1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "archive_platform.h"
27 __FBSDID("$FreeBSD: src/lib/libarchive/archive_write_set_format_pax.c,v 1.47 2008/05/26 17:00:23 kientzle Exp $");
28 
29 #ifdef HAVE_ERRNO_H
30 #include <errno.h>
31 #endif
32 #ifdef HAVE_STDLIB_H
33 #include <stdlib.h>
34 #endif
35 #ifdef HAVE_STRING_H
36 #include <string.h>
37 #endif
38 
39 #include "archive.h"
40 #include "archive_entry.h"
41 #include "archive_private.h"
42 #include "archive_write_private.h"
43 
44 struct pax {
45 	uint64_t	entry_bytes_remaining;
46 	uint64_t	entry_padding;
47 	struct archive_string	pax_header;
48 };
49 
50 static void		 add_pax_attr(struct archive_string *, const char *key,
51 			     const char *value);
52 static void		 add_pax_attr_int(struct archive_string *,
53 			     const char *key, int64_t value);
54 static void		 add_pax_attr_time(struct archive_string *,
55 			     const char *key, int64_t sec,
56 			     unsigned long nanos);
57 static void		 add_pax_attr_w(struct archive_string *,
58 			     const char *key, const wchar_t *wvalue);
59 static ssize_t		 archive_write_pax_data(struct archive_write *,
60 			     const void *, size_t);
61 static int		 archive_write_pax_finish(struct archive_write *);
62 static int		 archive_write_pax_destroy(struct archive_write *);
63 static int		 archive_write_pax_finish_entry(struct archive_write *);
64 static int		 archive_write_pax_header(struct archive_write *,
65 			     struct archive_entry *);
66 static char		*base64_encode(const char *src, size_t len);
67 static char		*build_pax_attribute_name(char *dest, const char *src);
68 static char		*build_ustar_entry_name(char *dest, const char *src,
69 			     size_t src_length, const char *insert);
70 static char		*format_int(char *dest, int64_t);
71 static int		 has_non_ASCII(const wchar_t *);
72 static char		*url_encode(const char *in);
73 static int		 write_nulls(struct archive_write *, size_t);
74 
75 /*
76  * Set output format to 'restricted pax' format.
77  *
78  * This is the same as normal 'pax', but tries to suppress
79  * the pax header whenever possible.  This is the default for
80  * bsdtar, for instance.
81  */
82 int
83 archive_write_set_format_pax_restricted(struct archive *_a)
84 {
85 	struct archive_write *a = (struct archive_write *)_a;
86 	int r;
87 	r = archive_write_set_format_pax(&a->archive);
88 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_RESTRICTED;
89 	a->archive.archive_format_name = "restricted POSIX pax interchange";
90 	return (r);
91 }
92 
93 /*
94  * Set output format to 'pax' format.
95  */
96 int
97 archive_write_set_format_pax(struct archive *_a)
98 {
99 	struct archive_write *a = (struct archive_write *)_a;
100 	struct pax *pax;
101 
102 	if (a->format_destroy != NULL)
103 		(a->format_destroy)(a);
104 
105 	pax = (struct pax *)malloc(sizeof(*pax));
106 	if (pax == NULL) {
107 		archive_set_error(&a->archive, ENOMEM, "Can't allocate pax data");
108 		return (ARCHIVE_FATAL);
109 	}
110 	memset(pax, 0, sizeof(*pax));
111 	a->format_data = pax;
112 
113 	a->pad_uncompressed = 1;
114 	a->format_write_header = archive_write_pax_header;
115 	a->format_write_data = archive_write_pax_data;
116 	a->format_finish = archive_write_pax_finish;
117 	a->format_destroy = archive_write_pax_destroy;
118 	a->format_finish_entry = archive_write_pax_finish_entry;
119 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
120 	a->archive.archive_format_name = "POSIX pax interchange";
121 	return (ARCHIVE_OK);
122 }
123 
124 /*
125  * Note: This code assumes that 'nanos' has the same sign as 'sec',
126  * which implies that sec=-1, nanos=200000000 represents -1.2 seconds
127  * and not -0.8 seconds.  This is a pretty pedantic point, as we're
128  * unlikely to encounter many real files created before Jan 1, 1970,
129  * much less ones with timestamps recorded to sub-second resolution.
130  */
131 static void
132 add_pax_attr_time(struct archive_string *as, const char *key,
133     int64_t sec, unsigned long nanos)
134 {
135 	int digit, i;
136 	char *t;
137 	/*
138 	 * Note that each byte contributes fewer than 3 base-10
139 	 * digits, so this will always be big enough.
140 	 */
141 	char tmp[1 + 3*sizeof(sec) + 1 + 3*sizeof(nanos)];
142 
143 	tmp[sizeof(tmp) - 1] = 0;
144 	t = tmp + sizeof(tmp) - 1;
145 
146 	/* Skip trailing zeros in the fractional part. */
147 	for (digit = 0, i = 10; i > 0 && digit == 0; i--) {
148 		digit = nanos % 10;
149 		nanos /= 10;
150 	}
151 
152 	/* Only format the fraction if it's non-zero. */
153 	if (i > 0) {
154 		while (i > 0) {
155 			*--t = "0123456789"[digit];
156 			digit = nanos % 10;
157 			nanos /= 10;
158 			i--;
159 		}
160 		*--t = '.';
161 	}
162 	t = format_int(t, sec);
163 
164 	add_pax_attr(as, key, t);
165 }
166 
167 static char *
168 format_int(char *t, int64_t i)
169 {
170 	int sign;
171 
172 	if (i < 0) {
173 		sign = -1;
174 		i = -i;
175 	} else
176 		sign = 1;
177 
178 	do {
179 		*--t = "0123456789"[i % 10];
180 	} while (i /= 10);
181 	if (sign < 0)
182 		*--t = '-';
183 	return (t);
184 }
185 
186 static void
187 add_pax_attr_int(struct archive_string *as, const char *key, int64_t value)
188 {
189 	char tmp[1 + 3 * sizeof(value)];
190 
191 	tmp[sizeof(tmp) - 1] = 0;
192 	add_pax_attr(as, key, format_int(tmp + sizeof(tmp) - 1, value));
193 }
194 
195 static char *
196 utf8_encode(const wchar_t *wval)
197 {
198 	int utf8len;
199 	const wchar_t *wp;
200 	unsigned long wc;
201 	char *utf8_value, *p;
202 
203 	utf8len = 0;
204 	for (wp = wval; *wp != L'\0'; ) {
205 		wc = *wp++;
206 		if (wc <= 0x7f)
207 			utf8len++;
208 		else if (wc <= 0x7ff)
209 			utf8len += 2;
210 		else if (wc <= 0xffff)
211 			utf8len += 3;
212 		else if (wc <= 0x1fffff)
213 			utf8len += 4;
214 		else if (wc <= 0x3ffffff)
215 			utf8len += 5;
216 		else if (wc <= 0x7fffffff)
217 			utf8len += 6;
218 		/* Ignore larger values; UTF-8 can't encode them. */
219 	}
220 
221 	utf8_value = (char *)malloc(utf8len + 1);
222 	if (utf8_value == NULL) {
223 		__archive_errx(1, "Not enough memory for attributes");
224 		return (NULL);
225 	}
226 
227 	for (wp = wval, p = utf8_value; *wp != L'\0'; ) {
228 		wc = *wp++;
229 		if (wc <= 0x7f) {
230 			*p++ = (char)wc;
231 		} else if (wc <= 0x7ff) {
232 			p[0] = 0xc0 | ((wc >> 6) & 0x1f);
233 			p[1] = 0x80 | (wc & 0x3f);
234 			p += 2;
235 		} else if (wc <= 0xffff) {
236 			p[0] = 0xe0 | ((wc >> 12) & 0x0f);
237 			p[1] = 0x80 | ((wc >> 6) & 0x3f);
238 			p[2] = 0x80 | (wc & 0x3f);
239 			p += 3;
240 		} else if (wc <= 0x1fffff) {
241 			p[0] = 0xf0 | ((wc >> 18) & 0x07);
242 			p[1] = 0x80 | ((wc >> 12) & 0x3f);
243 			p[2] = 0x80 | ((wc >> 6) & 0x3f);
244 			p[3] = 0x80 | (wc & 0x3f);
245 			p += 4;
246 		} else if (wc <= 0x3ffffff) {
247 			p[0] = 0xf8 | ((wc >> 24) & 0x03);
248 			p[1] = 0x80 | ((wc >> 18) & 0x3f);
249 			p[2] = 0x80 | ((wc >> 12) & 0x3f);
250 			p[3] = 0x80 | ((wc >> 6) & 0x3f);
251 			p[4] = 0x80 | (wc & 0x3f);
252 			p += 5;
253 		} else if (wc <= 0x7fffffff) {
254 			p[0] = 0xfc | ((wc >> 30) & 0x01);
255 			p[1] = 0x80 | ((wc >> 24) & 0x3f);
256 			p[1] = 0x80 | ((wc >> 18) & 0x3f);
257 			p[2] = 0x80 | ((wc >> 12) & 0x3f);
258 			p[3] = 0x80 | ((wc >> 6) & 0x3f);
259 			p[4] = 0x80 | (wc & 0x3f);
260 			p += 6;
261 		}
262 		/* Ignore larger values; UTF-8 can't encode them. */
263 	}
264 	*p = '\0';
265 
266 	return (utf8_value);
267 }
268 
269 static void
270 add_pax_attr_w(struct archive_string *as, const char *key, const wchar_t *wval)
271 {
272 	char *utf8_value = utf8_encode(wval);
273 	if (utf8_value == NULL)
274 		return;
275 	add_pax_attr(as, key, utf8_value);
276 	free(utf8_value);
277 }
278 
279 /*
280  * Add a key/value attribute to the pax header.  This function handles
281  * the length field and various other syntactic requirements.
282  */
283 static void
284 add_pax_attr(struct archive_string *as, const char *key, const char *value)
285 {
286 	int digits, i, len, next_ten;
287 	char tmp[1 + 3 * sizeof(int)];	/* < 3 base-10 digits per byte */
288 
289 	/*-
290 	 * PAX attributes have the following layout:
291 	 *     <len> <space> <key> <=> <value> <nl>
292 	 */
293 	len = 1 + strlen(key) + 1 + strlen(value) + 1;
294 
295 	/*
296 	 * The <len> field includes the length of the <len> field, so
297 	 * computing the correct length is tricky.  I start by
298 	 * counting the number of base-10 digits in 'len' and
299 	 * computing the next higher power of 10.
300 	 */
301 	next_ten = 1;
302 	digits = 0;
303 	i = len;
304 	while (i > 0) {
305 		i = i / 10;
306 		digits++;
307 		next_ten = next_ten * 10;
308 	}
309 	/*
310 	 * For example, if string without the length field is 99
311 	 * chars, then adding the 2 digit length "99" will force the
312 	 * total length past 100, requiring an extra digit.  The next
313 	 * statement adjusts for this effect.
314 	 */
315 	if (len + digits >= next_ten)
316 		digits++;
317 
318 	/* Now, we have the right length so we can build the line. */
319 	tmp[sizeof(tmp) - 1] = 0;	/* Null-terminate the work area. */
320 	archive_strcat(as, format_int(tmp + sizeof(tmp) - 1, len + digits));
321 	archive_strappend_char(as, ' ');
322 	archive_strcat(as, key);
323 	archive_strappend_char(as, '=');
324 	archive_strcat(as, value);
325 	archive_strappend_char(as, '\n');
326 }
327 
328 static void
329 archive_write_pax_header_xattrs(struct pax *pax, struct archive_entry *entry)
330 {
331 	struct archive_string s;
332 	int i = archive_entry_xattr_reset(entry);
333 
334 	while (i--) {
335 		const char *name;
336 		const void *value;
337 		char *encoded_value;
338 		char *url_encoded_name = NULL, *encoded_name = NULL;
339 		wchar_t *wcs_name = NULL;
340 		size_t size;
341 
342 		archive_entry_xattr_next(entry, &name, &value, &size);
343 		/* Name is URL-encoded, then converted to wchar_t,
344 		 * then UTF-8 encoded. */
345 		url_encoded_name = url_encode(name);
346 		if (url_encoded_name != NULL) {
347 			/* Convert narrow-character to wide-character. */
348 			int wcs_length = strlen(url_encoded_name);
349 			wcs_name = (wchar_t *)malloc((wcs_length + 1) * sizeof(wchar_t));
350 			if (wcs_name == NULL)
351 				__archive_errx(1, "No memory for xattr conversion");
352 			mbstowcs(wcs_name, url_encoded_name, wcs_length);
353 			wcs_name[wcs_length] = 0;
354 			free(url_encoded_name); /* Done with this. */
355 		}
356 		if (wcs_name != NULL) {
357 			encoded_name = utf8_encode(wcs_name);
358 			free(wcs_name); /* Done with wchar_t name. */
359 		}
360 
361 		encoded_value = base64_encode((const char *)value, size);
362 
363 		if (encoded_name != NULL && encoded_value != NULL) {
364 			archive_string_init(&s);
365 			archive_strcpy(&s, "LIBARCHIVE.xattr.");
366 			archive_strcat(&s, encoded_name);
367 			add_pax_attr(&(pax->pax_header), s.s, encoded_value);
368 			archive_string_free(&s);
369 		}
370 		free(encoded_name);
371 		free(encoded_value);
372 	}
373 }
374 
375 /*
376  * TODO: Consider adding 'comment' and 'charset' fields to
377  * archive_entry so that clients can specify them.  Also, consider
378  * adding generic key/value tags so clients can add arbitrary
379  * key/value data.
380  */
381 static int
382 archive_write_pax_header(struct archive_write *a,
383     struct archive_entry *entry_original)
384 {
385 	struct archive_entry *entry_main;
386 	const char *p;
387 	char *t;
388 	const wchar_t *wp;
389 	const char *suffix;
390 	int need_extension, r, ret;
391 	struct pax *pax;
392 	const char *hdrcharset = NULL;
393 	const char *hardlink;
394 	const char *path = NULL, *linkpath = NULL;
395 	const char *uname = NULL, *gname = NULL;
396 	const wchar_t *path_w = NULL, *linkpath_w = NULL;
397 	const wchar_t *uname_w = NULL, *gname_w = NULL;
398 
399 	char paxbuff[512];
400 	char ustarbuff[512];
401 	char ustar_entry_name[256];
402 	char pax_entry_name[256];
403 
404 	ret = ARCHIVE_OK;
405 	need_extension = 0;
406 	pax = (struct pax *)a->format_data;
407 
408 	hardlink = archive_entry_hardlink(entry_original);
409 
410 	/* Make sure this is a type of entry that we can handle here */
411 	if (hardlink == NULL) {
412 		switch (archive_entry_filetype(entry_original)) {
413 		case AE_IFBLK:
414 		case AE_IFCHR:
415 		case AE_IFIFO:
416 		case AE_IFLNK:
417 		case AE_IFREG:
418 			break;
419 		case AE_IFDIR:
420 			/*
421 			 * Ensure a trailing '/'.  Modify the original
422 			 * entry so the client sees the change.
423 			 */
424 			p = archive_entry_pathname(entry_original);
425 			if (p[strlen(p) - 1] != '/') {
426 				t = (char *)malloc(strlen(p) + 2);
427 				if (t == NULL) {
428 					archive_set_error(&a->archive, ENOMEM,
429 					"Can't allocate pax data");
430 					return(ARCHIVE_FATAL);
431 				}
432 				strcpy(t, p);
433 				strcat(t, "/");
434 				archive_entry_copy_pathname(entry_original, t);
435 				free(t);
436 			}
437 			break;
438 		default:
439 			archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
440 			    "tar format cannot archive this (type=0%lo)",
441 			    (unsigned long)archive_entry_filetype(entry_original));
442 			return (ARCHIVE_WARN);
443 		}
444 	}
445 
446 	/* Copy entry so we can modify it as needed. */
447 	entry_main = archive_entry_clone(entry_original);
448 	archive_string_empty(&(pax->pax_header)); /* Blank our work area. */
449 
450 	/*
451 	 * First, check the name fields and see if any of them
452 	 * require binary coding.  If any of them does, then all of
453 	 * them do.
454 	 */
455 	hdrcharset = NULL;
456 	path = archive_entry_pathname(entry_main);
457 	path_w = archive_entry_pathname_w(entry_main);
458 	if (path != NULL && path_w == NULL) {
459 		archive_set_error(&a->archive, EILSEQ,
460 		    "Can't translate pathname '%s' to UTF-8", path);
461 		ret = ARCHIVE_WARN;
462 		hdrcharset = "BINARY";
463 	}
464 	uname = archive_entry_uname(entry_main);
465 	uname_w = archive_entry_uname_w(entry_main);
466 	if (uname != NULL && uname_w == NULL) {
467 		archive_set_error(&a->archive, EILSEQ,
468 		    "Can't translate uname '%s' to UTF-8", uname);
469 		ret = ARCHIVE_WARN;
470 		hdrcharset = "BINARY";
471 	}
472 	gname = archive_entry_gname(entry_main);
473 	gname_w = archive_entry_gname_w(entry_main);
474 	if (gname != NULL && gname_w == NULL) {
475 		archive_set_error(&a->archive, EILSEQ,
476 		    "Can't translate gname '%s' to UTF-8", gname);
477 		ret = ARCHIVE_WARN;
478 		hdrcharset = "BINARY";
479 	}
480 	linkpath = hardlink;
481 	if (linkpath != NULL) {
482 		linkpath_w = archive_entry_hardlink_w(entry_main);
483 	} else {
484 		linkpath = archive_entry_symlink(entry_main);
485 		if (linkpath != NULL)
486 			linkpath_w = archive_entry_symlink_w(entry_main);
487 	}
488 	if (linkpath != NULL && linkpath_w == NULL) {
489 		archive_set_error(&a->archive, EILSEQ,
490 		    "Can't translate linkpath '%s' to UTF-8", linkpath);
491 		ret = ARCHIVE_WARN;
492 		hdrcharset = "BINARY";
493 	}
494 
495 	/* Store the header encoding first, to be nice to readers. */
496 	if (hdrcharset != NULL)
497 		add_pax_attr(&(pax->pax_header), "hdrcharset", hdrcharset);
498 
499 
500 	/*
501 	 * If name is too long, or has non-ASCII characters, add
502 	 * 'path' to pax extended attrs.  (Note that an unconvertible
503 	 * name must have non-ASCII characters.)
504 	 */
505 	if (path == NULL) {
506 		/* We don't have a narrow version, so we have to store
507 		 * the wide version. */
508 		add_pax_attr_w(&(pax->pax_header), "path", path_w);
509 		archive_entry_set_pathname(entry_main, "@WidePath");
510 		need_extension = 1;
511 	} else if (has_non_ASCII(path_w)) {
512 		/* We have non-ASCII characters. */
513 		if (path_w == NULL || hdrcharset != NULL) {
514 			/* Can't do UTF-8, so store it raw. */
515 			add_pax_attr(&(pax->pax_header), "path", path);
516 		} else {
517 			/* Store UTF-8 */
518 			add_pax_attr_w(&(pax->pax_header),
519 			    "path", path_w);
520 		}
521 		archive_entry_set_pathname(entry_main,
522 		    build_ustar_entry_name(ustar_entry_name,
523 			path, strlen(path), NULL));
524 		need_extension = 1;
525 	} else {
526 		/* We have an all-ASCII path; we'd like to just store
527 		 * it in the ustar header if it will fit.  Yes, this
528 		 * duplicates some of the logic in
529 		 * write_set_format_ustar.c
530 		 */
531 		if (strlen(path) <= 100) {
532 			/* Fits in the old 100-char tar name field. */
533 		} else {
534 			/* Find largest suffix that will fit. */
535 			/* Note: strlen() > 100, so strlen() - 100 - 1 >= 0 */
536 			suffix = strchr(path + strlen(path) - 100 - 1, '/');
537 			/* Don't attempt an empty prefix. */
538 			if (suffix == path)
539 				suffix = strchr(suffix + 1, '/');
540 			/* We can put it in the ustar header if it's
541 			 * all ASCII and it's either <= 100 characters
542 			 * or can be split at a '/' into a prefix <=
543 			 * 155 chars and a suffix <= 100 chars.  (Note
544 			 * the strchr() above will return NULL exactly
545 			 * when the path can't be split.)
546 			 */
547 			if (suffix == NULL       /* Suffix > 100 chars. */
548 			    || suffix[1] == '\0'    /* empty suffix */
549 			    || suffix - path > 155)  /* Prefix > 155 chars */
550 			{
551 				if (path_w == NULL || hdrcharset != NULL) {
552 					/* Can't do UTF-8, so store it raw. */
553 					add_pax_attr(&(pax->pax_header),
554 					    "path", path);
555 				} else {
556 					/* Store UTF-8 */
557 					add_pax_attr_w(&(pax->pax_header),
558 					    "path", path_w);
559 				}
560 				archive_entry_set_pathname(entry_main,
561 				    build_ustar_entry_name(ustar_entry_name,
562 					path, strlen(path), NULL));
563 				need_extension = 1;
564 			}
565 		}
566 	}
567 
568 	if (linkpath != NULL) {
569 		/* If link name is too long or has non-ASCII characters, add
570 		 * 'linkpath' to pax extended attrs. */
571 		if (strlen(linkpath) > 100 || linkpath_w == NULL
572 		    || linkpath_w == NULL || has_non_ASCII(linkpath_w)) {
573 			if (linkpath_w == NULL || hdrcharset != NULL)
574 				/* If the linkpath is not convertible
575 				 * to wide, or we're encoding in
576 				 * binary anyway, store it raw. */
577 				add_pax_attr(&(pax->pax_header),
578 				    "linkpath", linkpath);
579 			else
580 				/* If the link is long or has a
581 				 * non-ASCII character, store it as a
582 				 * pax extended attribute. */
583 				add_pax_attr_w(&(pax->pax_header),
584 				    "linkpath", linkpath_w);
585 			if (strlen(linkpath) > 100) {
586 				if (hardlink != NULL)
587 					archive_entry_set_hardlink(entry_main,
588 					    "././@LongHardLink");
589 				else
590 					archive_entry_set_symlink(entry_main,
591 					    "././@LongSymLink");
592 			}
593 			need_extension = 1;
594 		}
595 	}
596 
597 	/* If file size is too large, add 'size' to pax extended attrs. */
598 	if (archive_entry_size(entry_main) >= (((int64_t)1) << 33)) {
599 		add_pax_attr_int(&(pax->pax_header), "size",
600 		    archive_entry_size(entry_main));
601 		need_extension = 1;
602 	}
603 
604 	/* If numeric GID is too large, add 'gid' to pax extended attrs. */
605 	if (archive_entry_gid(entry_main) >= (1 << 18)) {
606 		add_pax_attr_int(&(pax->pax_header), "gid",
607 		    archive_entry_gid(entry_main));
608 		need_extension = 1;
609 	}
610 
611 	/* If group name is too large or has non-ASCII characters, add
612 	 * 'gname' to pax extended attrs. */
613 	if (gname != NULL) {
614 		if (strlen(gname) > 31
615 		    || gname_w == NULL
616 		    || has_non_ASCII(gname_w))
617 		{
618 			if (gname_w == NULL || hdrcharset != NULL) {
619 				add_pax_attr(&(pax->pax_header),
620 				    "gname", gname);
621 			} else  {
622 				add_pax_attr_w(&(pax->pax_header),
623 				    "gname", gname_w);
624 			}
625 			need_extension = 1;
626 		}
627 	}
628 
629 	/* If numeric UID is too large, add 'uid' to pax extended attrs. */
630 	if (archive_entry_uid(entry_main) >= (1 << 18)) {
631 		add_pax_attr_int(&(pax->pax_header), "uid",
632 		    archive_entry_uid(entry_main));
633 		need_extension = 1;
634 	}
635 
636 	/* Add 'uname' to pax extended attrs if necessary. */
637 	if (uname != NULL) {
638 		if (strlen(uname) > 31
639 		    || uname_w == NULL
640 		    || has_non_ASCII(uname_w))
641 		{
642 			if (uname_w == NULL || hdrcharset != NULL) {
643 				add_pax_attr(&(pax->pax_header),
644 				    "uname", uname);
645 			} else {
646 				add_pax_attr_w(&(pax->pax_header),
647 				    "uname", uname_w);
648 			}
649 			need_extension = 1;
650 		}
651 	}
652 
653 	/*
654 	 * POSIX/SUSv3 doesn't provide a standard key for large device
655 	 * numbers.  I use the same keys here that Joerg Schilling
656 	 * used for 'star.'  (Which, somewhat confusingly, are called
657 	 * "devXXX" even though they code "rdev" values.)  No doubt,
658 	 * other implementations use other keys.  Note that there's no
659 	 * reason we can't write the same information into a number of
660 	 * different keys.
661 	 *
662 	 * Of course, this is only needed for block or char device entries.
663 	 */
664 	if (archive_entry_filetype(entry_main) == AE_IFBLK
665 	    || archive_entry_filetype(entry_main) == AE_IFCHR) {
666 		/*
667 		 * If rdevmajor is too large, add 'SCHILY.devmajor' to
668 		 * extended attributes.
669 		 */
670 		dev_t rdevmajor, rdevminor;
671 		rdevmajor = archive_entry_rdevmajor(entry_main);
672 		rdevminor = archive_entry_rdevminor(entry_main);
673 		if (rdevmajor >= (1 << 18)) {
674 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devmajor",
675 			    rdevmajor);
676 			/*
677 			 * Non-strict formatting below means we don't
678 			 * have to truncate here.  Not truncating improves
679 			 * the chance that some more modern tar archivers
680 			 * (such as GNU tar 1.13) can restore the full
681 			 * value even if they don't understand the pax
682 			 * extended attributes.  See my rant below about
683 			 * file size fields for additional details.
684 			 */
685 			/* archive_entry_set_rdevmajor(entry_main,
686 			   rdevmajor & ((1 << 18) - 1)); */
687 			need_extension = 1;
688 		}
689 
690 		/*
691 		 * If devminor is too large, add 'SCHILY.devminor' to
692 		 * extended attributes.
693 		 */
694 		if (rdevminor >= (1 << 18)) {
695 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devminor",
696 			    rdevminor);
697 			/* Truncation is not necessary here, either. */
698 			/* archive_entry_set_rdevminor(entry_main,
699 			   rdevminor & ((1 << 18) - 1)); */
700 			need_extension = 1;
701 		}
702 	}
703 
704 	/*
705 	 * Technically, the mtime field in the ustar header can
706 	 * support 33 bits, but many platforms use signed 32-bit time
707 	 * values.  The cutoff of 0x7fffffff here is a compromise.
708 	 * Yes, this check is duplicated just below; this helps to
709 	 * avoid writing an mtime attribute just to handle a
710 	 * high-resolution timestamp in "restricted pax" mode.
711 	 */
712 	if (!need_extension &&
713 	    ((archive_entry_mtime(entry_main) < 0)
714 		|| (archive_entry_mtime(entry_main) >= 0x7fffffff)))
715 		need_extension = 1;
716 
717 	/* I use a star-compatible file flag attribute. */
718 	p = archive_entry_fflags_text(entry_main);
719 	if (!need_extension && p != NULL  &&  *p != '\0')
720 		need_extension = 1;
721 
722 	/* If there are non-trivial ACL entries, we need an extension. */
723 	if (!need_extension && archive_entry_acl_count(entry_original,
724 		ARCHIVE_ENTRY_ACL_TYPE_ACCESS) > 0)
725 		need_extension = 1;
726 
727 	/* If there are non-trivial ACL entries, we need an extension. */
728 	if (!need_extension && archive_entry_acl_count(entry_original,
729 		ARCHIVE_ENTRY_ACL_TYPE_DEFAULT) > 0)
730 		need_extension = 1;
731 
732 	/* If there are extended attributes, we need an extension */
733 	if (!need_extension && archive_entry_xattr_count(entry_original) > 0)
734 		need_extension = 1;
735 
736 	/*
737 	 * The following items are handled differently in "pax
738 	 * restricted" format.  In particular, in "pax restricted"
739 	 * format they won't be added unless need_extension is
740 	 * already set (we're already generating an extended header, so
741 	 * may as well include these).
742 	 */
743 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED ||
744 	    need_extension) {
745 
746 		if (archive_entry_mtime(entry_main) < 0  ||
747 		    archive_entry_mtime(entry_main) >= 0x7fffffff  ||
748 		    archive_entry_mtime_nsec(entry_main) != 0)
749 			add_pax_attr_time(&(pax->pax_header), "mtime",
750 			    archive_entry_mtime(entry_main),
751 			    archive_entry_mtime_nsec(entry_main));
752 
753 		if (archive_entry_ctime(entry_main) != 0  ||
754 		    archive_entry_ctime_nsec(entry_main) != 0)
755 			add_pax_attr_time(&(pax->pax_header), "ctime",
756 			    archive_entry_ctime(entry_main),
757 			    archive_entry_ctime_nsec(entry_main));
758 
759 		if (archive_entry_atime(entry_main) != 0 ||
760 		    archive_entry_atime_nsec(entry_main) != 0)
761 			add_pax_attr_time(&(pax->pax_header), "atime",
762 			    archive_entry_atime(entry_main),
763 			    archive_entry_atime_nsec(entry_main));
764 
765 		/* I use a star-compatible file flag attribute. */
766 		p = archive_entry_fflags_text(entry_main);
767 		if (p != NULL  &&  *p != '\0')
768 			add_pax_attr(&(pax->pax_header), "SCHILY.fflags", p);
769 
770 		/* I use star-compatible ACL attributes. */
771 		wp = archive_entry_acl_text_w(entry_original,
772 		    ARCHIVE_ENTRY_ACL_TYPE_ACCESS |
773 		    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID);
774 		if (wp != NULL && *wp != L'\0')
775 			add_pax_attr_w(&(pax->pax_header),
776 			    "SCHILY.acl.access", wp);
777 		wp = archive_entry_acl_text_w(entry_original,
778 		    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT |
779 		    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID);
780 		if (wp != NULL && *wp != L'\0')
781 			add_pax_attr_w(&(pax->pax_header),
782 			    "SCHILY.acl.default", wp);
783 
784 		/* Include star-compatible metadata info. */
785 		/* Note: "SCHILY.dev{major,minor}" are NOT the
786 		 * major/minor portions of "SCHILY.dev". */
787 		add_pax_attr_int(&(pax->pax_header), "SCHILY.dev",
788 		    archive_entry_dev(entry_main));
789 		add_pax_attr_int(&(pax->pax_header), "SCHILY.ino",
790 		    archive_entry_ino(entry_main));
791 		add_pax_attr_int(&(pax->pax_header), "SCHILY.nlink",
792 		    archive_entry_nlink(entry_main));
793 
794 		/* Store extended attributes */
795 		archive_write_pax_header_xattrs(pax, entry_original);
796 	}
797 
798 	/* Only regular files have data. */
799 	if (archive_entry_filetype(entry_main) != AE_IFREG)
800 		archive_entry_set_size(entry_main, 0);
801 
802 	/*
803 	 * Pax-restricted does not store data for hardlinks, in order
804 	 * to improve compatibility with ustar.
805 	 */
806 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE &&
807 	    hardlink != NULL)
808 		archive_entry_set_size(entry_main, 0);
809 
810 	/*
811 	 * XXX Full pax interchange format does permit a hardlink
812 	 * entry to have data associated with it.  I'm not supporting
813 	 * that here because the client expects me to tell them whether
814 	 * or not this format expects data for hardlinks.  If I
815 	 * don't check here, then every pax archive will end up with
816 	 * duplicated data for hardlinks.  Someday, there may be
817 	 * need to select this behavior, in which case the following
818 	 * will need to be revisited. XXX
819 	 */
820 	if (hardlink != NULL)
821 		archive_entry_set_size(entry_main, 0);
822 
823 	/* Format 'ustar' header for main entry.
824 	 *
825 	 * The trouble with file size: If the reader can't understand
826 	 * the file size, they may not be able to locate the next
827 	 * entry and the rest of the archive is toast.  Pax-compliant
828 	 * readers are supposed to ignore the file size in the main
829 	 * header, so the question becomes how to maximize portability
830 	 * for readers that don't support pax attribute extensions.
831 	 * For maximum compatibility, I permit numeric extensions in
832 	 * the main header so that the file size stored will always be
833 	 * correct, even if it's in a format that only some
834 	 * implementations understand.  The technique used here is:
835 	 *
836 	 *  a) If possible, follow the standard exactly.  This handles
837 	 *  files up to 8 gigabytes minus 1.
838 	 *
839 	 *  b) If that fails, try octal but omit the field terminator.
840 	 *  That handles files up to 64 gigabytes minus 1.
841 	 *
842 	 *  c) Otherwise, use base-256 extensions.  That handles files
843 	 *  up to 2^63 in this implementation, with the potential to
844 	 *  go up to 2^94.  That should hold us for a while. ;-)
845 	 *
846 	 * The non-strict formatter uses similar logic for other
847 	 * numeric fields, though they're less critical.
848 	 */
849 	__archive_write_format_header_ustar(a, ustarbuff, entry_main, -1, 0);
850 
851 	/* If we built any extended attributes, write that entry first. */
852 	if (archive_strlen(&(pax->pax_header)) > 0) {
853 		struct archive_entry *pax_attr_entry;
854 		time_t s;
855 		uid_t uid;
856 		gid_t gid;
857 		mode_t mode;
858 		long ns;
859 
860 		pax_attr_entry = archive_entry_new();
861 		p = archive_entry_pathname(entry_main);
862 		archive_entry_set_pathname(pax_attr_entry,
863 		    build_pax_attribute_name(pax_entry_name, p));
864 		archive_entry_set_size(pax_attr_entry,
865 		    archive_strlen(&(pax->pax_header)));
866 		/* Copy uid/gid (but clip to ustar limits). */
867 		uid = archive_entry_uid(entry_main);
868 		if (uid >= 1 << 18)
869 			uid = (1 << 18) - 1;
870 		archive_entry_set_uid(pax_attr_entry, uid);
871 		gid = archive_entry_gid(entry_main);
872 		if (gid >= 1 << 18)
873 			gid = (1 << 18) - 1;
874 		archive_entry_set_gid(pax_attr_entry, gid);
875 		/* Copy mode over (but not setuid/setgid bits) */
876 		mode = archive_entry_mode(entry_main);
877 #ifdef S_ISUID
878 		mode &= ~S_ISUID;
879 #endif
880 #ifdef S_ISGID
881 		mode &= ~S_ISGID;
882 #endif
883 #ifdef S_ISVTX
884 		mode &= ~S_ISVTX;
885 #endif
886 		archive_entry_set_mode(pax_attr_entry, mode);
887 
888 		/* Copy uname/gname. */
889 		archive_entry_set_uname(pax_attr_entry,
890 		    archive_entry_uname(entry_main));
891 		archive_entry_set_gname(pax_attr_entry,
892 		    archive_entry_gname(entry_main));
893 
894 		/* Copy mtime, but clip to ustar limits. */
895 		s = archive_entry_mtime(entry_main);
896 		ns = archive_entry_mtime_nsec(entry_main);
897 		if (s < 0) { s = 0; ns = 0; }
898 		if (s > 0x7fffffff) { s = 0x7fffffff; ns = 0; }
899 		archive_entry_set_mtime(pax_attr_entry, s, ns);
900 
901 		/* Ditto for atime. */
902 		s = archive_entry_atime(entry_main);
903 		ns = archive_entry_atime_nsec(entry_main);
904 		if (s < 0) { s = 0; ns = 0; }
905 		if (s > 0x7fffffff) { s = 0x7fffffff; ns = 0; }
906 		archive_entry_set_atime(pax_attr_entry, s, ns);
907 
908 		/* Standard ustar doesn't support ctime. */
909 		archive_entry_set_ctime(pax_attr_entry, 0, 0);
910 
911 		r = __archive_write_format_header_ustar(a, paxbuff,
912 		    pax_attr_entry, 'x', 1);
913 
914 		archive_entry_free(pax_attr_entry);
915 
916 		/* Note that the 'x' header shouldn't ever fail to format */
917 		if (r != 0) {
918 			const char *msg = "archive_write_pax_header: "
919 			    "'x' header failed?!  This can't happen.\n";
920 			write(2, msg, strlen(msg));
921 			exit(1);
922 		}
923 		r = (a->compressor.write)(a, paxbuff, 512);
924 		if (r != ARCHIVE_OK) {
925 			pax->entry_bytes_remaining = 0;
926 			pax->entry_padding = 0;
927 			return (ARCHIVE_FATAL);
928 		}
929 
930 		pax->entry_bytes_remaining = archive_strlen(&(pax->pax_header));
931 		pax->entry_padding = 0x1ff & (-(int64_t)pax->entry_bytes_remaining);
932 
933 		r = (a->compressor.write)(a, pax->pax_header.s,
934 		    archive_strlen(&(pax->pax_header)));
935 		if (r != ARCHIVE_OK) {
936 			/* If a write fails, we're pretty much toast. */
937 			return (ARCHIVE_FATAL);
938 		}
939 		/* Pad out the end of the entry. */
940 		r = write_nulls(a, pax->entry_padding);
941 		if (r != ARCHIVE_OK) {
942 			/* If a write fails, we're pretty much toast. */
943 			return (ARCHIVE_FATAL);
944 		}
945 		pax->entry_bytes_remaining = pax->entry_padding = 0;
946 	}
947 
948 	/* Write the header for main entry. */
949 	r = (a->compressor.write)(a, ustarbuff, 512);
950 	if (r != ARCHIVE_OK)
951 		return (r);
952 
953 	/*
954 	 * Inform the client of the on-disk size we're using, so
955 	 * they can avoid unnecessarily writing a body for something
956 	 * that we're just going to ignore.
957 	 */
958 	archive_entry_set_size(entry_original, archive_entry_size(entry_main));
959 	pax->entry_bytes_remaining = archive_entry_size(entry_main);
960 	pax->entry_padding = 0x1ff & (-(int64_t)pax->entry_bytes_remaining);
961 	archive_entry_free(entry_main);
962 
963 	return (ret);
964 }
965 
966 /*
967  * We need a valid name for the regular 'ustar' entry.  This routine
968  * tries to hack something more-or-less reasonable.
969  *
970  * The approach here tries to preserve leading dir names.  We do so by
971  * working with four sections:
972  *   1) "prefix" directory names,
973  *   2) "suffix" directory names,
974  *   3) inserted dir name (optional),
975  *   4) filename.
976  *
977  * These sections must satisfy the following requirements:
978  *   * Parts 1 & 2 together form an initial portion of the dir name.
979  *   * Part 3 is specified by the caller.  (It should not contain a leading
980  *     or trailing '/'.)
981  *   * Part 4 forms an initial portion of the base filename.
982  *   * The filename must be <= 99 chars to fit the ustar 'name' field.
983  *   * Parts 2, 3, 4 together must be <= 99 chars to fit the ustar 'name' fld.
984  *   * Part 1 must be <= 155 chars to fit the ustar 'prefix' field.
985  *   * If the original name ends in a '/', the new name must also end in a '/'
986  *   * Trailing '/.' sequences may be stripped.
987  *
988  * Note: Recall that the ustar format does not store the '/' separating
989  * parts 1 & 2, but does store the '/' separating parts 2 & 3.
990  */
991 static char *
992 build_ustar_entry_name(char *dest, const char *src, size_t src_length,
993     const char *insert)
994 {
995 	const char *prefix, *prefix_end;
996 	const char *suffix, *suffix_end;
997 	const char *filename, *filename_end;
998 	char *p;
999 	int need_slash = 0; /* Was there a trailing slash? */
1000 	size_t suffix_length = 99;
1001 	int insert_length;
1002 
1003 	/* Length of additional dir element to be added. */
1004 	if (insert == NULL)
1005 		insert_length = 0;
1006 	else
1007 		/* +2 here allows for '/' before and after the insert. */
1008 		insert_length = strlen(insert) + 2;
1009 
1010 	/* Step 0: Quick bailout in a common case. */
1011 	if (src_length < 100 && insert == NULL) {
1012 		strncpy(dest, src, src_length);
1013 		dest[src_length] = '\0';
1014 		return (dest);
1015 	}
1016 
1017 	/* Step 1: Locate filename and enforce the length restriction. */
1018 	filename_end = src + src_length;
1019 	/* Remove trailing '/' chars and '/.' pairs. */
1020 	for (;;) {
1021 		if (filename_end > src && filename_end[-1] == '/') {
1022 			filename_end --;
1023 			need_slash = 1; /* Remember to restore trailing '/'. */
1024 			continue;
1025 		}
1026 		if (filename_end > src + 1 && filename_end[-1] == '.'
1027 		    && filename_end[-2] == '/') {
1028 			filename_end -= 2;
1029 			need_slash = 1; /* "foo/." will become "foo/" */
1030 			continue;
1031 		}
1032 		break;
1033 	}
1034 	if (need_slash)
1035 		suffix_length--;
1036 	/* Find start of filename. */
1037 	filename = filename_end - 1;
1038 	while ((filename > src) && (*filename != '/'))
1039 		filename --;
1040 	if ((*filename == '/') && (filename < filename_end - 1))
1041 		filename ++;
1042 	/* Adjust filename_end so that filename + insert fits in 99 chars. */
1043 	suffix_length -= insert_length;
1044 	if (filename_end > filename + suffix_length)
1045 		filename_end = filename + suffix_length;
1046 	/* Calculate max size for "suffix" section (#3 above). */
1047 	suffix_length -= filename_end - filename;
1048 
1049 	/* Step 2: Locate the "prefix" section of the dirname, including
1050 	 * trailing '/'. */
1051 	prefix = src;
1052 	prefix_end = prefix + 155;
1053 	if (prefix_end > filename)
1054 		prefix_end = filename;
1055 	while (prefix_end > prefix && *prefix_end != '/')
1056 		prefix_end--;
1057 	if ((prefix_end < filename) && (*prefix_end == '/'))
1058 		prefix_end++;
1059 
1060 	/* Step 3: Locate the "suffix" section of the dirname,
1061 	 * including trailing '/'. */
1062 	suffix = prefix_end;
1063 	suffix_end = suffix + suffix_length; /* Enforce limit. */
1064 	if (suffix_end > filename)
1065 		suffix_end = filename;
1066 	if (suffix_end < suffix)
1067 		suffix_end = suffix;
1068 	while (suffix_end > suffix && *suffix_end != '/')
1069 		suffix_end--;
1070 	if ((suffix_end < filename) && (*suffix_end == '/'))
1071 		suffix_end++;
1072 
1073 	/* Step 4: Build the new name. */
1074 	/* The OpenBSD strlcpy function is safer, but less portable. */
1075 	/* Rather than maintain two versions, just use the strncpy version. */
1076 	p = dest;
1077 	if (prefix_end > prefix) {
1078 		strncpy(p, prefix, prefix_end - prefix);
1079 		p += prefix_end - prefix;
1080 	}
1081 	if (suffix_end > suffix) {
1082 		strncpy(p, suffix, suffix_end - suffix);
1083 		p += suffix_end - suffix;
1084 	}
1085 	if (insert != NULL) {
1086 		/* Note: assume insert does not have leading or trailing '/' */
1087 		strcpy(p, insert);
1088 		p += strlen(insert);
1089 		*p++ = '/';
1090 	}
1091 	strncpy(p, filename, filename_end - filename);
1092 	p += filename_end - filename;
1093 	if (need_slash)
1094 		*p++ = '/';
1095 	*p++ = '\0';
1096 
1097 	return (dest);
1098 }
1099 
1100 /*
1101  * The ustar header for the pax extended attributes must have a
1102  * reasonable name:  SUSv3 requires 'dirname'/PaxHeader.'pid'/'filename'
1103  * where 'pid' is the PID of the archiving process.  Unfortunately,
1104  * that makes testing a pain since the output varies for each run,
1105  * so I'm sticking with the simpler 'dirname'/PaxHeader/'filename'
1106  * for now.  (Someday, I'll make this settable.  Then I can use the
1107  * SUS recommendation as default and test harnesses can override it
1108  * to get predictable results.)
1109  *
1110  * Joerg Schilling has argued that this is unnecessary because, in
1111  * practice, if the pax extended attributes get extracted as regular
1112  * files, noone is going to bother reading those attributes to
1113  * manually restore them.  Based on this, 'star' uses
1114  * /tmp/PaxHeader/'basename' as the ustar header name.  This is a
1115  * tempting argument, in part because it's simpler than the SUSv3
1116  * recommendation, but I'm not entirely convinced.  I'm also
1117  * uncomfortable with the fact that "/tmp" is a Unix-ism.
1118  *
1119  * The following routine leverages build_ustar_entry_name() above and
1120  * so is simpler than you might think.  It just needs to provide the
1121  * additional path element and handle a few pathological cases).
1122  */
1123 static char *
1124 build_pax_attribute_name(char *dest, const char *src)
1125 {
1126 	char buff[64];
1127 	const char *p;
1128 
1129 	/* Handle the null filename case. */
1130 	if (src == NULL || *src == '\0') {
1131 		strcpy(dest, "PaxHeader/blank");
1132 		return (dest);
1133 	}
1134 
1135 	/* Prune final '/' and other unwanted final elements. */
1136 	p = src + strlen(src);
1137 	for (;;) {
1138 		/* Ends in "/", remove the '/' */
1139 		if (p > src && p[-1] == '/') {
1140 			--p;
1141 			continue;
1142 		}
1143 		/* Ends in "/.", remove the '.' */
1144 		if (p > src + 1 && p[-1] == '.'
1145 		    && p[-2] == '/') {
1146 			--p;
1147 			continue;
1148 		}
1149 		break;
1150 	}
1151 
1152 	/* Pathological case: After above, there was nothing left.
1153 	 * This includes "/." "/./." "/.//./." etc. */
1154 	if (p == src) {
1155 		strcpy(dest, "/PaxHeader/rootdir");
1156 		return (dest);
1157 	}
1158 
1159 	/* Convert unadorned "." into a suitable filename. */
1160 	if (*src == '.' && p == src + 1) {
1161 		strcpy(dest, "PaxHeader/currentdir");
1162 		return (dest);
1163 	}
1164 
1165 	/*
1166 	 * TODO: Push this string into the 'pax' structure to avoid
1167 	 * recomputing it every time.  That will also open the door
1168 	 * to having clients override it.
1169 	 */
1170 #if HAVE_GETPID && 0  /* Disable this for now; see above comment. */
1171 	sprintf(buff, "PaxHeader.%d", getpid());
1172 #else
1173 	/* If the platform can't fetch the pid, don't include it. */
1174 	strcpy(buff, "PaxHeader");
1175 #endif
1176 	/* General case: build a ustar-compatible name adding "/PaxHeader/". */
1177 	build_ustar_entry_name(dest, src, p - src, buff);
1178 
1179 	return (dest);
1180 }
1181 
1182 /* Write two null blocks for the end of archive */
1183 static int
1184 archive_write_pax_finish(struct archive_write *a)
1185 {
1186 	struct pax *pax;
1187 	int r;
1188 
1189 	if (a->compressor.write == NULL)
1190 		return (ARCHIVE_OK);
1191 
1192 	pax = (struct pax *)a->format_data;
1193 	r = write_nulls(a, 512 * 2);
1194 	return (r);
1195 }
1196 
1197 static int
1198 archive_write_pax_destroy(struct archive_write *a)
1199 {
1200 	struct pax *pax;
1201 
1202 	pax = (struct pax *)a->format_data;
1203 	archive_string_free(&pax->pax_header);
1204 	free(pax);
1205 	a->format_data = NULL;
1206 	return (ARCHIVE_OK);
1207 }
1208 
1209 static int
1210 archive_write_pax_finish_entry(struct archive_write *a)
1211 {
1212 	struct pax *pax;
1213 	int ret;
1214 
1215 	pax = (struct pax *)a->format_data;
1216 	ret = write_nulls(a, pax->entry_bytes_remaining + pax->entry_padding);
1217 	pax->entry_bytes_remaining = pax->entry_padding = 0;
1218 	return (ret);
1219 }
1220 
1221 static int
1222 write_nulls(struct archive_write *a, size_t padding)
1223 {
1224 	int ret, to_write;
1225 
1226 	while (padding > 0) {
1227 		to_write = padding < a->null_length ? padding : a->null_length;
1228 		ret = (a->compressor.write)(a, a->nulls, to_write);
1229 		if (ret != ARCHIVE_OK)
1230 			return (ret);
1231 		padding -= to_write;
1232 	}
1233 	return (ARCHIVE_OK);
1234 }
1235 
1236 static ssize_t
1237 archive_write_pax_data(struct archive_write *a, const void *buff, size_t s)
1238 {
1239 	struct pax *pax;
1240 	int ret;
1241 
1242 	pax = (struct pax *)a->format_data;
1243 	if (s > pax->entry_bytes_remaining)
1244 		s = pax->entry_bytes_remaining;
1245 
1246 	ret = (a->compressor.write)(a, buff, s);
1247 	pax->entry_bytes_remaining -= s;
1248 	if (ret == ARCHIVE_OK)
1249 		return (s);
1250 	else
1251 		return (ret);
1252 }
1253 
1254 static int
1255 has_non_ASCII(const wchar_t *wp)
1256 {
1257 	if (wp == NULL)
1258 		return (1);
1259 	while (*wp != L'\0' && *wp < 128)
1260 		wp++;
1261 	return (*wp != L'\0');
1262 }
1263 
1264 /*
1265  * Used by extended attribute support; encodes the name
1266  * so that there will be no '=' characters in the result.
1267  */
1268 static char *
1269 url_encode(const char *in)
1270 {
1271 	const char *s;
1272 	char *d;
1273 	int out_len = 0;
1274 	char *out;
1275 
1276 	for (s = in; *s != '\0'; s++) {
1277 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=')
1278 			out_len += 3;
1279 		else
1280 			out_len++;
1281 	}
1282 
1283 	out = (char *)malloc(out_len + 1);
1284 	if (out == NULL)
1285 		return (NULL);
1286 
1287 	for (s = in, d = out; *s != '\0'; s++) {
1288 		/* encode any non-printable ASCII character or '%' or '=' */
1289 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=') {
1290 			/* URL encoding is '%' followed by two hex digits */
1291 			*d++ = '%';
1292 			*d++ = "0123456789ABCDEF"[0x0f & (*s >> 4)];
1293 			*d++ = "0123456789ABCDEF"[0x0f & *s];
1294 		} else {
1295 			*d++ = *s;
1296 		}
1297 	}
1298 	*d = '\0';
1299 	return (out);
1300 }
1301 
1302 /*
1303  * Encode a sequence of bytes into a C string using base-64 encoding.
1304  *
1305  * Returns a null-terminated C string allocated with malloc(); caller
1306  * is responsible for freeing the result.
1307  */
1308 static char *
1309 base64_encode(const char *s, size_t len)
1310 {
1311 	static const char digits[64] =
1312 	    { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O',
1313 	      'P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d',
1314 	      'e','f','g','h','i','j','k','l','m','n','o','p','q','r','s',
1315 	      't','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
1316 	      '8','9','+','/' };
1317 	int v;
1318 	char *d, *out;
1319 
1320 	/* 3 bytes becomes 4 chars, but round up and allow for trailing NUL */
1321 	out = (char *)malloc((len * 4 + 2) / 3 + 1);
1322 	if (out == NULL)
1323 		return (NULL);
1324 	d = out;
1325 
1326 	/* Convert each group of 3 bytes into 4 characters. */
1327 	while (len >= 3) {
1328 		v = (((int)s[0] << 16) & 0xff0000)
1329 		    | (((int)s[1] << 8) & 0xff00)
1330 		    | (((int)s[2]) & 0x00ff);
1331 		s += 3;
1332 		len -= 3;
1333 		*d++ = digits[(v >> 18) & 0x3f];
1334 		*d++ = digits[(v >> 12) & 0x3f];
1335 		*d++ = digits[(v >> 6) & 0x3f];
1336 		*d++ = digits[(v) & 0x3f];
1337 	}
1338 	/* Handle final group of 1 byte (2 chars) or 2 bytes (3 chars). */
1339 	switch (len) {
1340 	case 0: break;
1341 	case 1:
1342 		v = (((int)s[0] << 16) & 0xff0000);
1343 		*d++ = digits[(v >> 18) & 0x3f];
1344 		*d++ = digits[(v >> 12) & 0x3f];
1345 		break;
1346 	case 2:
1347 		v = (((int)s[0] << 16) & 0xff0000)
1348 		    | (((int)s[1] << 8) & 0xff00);
1349 		*d++ = digits[(v >> 18) & 0x3f];
1350 		*d++ = digits[(v >> 12) & 0x3f];
1351 		*d++ = digits[(v >> 6) & 0x3f];
1352 		break;
1353 	}
1354 	/* Add trailing NUL character so output is a valid C string. */
1355 	*d++ = '\0';
1356 	return (out);
1357 }
1358