archive_entry_ctime(entry_main),
1049 			    archive_entry_ctime_nsec(entry_main));
1050 
1051 		if (archive_entry_atime(entry_main) != 0 ||
1052 		    archive_entry_atime_nsec(entry_main) != 0)
1053 			add_pax_attr_time(&(pax->pax_header), "atime",
1054 			    archive_entry_atime(entry_main),
1055 			    archive_entry_atime_nsec(entry_main));
1056 
1057 		/* Store birth/creationtime only if it's earlier than mtime */
1058 		if (archive_entry_birthtime_is_set(entry_main) &&
1059 		    archive_entry_birthtime(entry_main)
1060 		    < archive_entry_mtime(entry_main))
1061 			add_pax_attr_time(&(pax->pax_header),
1062 			    "LIBARCHIVE.creationtime",
1063 			    archive_entry_birthtime(entry_main),
1064 			    archive_entry_birthtime_nsec(entry_main));
1065 	}
1066 
1067 	/*
1068 	 * The following items are handled differently in "pax
1069 	 * restricted" format.  In particular, in "pax restricted"
1070 	 * format they won't be added unless need_extension is
1071 	 * already set (we're already generating an extended header, so
1072 	 * may as well include these).
1073 	 */
1074 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED ||
1075 	    need_extension) {
1076 		if (archive_entry_mtime(entry_main) < 0  ||
1077 		    archive_entry_mtime(entry_main) >= 0x7fffffff  ||
1078 		    archive_entry_mtime_nsec(entry_main) != 0)
1079 			add_pax_attr_time(&(pax->pax_header), "mtime",
1080 			    archive_entry_mtime(entry_main),
1081 			    archive_entry_mtime_nsec(entry_main));
1082 
1083 		/* I use a star-compatible file flag attribute. */
1084 		p = archive_entry_fflags_text(entry_main);
1085 		if (p != NULL  &&  *p != '\0')
1086 			add_pax_attr(&(pax->pax_header), "SCHILY.fflags", p);
1087 
1088 		/* I use star-compatible ACL attributes. */
1089 		r = archive_entry_acl_text_l(entry_original,
1090 		    ARCHIVE_ENTRY_ACL_TYPE_ACCESS |
1091 		    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID,
1092 		    &p, NULL, pax->sconv_utf8);
1093 		if (r != 0) {
1094 			if (errno == ENOMEM) {
1095 				archive_set_error(&a->archive, ENOMEM,
1096 				    "Can't allocate memory for "
1097 				    "ACL.access");
1098 				return (ARCHIVE_FATAL);
1099 			}
1100 			archive_set_error(&a->archive,
1101 			    ARCHIVE_ERRNO_FILE_FORMAT,
1102 			    "Can't translate ACL.access to UTF-8");
1103 			ret = ARCHIVE_WARN;
1104 		} else if (p != NULL && *p != '\0') {
1105 			add_pax_attr(&(pax->pax_header),
1106 			    "SCHILY.acl.access", p);
1107 		}
1108 		r = archive_entry_acl_text_l(entry_original,
1109 		    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT |
1110 		    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID,
1111 		    &p, NULL, pax->sconv_utf8);
1112 		if (r != 0) {
1113 			if (errno == ENOMEM) {
1114 				archive_set_error(&a->archive, ENOMEM,
1115 				    "Can't allocate memory for "
1116 				    "ACL.default");
1117 				return (ARCHIVE_FATAL);
1118 			}
1119 			archive_set_error(&a->archive,
1120 			    ARCHIVE_ERRNO_FILE_FORMAT,
1121 			    "Can't translate ACL.default to UTF-8");
1122 			ret = ARCHIVE_WARN;
1123 		} else if (p != NULL && *p != '\0') {
1124 			add_pax_attr(&(pax->pax_header),
1125 			    "SCHILY.acl.default", p);
1126 		}
1127 
1128 		/* We use GNU-tar-compatible sparse attributes. */
1129 		if (sparse_count > 0) {
1130 			int64_t soffset, slength;
1131 
1132 			add_pax_attr_int(&(pax->pax_header),
1133 			    "GNU.sparse.major", 1);
1134 			add_pax_attr_int(&(pax->pax_header),
1135 			    "GNU.sparse.minor", 0);
1136 			add_pax_attr(&(pax->pax_header),
1137 			    "GNU.sparse.name", entry_name.s);
1138 			add_pax_attr_int(&(pax->pax_header),
1139 			    "GNU.sparse.realsize",
1140 			    archive_entry_size(entry_main));
1141 
1142 			/* Rename the file name which will be used for
1143 			 * ustar header to a special name, which GNU
1144 			 * PAX Format 1.0 requires */
1145 			archive_entry_set_pathname(entry_main,
1146 			    build_gnu_sparse_name(gnu_sparse_name,
1147 			        entry_name.s));
1148 
1149 			/*
1150 			 * - Make a sparse map, which will precede a file data.
1151 			 * - Get the total size of available data of sparse.
1152 			 */
1153 			archive_string_sprintf(&(pax->sparse_map), "%d\n",
1154 			    sparse_count);
1155 			while (archive_entry_sparse_next(entry_main,
1156 			    &soffset, &slength) == ARCHIVE_OK) {
1157 				archive_string_sprintf(&(pax->sparse_map),
1158 				    "%jd\n%jd\n",
1159 				    (intmax_t)soffset,
1160 				    (intmax_t)slength);
1161 				sparse_total += slength;
1162 				if (sparse_list_add(pax, soffset, slength)
1163 				    != ARCHIVE_OK) {
1164 					archive_set_error(&a->archive,
1165 					    ENOMEM,
1166 					    "Can't allocate memory");
1167 					archive_entry_free(entry_main);
1168 					archive_string_free(&entry_name);
1169 					return (ARCHIVE_FATAL);
1170 				}
1171 			}
1172 		}
1173 
1174 		/* Store extended attributes */
1175 		if (archive_write_pax_header_xattrs(a, pax, entry_original)
1176 		    == ARCHIVE_FATAL) {
1177 			archive_entry_free(entry_main);
1178 			archive_string_free(&entry_name);
1179 			return (ARCHIVE_FATAL);
1180 		}
1181 	}
1182 
1183 	/* Only regular files have data. */
1184 	if (archive_entry_filetype(entry_main) != AE_IFREG)
1185 		archive_entry_set_size(entry_main, 0);
1186 
1187 	/*
1188 	 * Pax-restricted does not store data for hardlinks, in order
1189 	 * to improve compatibility with ustar.
1190 	 */
1191 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE &&
1192 	    hardlink != NULL)
1193 		archive_entry_set_size(entry_main, 0);
1194 
1195 	/*
1196 	 * XXX Full pax interchange format does permit a hardlink
1197 	 * entry to have data associated with it.  I'm not supporting
1198 	 * that here because the client expects me to tell them whether
1199 	 * or not this format expects data for hardlinks.  If I
1200 	 * don't check here, then every pax archive will end up with
1201 	 * duplicated data for hardlinks.  Someday, there may be
1202 	 * need to select this behavior, in which case the following
1203 	 * will need to be revisited. XXX
1204 	 */
1205 	if (hardlink != NULL)
1206 		archive_entry_set_size(entry_main, 0);
1207 
1208 	/* Save a real file size. */
1209 	real_size = archive_entry_size(entry_main);
1210 	/*
1211 	 * Overwrite a file size by the total size of sparse blocks and
1212 	 * the size of sparse map info. That file size is the length of
1213 	 * the data, which we will exactly store into an archive file.
1214 	 */
1215 	if (archive_strlen(&(pax->sparse_map))) {
1216 		size_t mapsize = archive_strlen(&(pax->sparse_map));
1217 		pax->sparse_map_padding = 0x1ff & (-(ssize_t)mapsize);
1218 		archive_entry_set_size(entry_main,
1219 		    mapsize + pax->sparse_map_padding + sparse_total);
1220 	}
1221 
1222 	/* Format 'ustar' header for main entry.
1223 	 *
1224 	 * The trouble with file size: If the reader can't understand
1225 	 * the file size, they may not be able to locate the next
1226 	 * entry and the rest of the archive is toast.  Pax-compliant
1227 	 * readers are supposed to ignore the file size in the main
1228 	 * header, so the question becomes how to maximize portability
1229 	 * for readers that don't support pax attribute extensions.
1230 	 * For maximum compatibility, I permit numeric extensions in
1231 	 * the main header so that the file size stored will always be
1232 	 * correct, even if it's in a format that only some
1233 	 * implementations understand.  The technique used here is:
1234 	 *
1235 	 *  a) If possible, follow the standard exactly.  This handles
1236 	 *  files up to 8 gigabytes minus 1.
1237 	 *
1238 	 *  b) If that fails, try octal but omit the field terminator.
1239 	 *  That handles files up to 64 gigabytes minus 1.
1240 	 *
1241 	 *  c) Otherwise, use base-256 extensions.  That handles files
1242 	 *  up to 2^63 in this implementation, with the potential to
1243 	 *  go up to 2^94.  That should hold us for a while. ;-)
1244 	 *
1245 	 * The non-strict formatter uses similar logic for other
1246 	 * numeric fields, though they're less critical.
1247 	 */
1248 	if (__archive_write_format_header_ustar(a, ustarbuff, entry_main, -1, 0,
1249 	    NULL) == ARCHIVE_FATAL)
1250 		return (ARCHIVE_FATAL);
1251 
1252 	/* If we built any extended attributes, write that entry first. */
1253 	if (archive_strlen(&(pax->pax_header)) > 0) {
1254 		struct archive_entry *pax_attr_entry;
1255 		time_t s;
1256 		int64_t uid, gid;
1257 		int mode;
1258 
1259 		pax_attr_entry = archive_entry_new2(&a->archive);
1260 		p = entry_name.s;
1261 		archive_entry_set_pathname(pax_attr_entry,
1262 		    build_pax_attribute_name(pax_entry_name, p));
1263 		archive_entry_set_size(pax_attr_entry,
1264 		    archive_strlen(&(pax->pax_header)));
1265 		/* Copy uid/gid (but clip to ustar limits). */
1266 		uid = archive_entry_uid(entry_main);
1267 		if (uid >= 1 << 18)
1268 			uid = (1 << 18) - 1;
1269 		archive_entry_set_uid(pax_attr_entry, uid);
1270 		gid = archive_entry_gid(entry_main);
1271 		if (gid >= 1 << 18)
1272 			gid = (1 << 18) - 1;
1273 		archive_entry_set_gid(pax_attr_entry, gid);
1274 		/* Copy mode over (but not setuid/setgid bits) */
1275 		mode = archive_entry_mode(entry_main);
1276 #ifdef S_ISUID
1277 		mode &= ~S_ISUID;
1278 #endif
1279 #ifdef S_ISGID
1280 		mode &= ~S_ISGID;
1281 #endif
1282 #ifdef S_ISVTX
1283 		mode &= ~S_ISVTX;
1284 #endif
1285 		archive_entry_set_mode(pax_attr_entry, mode);
1286 
1287 		/* Copy uname/gname. */
1288 		archive_entry_set_uname(pax_attr_entry,
1289 		    archive_entry_uname(entry_main));
1290 		archive_entry_set_gname(pax_attr_entry,
1291 		    archive_entry_gname(entry_main));
1292 
1293 		/* Copy mtime, but clip to ustar limits. */
1294 		s = archive_entry_mtime(entry_main);
1295 		if (s < 0) { s = 0; }
1296 		if (s >= 0x7fffffff) { s = 0x7fffffff; }
1297 		archive_entry_set_mtime(pax_attr_entry, s, 0);
1298 
1299 		/* Standard ustar doesn't support atime. */
1300 		archive_entry_set_atime(pax_attr_entry, 0, 0);
1301 
1302 		/* Standard ustar doesn't support ctime. */
1303 		archive_entry_set_ctime(pax_attr_entry, 0, 0);
1304 
1305 		r = __archive_write_format_header_ustar(a, paxbuff,
1306 		    pax_attr_entry, 'x', 1, NULL);
1307 
1308 		archive_entry_free(pax_attr_entry);
1309 
1310 		/* Note that the 'x' header shouldn't ever fail to format */
1311 		if (r < ARCHIVE_WARN) {
1312 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1313 			    "archive_write_pax_header: "
1314 			    "'x' header failed?!  This can't happen.\n");
1315 			return (ARCHIVE_FATAL);
1316 		} else if (r < ret)
1317 			ret = r;
1318 		r = __archive_write_output(a, paxbuff, 512);
1319 		if (r != ARCHIVE_OK) {
1320 			sparse_list_clear(pax);
1321 			pax->entry_bytes_remaining = 0;
1322 			pax->entry_padding = 0;
1323 			return (ARCHIVE_FATAL);
1324 		}
1325 
1326 		pax->entry_bytes_remaining = archive_strlen(&(pax->pax_header));
1327 		pax->entry_padding =
1328 		    0x1ff & (-(int64_t)pax->entry_bytes_remaining);
1329 
1330 		r = __archive_write_output(a, pax->pax_header.s,
1331 		    archive_strlen(&(pax->pax_header)));
1332 		if (r != ARCHIVE_OK) {
1333 			/* If a write fails, we're pretty much toast. */
1334 			return (ARCHIVE_FATAL);
1335 		}
1336 		/* Pad out the end of the entry. */
1337 		r = __archive_write_nulls(a, (size_t)pax->entry_padding);
1338 		if (r != ARCHIVE_OK) {
1339 			/* If a write fails, we're pretty much toast. */
1340 			return (ARCHIVE_FATAL);
1341 		}
1342 		pax->entry_bytes_remaining = pax->entry_padding = 0;
1343 	}
1344 
1345 	/* Write the header for main entry. */
1346 	r = __archive_write_output(a, ustarbuff, 512);
1347 	if (r != ARCHIVE_OK)
1348 		return (r);
1349 
1350 	/*
1351 	 * Inform the client of the on-disk size we're using, so
1352 	 * they can avoid unnecessarily writing a body for something
1353 	 * that we're just going to ignore.
1354 	 */
1355 	archive_entry_set_size(entry_original, real_size);
1356 	if (pax->sparse_list == NULL && real_size > 0) {
1357 		/* This is not a sparse file but we handle its data as
1358 		 * a sparse block. */
1359 		sparse_list_add(pax, 0, real_size);
1360 		sparse_total = real_size;
1361 	}
1362 	pax->entry_padding = 0x1ff & (-(int64_t)sparse_total);
1363 	archive_entry_free(entry_main);
1364 	archive_string_free(&entry_name);
1365 
1366 	return (ret);
1367 }
1368 
1369 /*
1370  * We need a valid name for the regular 'ustar' entry.  This routine
1371  * tries to hack something more-or-less reasonable.
1372  *
1373  * The approach here tries to preserve leading dir names.  We do so by
1374  * working with four sections:
1375  *   1) "prefix" directory names,
1376  *   2) "suffix" directory names,
1377  *   3) inserted dir name (optional),
1378  *   4) filename.
1379  *
1380  * These sections must satisfy the following requirements:
1381  *   * Parts 1 & 2 together form an initial portion of the dir name.
1382  *   * Part 3 is specified by the caller.  (It should not contain a leading
1383  *     or trailing '/'.)
1384  *   * Part 4 forms an initial portion of the base filename.
1385  *   * The filename must be <= 99 chars to fit the ustar 'name' field.
1386  *   * Parts 2, 3, 4 together must be <= 99 chars to fit the ustar 'name' fld.
1387  *   * Part 1 must be <= 155 chars to fit the ustar 'prefix' field.
1388  *   * If the original name ends in a '/', the new name must also end in a '/'
1389  *   * Trailing '/.' sequences may be stripped.
1390  *
1391  * Note: Recall that the ustar format does not store the '/' separating
1392  * parts 1 & 2, but does store the '/' separating parts 2 & 3.
1393  */
1394 static char *
1395 build_ustar_entry_name(char *dest, const char *src, size_t src_length,
1396     const char *insert)
1397 {
1398 	const char *prefix, *prefix_end;
1399 	const char *suffix, *suffix_end;
1400 	const char *filename, *filename_end;
1401 	char *p;
1402 	int need_slash = 0; /* Was there a trailing slash? */
1403 	size_t suffix_length = 99;
1404 	size_t insert_length;
1405 
1406 	/* Length of additional dir element to be added. */
1407 	if (insert == NULL)
1408 		insert_length = 0;
1409 	else
1410 		/* +2 here allows for '/' before and after the insert. */
1411 		insert_length = strlen(insert) + 2;
1412 
1413 	/* Step 0: Quick bailout in a common case. */
1414 	if (src_length < 100 && insert == NULL) {
1415 		strncpy(dest, src, src_length);
1416 		dest[src_length] = '\0';
1417 		return (dest);
1418 	}
1419 
1420 	/* Step 1: Locate filename and enforce the length restriction. */
1421 	filename_end = src + src_length;
1422 	/* Remove trailing '/' chars and '/.' pairs. */
1423 	for (;;) {
1424 		if (filename_end > src && filename_end[-1] == '/') {
1425 			filename_end --;
1426 			need_slash = 1; /* Remember to restore trailing '/'. */
1427 			continue;
1428 		}
1429 		if (filename_end > src + 1 && filename_end[-1] == '.'
1430 		    && filename_end[-2] == '/') {
1431 			filename_end -= 2;
1432 			need_slash = 1; /* "foo/." will become "foo/" */
1433 			continue;
1434 		}
1435 		break;
1436 	}
1437 	if (need_slash)
1438 		suffix_length--;
1439 	/* Find start of filename. */
1440 	filename = filename_end - 1;
1441 	while ((filename > src) && (*filename != '/'))
1442 		filename --;
1443 	if ((*filename == '/') && (filename < filename_end - 1))
1444 		filename ++;
1445 	/* Adjust filename_end so that filename + insert fits in 99 chars. */
1446 	suffix_length -= insert_length;
1447 	if (filename_end > filename + suffix_length)
1448 		filename_end = filename + suffix_length;
1449 	/* Calculate max size for "suffix" section (#3 above). */
1450 	suffix_length -= filename_end - filename;
1451 
1452 	/* Step 2: Locate the "prefix" section of the dirname, including
1453 	 * trailing '/'. */
1454 	prefix = src;
1455 	prefix_end = prefix + 155;
1456 	if (prefix_end > filename)
1457 		prefix_end = filename;
1458 	while (prefix_end > prefix && *prefix_end != '/')
1459 		prefix_end--;
1460 	if ((prefix_end < filename) && (*prefix_end == '/'))
1461 		prefix_end++;
1462 
1463 	/* Step 3: Locate the "suffix" section of the dirname,
1464 	 * including trailing '/'. */
1465 	suffix = prefix_end;
1466 	suffix_end = suffix + suffix_length; /* Enforce limit. */
1467 	if (suffix_end > filename)
1468 		suffix_end = filename;
1469 	if (suffix_end < suffix)
1470 		suffix_end = suffix;
1471 	while (suffix_end > suffix && *suffix_end != '/')
1472 		suffix_end--;
1473 	if ((suffix_end < filename) && (*suffix_end == '/'))
1474 		suffix_end++;
1475 
1476 	/* Step 4: Build the new name. */
1477 	/* The OpenBSD strlcpy function is safer, but less portable. */
1478 	/* Rather than maintain two versions, just use the strncpy version. */
1479 	p = dest;
1480 	if (prefix_end > prefix) {
1481 		strncpy(p, prefix, prefix_end - prefix);
1482 		p += prefix_end - prefix;
1483 	}
1484 	if (suffix_end > suffix) {
1485 		strncpy(p, suffix, suffix_end - suffix);
1486 		p += suffix_end - suffix;
1487 	}
1488 	if (insert != NULL) {
1489 		/* Note: assume insert does not have leading or trailing '/' */
1490 		strcpy(p, insert);
1491 		p += strlen(insert);
1492 		*p++ = '/';
1493 	}
1494 	strncpy(p, filename, filename_end - filename);
1495 	p += filename_end - filename;
1496 	if (need_slash)
1497 		*p++ = '/';
1498 	*p = '\0';
1499 
1500 	return (dest);
1501 }
1502 
1503 /*
1504  * The ustar header for the pax extended attributes must have a
1505  * reasonable name:  SUSv3 requires 'dirname'/PaxHeader.'pid'/'filename'
1506  * where 'pid' is the PID of the archiving process.  Unfortunately,
1507  * that makes testing a pain since the output varies for each run,
1508  * so I'm sticking with the simpler 'dirname'/PaxHeader/'filename'
1509  * for now.  (Someday, I'll make this settable.  Then I can use the
1510  * SUS recommendation as default and test harnesses can override it
1511  * to get predictable results.)
1512  *
1513  * Joerg Schilling has argued that this is unnecessary because, in
1514  * practice, if the pax extended attributes get extracted as regular
1515  * files, no one is going to bother reading those attributes to
1516  * manually restore them.  Based on this, 'star' uses
1517  * /tmp/PaxHeader/'basename' as the ustar header name.  This is a
1518  * tempting argument, in part because it's simpler than the SUSv3
1519  * recommendation, but I'm not entirely convinced.  I'm also
1520  * uncomfortable with the fact that "/tmp" is a Unix-ism.
1521  *
1522  * The following routine leverages build_ustar_entry_name() above and
1523  * so is simpler than you might think.  It just needs to provide the
1524  * additional path element and handle a few pathological cases).
1525  */
1526 static char *
1527 build_pax_attribute_name(char *dest, const char *src)
1528 {
1529 	char buff[64];
1530 	const char *p;
1531 
1532 	/* Handle the null filename case. */
1533 	if (src == NULL || *src == '\0') {
1534 		strcpy(dest, "PaxHeader/blank");
1535 		return (dest);
1536 	}
1537 
1538 	/* Prune final '/' and other unwanted final elements. */
1539 	p = src + strlen(src);
1540 	for (;;) {
1541 		/* Ends in "/", remove the '/' */
1542 		if (p > src && p[-1] == '/') {
1543 			--p;
1544 			continue;
1545 		}
1546 		/* Ends in "/.", remove the '.' */
1547 		if (p > src + 1 && p[-1] == '.'
1548 		    && p[-2] == '/') {
1549 			--p;
1550 			continue;
1551 		}
1552 		break;
1553 	}
1554 
1555 	/* Pathological case: After above, there was nothing left.
1556 	 * This includes "/." "/./." "/.//./." etc. */
1557 	if (p == src) {
1558 		strcpy(dest, "/PaxHeader/rootdir");
1559 		return (dest);
1560 	}
1561 
1562 	/* Convert unadorned "." into a suitable filename. */
1563 	if (*src == '.' && p == src + 1) {
1564 		strcpy(dest, "PaxHeader/currentdir");
1565 		return (dest);
1566 	}
1567 
1568 	/*
1569 	 * TODO: Push this string into the 'pax' structure to avoid
1570 	 * recomputing it every time.  That will also open the door
1571 	 * to having clients override it.
1572 	 */
1573 #if HAVE_GETPID && 0  /* Disable this for now; see above comment. */
1574 	sprintf(buff, "PaxHeader.%d", getpid());
1575 #else
1576 	/* If the platform can't fetch the pid, don't include it. */
1577 	strcpy(buff, "PaxHeader");
1578 #endif
1579 	/* General case: build a ustar-compatible name adding
1580 	 * "/PaxHeader/". */
1581 	build_ustar_entry_name(dest, src, p - src, buff);
1582 
1583 	return (dest);
1584 }
1585 
1586 /*
1587  * GNU PAX Format 1.0 requires the special name, which pattern is:
1588  * <dir>/GNUSparseFile.<pid>/<original file name>
1589  *
1590  * This function is used for only Sparse file, a file type of which
1591  * is regular file.
1592  */
1593 static char *
1594 build_gnu_sparse_name(char *dest, const char *src)
1595 {
1596 	char buff[64];
1597 	const char *p;
1598 
1599 	/* Handle the null filename case. */
1600 	if (src == NULL || *src == '\0') {
1601 		strcpy(dest, "GNUSparseFile/blank");
1602 		return (dest);
1603 	}
1604 
1605 	/* Prune final '/' and other unwanted final elements. */
1606 	p = src + strlen(src);
1607 	for (;;) {
1608 		/* Ends in "/", remove the '/' */
1609 		if (p > src && p[-1] == '/') {
1610 			--p;
1611 			continue;
1612 		}
1613 		/* Ends in "/.", remove the '.' */
1614 		if (p > src + 1 && p[-1] == '.'
1615 		    && p[-2] == '/') {
1616 			--p;
1617 			continue;
1618 		}
1619 		break;
1620 	}
1621 
1622 #if HAVE_GETPID && 0  /* Disable this as pax attribute name. */
1623 	sprintf(buff, "GNUSparseFile.%d", getpid());
1624 #else
1625 	/* If the platform can't fetch the pid, don't include it. */
1626 	strcpy(buff, "GNUSparseFile");
1627 #endif
1628 	/* General case: build a ustar-compatible name adding
1629 	 * "/GNUSparseFile/". */
1630 	build_ustar_entry_name(dest, src, p - src, buff);
1631 
1632 	return (dest);
1633 }
1634 
1635 /* Write two null blocks for the end of archive */
1636 static int
1637 archive_write_pax_close(struct archive_write *a)
1638 {
1639 	return (__archive_write_nulls(a, 512 * 2));
1640 }
1641 
1642 static int
1643 archive_write_pax_free(struct archive_write *a)
1644 {
1645 	struct pax *pax;
1646 
1647 	pax = (struct pax *)a->format_data;
1648 	if (pax == NULL)
1649 		return (ARCHIVE_OK);
1650 
1651 	archive_string_free(&pax->pax_header);
1652 	archive_string_free(&pax->sparse_map);
1653 	archive_string_free(&pax->l_url_encoded_name);
1654 	sparse_list_clear(pax);
1655 	free(pax);
1656 	a->format_data = NULL;
1657 	return (ARCHIVE_OK);
1658 }
1659 
1660 static int
1661 archive_write_pax_finish_entry(struct archive_write *a)
1662 {
1663 	struct pax *pax;
1664 	uint64_t remaining;
1665 	int ret;
1666 
1667 	pax = (struct pax *)a->format_data;
1668 	remaining = pax->entry_bytes_remaining;
1669 	if (remaining == 0) {
1670 		while (pax->sparse_list) {
1671 			struct sparse_block *sb;
1672 			if (!pax->sparse_list->is_hole)
1673 				remaining += pax->sparse_list->remaining;
1674 			sb = pax->sparse_list->next;
1675 			free(pax->sparse_list);
1676 			pax->sparse_list = sb;
1677 		}
1678 	}
1679 	ret = __archive_write_nulls(a, (size_t)(remaining + pax->entry_padding));
1680 	pax->entry_bytes_remaining = pax->entry_padding = 0;
1681 	return (ret);
1682 }
1683 
1684 static ssize_t
1685 archive_write_pax_data(struct archive_write *a, const void *buff, size_t s)
1686 {
1687 	struct pax *pax;
1688 	size_t ws;
1689 	size_t total;
1690 	int ret;
1691 
1692 	pax = (struct pax *)a->format_data;
1693 
1694 	/*
1695 	 * According to GNU PAX format 1.0, write a sparse map
1696 	 * before the body.
1697 	 */
1698 	if (archive_strlen(&(pax->sparse_map))) {
1699 		ret = __archive_write_output(a, pax->sparse_map.s,
1700 		    archive_strlen(&(pax->sparse_map)));
1701 		if (ret != ARCHIVE_OK)
1702 			return (ret);
1703 		ret = __archive_write_nulls(a, pax->sparse_map_padding);
1704 		if (ret != ARCHIVE_OK)
1705 			return (ret);
1706 		archive_string_empty(&(pax->sparse_map));
1707 	}
1708 
1709 	total = 0;
1710 	while (total < s) {
1711 		const unsigned char *p;
1712 
1713 		while (pax->sparse_list != NULL &&
1714 		    pax->sparse_list->remaining == 0) {
1715 			struct sparse_block *sb = pax->sparse_list->next;
1716 			free(pax->sparse_list);
1717 			pax->sparse_list = sb;
1718 		}
1719 
1720 		if (pax->sparse_list == NULL)
1721 			return (total);
1722 
1723 		p = ((const unsigned char *)buff) + total;
1724 		ws = s - total;
1725 		if (ws > pax->sparse_list->remaining)
1726 			ws = (size_t)pax->sparse_list->remaining;
1727 
1728 		if (pax->sparse_list->is_hole) {
1729 			/* Current block is hole thus we do not write
1730 			 * the body. */
1731 			pax->sparse_list->remaining -= ws;
1732 			total += ws;
1733 			continue;
1734 		}
1735 
1736 		ret = __archive_write_output(a, p, ws);
1737 		pax->sparse_list->remaining -= ws;
1738 		total += ws;
1739 		if (ret != ARCHIVE_OK)
1740 			return (ret);
1741 	}
1742 	return (total);
1743 }
1744 
1745 static int
1746 has_non_ASCII(const char *_p)
1747 {
1748 	const unsigned char *p = (const unsigned char *)_p;
1749 
1750 	if (p == NULL)
1751 		return (1);
1752 	while (*p != '\0' && *p < 128)
1753 		p++;
1754 	return (*p != '\0');
1755 }
1756 
1757 /*
1758  * Used by extended attribute support; encodes the name
1759  * so that there will be no '=' characters in the result.
1760  */
1761 static char *
1762 url_encode(const char *in)
1763 {
1764 	const char *s;
1765 	char *d;
1766 	int out_len = 0;
1767 	char *out;
1768 
1769 	for (s = in; *s != '\0'; s++) {
1770 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=')
1771 			out_len += 3;
1772 		else
1773 			out_len++;
1774 	}
1775 
1776 	out = (char *)malloc(out_len + 1);
1777 	if (out == NULL)
1778 		return (NULL);
1779 
1780 	for (s = in, d = out; *s != '\0'; s++) {
1781 		/* encode any non-printable ASCII character or '%' or '=' */
1782 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=') {
1783 			/* URL encoding is '%' followed by two hex digits */
1784 			*d++ = '%';
1785 			*d++ = "0123456789ABCDEF"[0x0f & (*s >> 4)];
1786 			*d++ = "0123456789ABCDEF"[0x0f & *s];
1787 		} else {
1788 			*d++ = *s;
1789 		}
1790 	}
1791 	*d = '\0';
1792 	return (out);
1793 }
1794 
1795 /*
1796  * Encode a sequence of bytes into a C string using base-64 encoding.
1797  *
1798  * Returns a null-terminated C string allocated with malloc(); caller
1799  * is responsible for freeing the result.
1800  */
1801 static char *
1802 base64_encode(const char *s, size_t len)
1803 {
1804 	static const char digits[64] =
1805 	    { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O',
1806 	      'P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d',
1807 	      'e','f','g','h','i','j','k','l','m','n','o','p','q','r','s',
1808 	      't','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
1809 	      '8','9','+','/' };
1810 	int v;
1811 	char *d, *out;
1812 
1813 	/* 3 bytes becomes 4 chars, but round up and allow for trailing NUL */
1814 	out = (char *)malloc((len * 4 + 2) / 3 + 1);
1815 	if (out == NULL)
1816 		return (NULL);
1817 	d = out;
1818 
1819 	/* Convert each group of 3 bytes into 4 characters. */
1820 	while (len >= 3) {
1821 		v = (((int)s[0] << 16) & 0xff0000)
1822 		    | (((int)s[1] << 8) & 0xff00)
1823 		    | (((int)s[2]) & 0x00ff);
1824 		s += 3;
1825 		len -= 3;
1826 		*d++ = digits[(v >> 18) & 0x3f];
1827 		*d++ = digits[(v >> 12) & 0x3f];
1828 		*d++ = digits[(v >> 6) & 0x3f];
1829 		*d++ = digits[(v) & 0x3f];
1830 	}
1831 	/* Handle final group of 1 byte (2 chars) or 2 bytes (3 chars). */
1832 	switch (len) {
1833 	case 0: break;
1834 	case 1:
1835 		v = (((int)s[0] << 16) & 0xff0000);
1836 		*d++ = digits[(v >> 18) & 0x3f];
1837 		*d++ = digits[(v >> 12) & 0x3f];
1838 		break;
1839 	case 2:
1840 		v = (((int)s[0] << 16) & 0xff0000)
1841 		    | (((int)s[1] << 8) & 0xff00);
1842 		*d++ = digits[(v >> 18) & 0x3f];
1843 		*d++ = digits[(v >> 12) & 0x3f];
1844 		*d++ = digits[(v >> 6) & 0x3f];
1845 		break;
1846 	}
1847 	/* Add trailing NUL character so output is a valid C string. */
1848 	*d = '\0';
1849 	return (out);
1850 }
1851 
1852 static void
1853 sparse_list_clear(struct pax *pax)
1854 {
1855 	while (pax->sparse_list != NULL) {
1856 		struct sparse_block *sb = pax->sparse_list;
1857 		pax->sparse_list = sb->next;
1858 		free(sb);
1859 	}
1860 	pax->sparse_tail = NULL;
1861 }
1862 
1863 static int
1864 _sparse_list_add_block(struct pax *pax, int64_t offset, int64_t length,
1865     int is_hole)
1866 {
1867 	struct sparse_block *sb;
1868 
1869 	sb = (struct sparse_block *)malloc(sizeof(*sb));
1870 	if (sb == NULL)
1871 		return (ARCHIVE_FATAL);
1872 	sb->next = NULL;
1873 	sb->is_hole = is_hole;
1874 	sb->offset = offset;
1875 	sb->remaining = length;
1876 	if (pax->sparse_list == NULL || pax->sparse_tail == NULL)
1877 		pax->sparse_list = pax->sparse_tail = sb;
1878 	else {
1879 		pax->sparse_tail->next = sb;
1880 		pax->sparse_tail = sb;
1881 	}
1882 	return (ARCHIVE_OK);
1883 }
1884 
1885 static int
1886 sparse_list_add(struct pax *pax, int64_t offset, int64_t length)
1887 {
1888 	int64_t last_offset;
1889 	int r;
1890 
1891 	if (pax->sparse_tail == NULL)
1892 		last_offset = 0;
1893 	else {
1894 		last_offset = pax->sparse_tail->offset +
1895 		    pax->sparse_tail->remaining;
1896 	}
1897 	if (last_offset < offset) {
1898 		/* Add a hole block. */
1899 		r = _sparse_list_add_block(pax, last_offset,
1900 		    offset - last_offset, 1);
1901 		if (r != ARCHIVE_OK)
1902 			return (r);
1903 	}
1904 	/* Add data block. */
1905 	return (_sparse_list_add_block(pax, offset, length, 0));
1906 }
1907 
1908