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 1.49 2008/09/30 03:57:07 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_name = "pax";
115 	a->format_write_header = archive_write_pax_header;
116 	a->format_write_data = archive_write_pax_data;
117 	a->format_finish = archive_write_pax_finish;
118 	a->format_destroy = archive_write_pax_destroy;
119 	a->format_finish_entry = archive_write_pax_finish_entry;
120 	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
121 	a->archive.archive_format_name = "POSIX pax interchange";
122 	return (ARCHIVE_OK);
123 }
124 
125 /*
126  * Note: This code assumes that 'nanos' has the same sign as 'sec',
127  * which implies that sec=-1, nanos=200000000 represents -1.2 seconds
128  * and not -0.8 seconds.  This is a pretty pedantic point, as we're
129  * unlikely to encounter many real files created before Jan 1, 1970,
130  * much less ones with timestamps recorded to sub-second resolution.
131  */
132 static void
133 add_pax_attr_time(struct archive_string *as, const char *key,
134     int64_t sec, unsigned long nanos)
135 {
136 	int digit, i;
137 	char *t;
138 	/*
139 	 * Note that each byte contributes fewer than 3 base-10
140 	 * digits, so this will always be big enough.
141 	 */
142 	char tmp[1 + 3*sizeof(sec) + 1 + 3*sizeof(nanos)];
143 
144 	tmp[sizeof(tmp) - 1] = 0;
145 	t = tmp + sizeof(tmp) - 1;
146 
147 	/* Skip trailing zeros in the fractional part. */
148 	for (digit = 0, i = 10; i > 0 && digit == 0; i--) {
149 		digit = nanos % 10;
150 		nanos /= 10;
151 	}
152 
153 	/* Only format the fraction if it's non-zero. */
154 	if (i > 0) {
155 		while (i > 0) {
156 			*--t = "0123456789"[digit];
157 			digit = nanos % 10;
158 			nanos /= 10;
159 			i--;
160 		}
161 		*--t = '.';
162 	}
163 	t = format_int(t, sec);
164 
165 	add_pax_attr(as, key, t);
166 }
167 
168 static char *
169 format_int(char *t, int64_t i)
170 {
171 	int sign;
172 
173 	if (i < 0) {
174 		sign = -1;
175 		i = -i;
176 	} else
177 		sign = 1;
178 
179 	do {
180 		*--t = "0123456789"[i % 10];
181 	} while (i /= 10);
182 	if (sign < 0)
183 		*--t = '-';
184 	return (t);
185 }
186 
187 static void
188 add_pax_attr_int(struct archive_string *as, const char *key, int64_t value)
189 {
190 	char tmp[1 + 3 * sizeof(value)];
191 
192 	tmp[sizeof(tmp) - 1] = 0;
193 	add_pax_attr(as, key, format_int(tmp + sizeof(tmp) - 1, value));
194 }
195 
196 static char *
197 utf8_encode(const wchar_t *wval)
198 {
199 	int utf8len;
200 	const wchar_t *wp;
201 	unsigned long wc;
202 	char *utf8_value, *p;
203 
204 	utf8len = 0;
205 	for (wp = wval; *wp != L'\0'; ) {
206 		wc = *wp++;
207 
208 		if (wc >= 0xd800 && wc <= 0xdbff
209 		    && *wp >= 0xdc00 && *wp <= 0xdfff) {
210 			/* This is a surrogate pair.  Combine into a
211 			 * full Unicode value before encoding into
212 			 * UTF-8. */
213 			wc = (wc - 0xd800) << 10; /* High 10 bits */
214 			wc += (*wp++ - 0xdc00); /* Low 10 bits */
215 			wc += 0x10000; /* Skip BMP */
216 		}
217 		if (wc <= 0x7f)
218 			utf8len++;
219 		else if (wc <= 0x7ff)
220 			utf8len += 2;
221 		else if (wc <= 0xffff)
222 			utf8len += 3;
223 		else if (wc <= 0x1fffff)
224 			utf8len += 4;
225 		else if (wc <= 0x3ffffff)
226 			utf8len += 5;
227 		else if (wc <= 0x7fffffff)
228 			utf8len += 6;
229 		/* Ignore larger values; UTF-8 can't encode them. */
230 	}
231 
232 	utf8_value = (char *)malloc(utf8len + 1);
233 	if (utf8_value == NULL) {
234 		__archive_errx(1, "Not enough memory for attributes");
235 		return (NULL);
236 	}
237 
238 	for (wp = wval, p = utf8_value; *wp != L'\0'; ) {
239 		wc = *wp++;
240 		if (wc >= 0xd800 && wc <= 0xdbff
241 		    && *wp >= 0xdc00 && *wp <= 0xdfff) {
242 			/* Combine surrogate pair. */
243 			wc = (wc - 0xd800) << 10;
244 			wc += *wp++ - 0xdc00 + 0x10000;
245 		}
246 		if (wc <= 0x7f) {
247 			*p++ = (char)wc;
248 		} else if (wc <= 0x7ff) {
249 			p[0] = 0xc0 | ((wc >> 6) & 0x1f);
250 			p[1] = 0x80 | (wc & 0x3f);
251 			p += 2;
252 		} else if (wc <= 0xffff) {
253 			p[0] = 0xe0 | ((wc >> 12) & 0x0f);
254 			p[1] = 0x80 | ((wc >> 6) & 0x3f);
255 			p[2] = 0x80 | (wc & 0x3f);
256 			p += 3;
257 		} else if (wc <= 0x1fffff) {
258 			p[0] = 0xf0 | ((wc >> 18) & 0x07);
259 			p[1] = 0x80 | ((wc >> 12) & 0x3f);
260 			p[2] = 0x80 | ((wc >> 6) & 0x3f);
261 			p[3] = 0x80 | (wc & 0x3f);
262 			p += 4;
263 		} else if (wc <= 0x3ffffff) {
264 			p[0] = 0xf8 | ((wc >> 24) & 0x03);
265 			p[1] = 0x80 | ((wc >> 18) & 0x3f);
266 			p[2] = 0x80 | ((wc >> 12) & 0x3f);
267 			p[3] = 0x80 | ((wc >> 6) & 0x3f);
268 			p[4] = 0x80 | (wc & 0x3f);
269 			p += 5;
270 		} else if (wc <= 0x7fffffff) {
271 			p[0] = 0xfc | ((wc >> 30) & 0x01);
272 			p[1] = 0x80 | ((wc >> 24) & 0x3f);
273 			p[1] = 0x80 | ((wc >> 18) & 0x3f);
274 			p[2] = 0x80 | ((wc >> 12) & 0x3f);
275 			p[3] = 0x80 | ((wc >> 6) & 0x3f);
276 			p[4] = 0x80 | (wc & 0x3f);
277 			p += 6;
278 		}
279 		/* Ignore larger values; UTF-8 can't encode them. */
280 	}
281 	*p = '\0';
282 
283 	return (utf8_value);
284 }
285 
286 static void
287 add_pax_attr_w(struct archive_string *as, const char *key, const wchar_t *wval)
288 {
289 	char *utf8_value = utf8_encode(wval);
290 	if (utf8_value == NULL)
291 		return;
292 	add_pax_attr(as, key, utf8_value);
293 	free(utf8_value);
294 }
295 
296 /*
297  * Add a key/value attribute to the pax header.  This function handles
298  * the length field and various other syntactic requirements.
299  */
300 static void
301 add_pax_attr(struct archive_string *as, const char *key, const char *value)
302 {
303 	int digits, i, len, next_ten;
304 	char tmp[1 + 3 * sizeof(int)];	/* < 3 base-10 digits per byte */
305 
306 	/*-
307 	 * PAX attributes have the following layout:
308 	 *     <len> <space> <key> <=> <value> <nl>
309 	 */
310 	len = 1 + strlen(key) + 1 + strlen(value) + 1;
311 
312 	/*
313 	 * The <len> field includes the length of the <len> field, so
314 	 * computing the correct length is tricky.  I start by
315 	 * counting the number of base-10 digits in 'len' and
316 	 * computing the next higher power of 10.
317 	 */
318 	next_ten = 1;
319 	digits = 0;
320 	i = len;
321 	while (i > 0) {
322 		i = i / 10;
323 		digits++;
324 		next_ten = next_ten * 10;
325 	}
326 	/*
327 	 * For example, if string without the length field is 99
328 	 * chars, then adding the 2 digit length "99" will force the
329 	 * total length past 100, requiring an extra digit.  The next
330 	 * statement adjusts for this effect.
331 	 */
332 	if (len + digits >= next_ten)
333 		digits++;
334 
335 	/* Now, we have the right length so we can build the line. */
336 	tmp[sizeof(tmp) - 1] = 0;	/* Null-terminate the work area. */
337 	archive_strcat(as, format_int(tmp + sizeof(tmp) - 1, len + digits));
338 	archive_strappend_char(as, ' ');
339 	archive_strcat(as, key);
340 	archive_strappend_char(as, '=');
341 	archive_strcat(as, value);
342 	archive_strappend_char(as, '\n');
343 }
344 
345 static void
346 archive_write_pax_header_xattrs(struct pax *pax, struct archive_entry *entry)
347 {
348 	struct archive_string s;
349 	int i = archive_entry_xattr_reset(entry);
350 
351 	while (i--) {
352 		const char *name;
353 		const void *value;
354 		char *encoded_value;
355 		char *url_encoded_name = NULL, *encoded_name = NULL;
356 		wchar_t *wcs_name = NULL;
357 		size_t size;
358 
359 		archive_entry_xattr_next(entry, &name, &value, &size);
360 		/* Name is URL-encoded, then converted to wchar_t,
361 		 * then UTF-8 encoded. */
362 		url_encoded_name = url_encode(name);
363 		if (url_encoded_name != NULL) {
364 			/* Convert narrow-character to wide-character. */
365 			int wcs_length = strlen(url_encoded_name);
366 			wcs_name = (wchar_t *)malloc((wcs_length + 1) * sizeof(wchar_t));
367 			if (wcs_name == NULL)
368 				__archive_errx(1, "No memory for xattr conversion");
369 			mbstowcs(wcs_name, url_encoded_name, wcs_length);
370 			wcs_name[wcs_length] = 0;
371 			free(url_encoded_name); /* Done with this. */
372 		}
373 		if (wcs_name != NULL) {
374 			encoded_name = utf8_encode(wcs_name);
375 			free(wcs_name); /* Done with wchar_t name. */
376 		}
377 
378 		encoded_value = base64_encode((const char *)value, size);
379 
380 		if (encoded_name != NULL && encoded_value != NULL) {
381 			archive_string_init(&s);
382 			archive_strcpy(&s, "LIBARCHIVE.xattr.");
383 			archive_strcat(&s, encoded_name);
384 			add_pax_attr(&(pax->pax_header), s.s, encoded_value);
385 			archive_string_free(&s);
386 		}
387 		free(encoded_name);
388 		free(encoded_value);
389 	}
390 }
391 
392 /*
393  * TODO: Consider adding 'comment' and 'charset' fields to
394  * archive_entry so that clients can specify them.  Also, consider
395  * adding generic key/value tags so clients can add arbitrary
396  * key/value data.
397  */
398 static int
399 archive_write_pax_header(struct archive_write *a,
400     struct archive_entry *entry_original)
401 {
402 	struct archive_entry *entry_main;
403 	const char *p;
404 	char *t;
405 	const wchar_t *wp;
406 	const char *suffix;
407 	int need_extension, r, ret;
408 	struct pax *pax;
409 	const char *hdrcharset = NULL;
410 	const char *hardlink;
411 	const char *path = NULL, *linkpath = NULL;
412 	const char *uname = NULL, *gname = NULL;
413 	const wchar_t *path_w = NULL, *linkpath_w = NULL;
414 	const wchar_t *uname_w = NULL, *gname_w = NULL;
415 
416 	char paxbuff[512];
417 	char ustarbuff[512];
418 	char ustar_entry_name[256];
419 	char pax_entry_name[256];
420 
421 	ret = ARCHIVE_OK;
422 	need_extension = 0;
423 	pax = (struct pax *)a->format_data;
424 
425 	hardlink = archive_entry_hardlink(entry_original);
426 
427 	/* Make sure this is a type of entry that we can handle here */
428 	if (hardlink == NULL) {
429 		switch (archive_entry_filetype(entry_original)) {
430 		case AE_IFBLK:
431 		case AE_IFCHR:
432 		case AE_IFIFO:
433 		case AE_IFLNK:
434 		case AE_IFREG:
435 			break;
436 		case AE_IFDIR:
437 			/*
438 			 * Ensure a trailing '/'.  Modify the original
439 			 * entry so the client sees the change.
440 			 */
441 			p = archive_entry_pathname(entry_original);
442 			if (p[strlen(p) - 1] != '/') {
443 				t = (char *)malloc(strlen(p) + 2);
444 				if (t == NULL) {
445 					archive_set_error(&a->archive, ENOMEM,
446 					"Can't allocate pax data");
447 					return(ARCHIVE_FATAL);
448 				}
449 				strcpy(t, p);
450 				strcat(t, "/");
451 				archive_entry_copy_pathname(entry_original, t);
452 				free(t);
453 			}
454 			break;
455 		default:
456 			archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
457 			    "tar format cannot archive this (type=0%lo)",
458 			    (unsigned long)archive_entry_filetype(entry_original));
459 			return (ARCHIVE_WARN);
460 		}
461 	}
462 
463 	/* Copy entry so we can modify it as needed. */
464 	entry_main = archive_entry_clone(entry_original);
465 	archive_string_empty(&(pax->pax_header)); /* Blank our work area. */
466 
467 	/*
468 	 * First, check the name fields and see if any of them
469 	 * require binary coding.  If any of them does, then all of
470 	 * them do.
471 	 */
472 	hdrcharset = NULL;
473 	path = archive_entry_pathname(entry_main);
474 	path_w = archive_entry_pathname_w(entry_main);
475 	if (path != NULL && path_w == NULL) {
476 		archive_set_error(&a->archive, EILSEQ,
477 		    "Can't translate pathname '%s' to UTF-8", path);
478 		ret = ARCHIVE_WARN;
479 		hdrcharset = "BINARY";
480 	}
481 	uname = archive_entry_uname(entry_main);
482 	uname_w = archive_entry_uname_w(entry_main);
483 	if (uname != NULL && uname_w == NULL) {
484 		archive_set_error(&a->archive, EILSEQ,
485 		    "Can't translate uname '%s' to UTF-8", uname);
486 		ret = ARCHIVE_WARN;
487 		hdrcharset = "BINARY";
488 	}
489 	gname = archive_entry_gname(entry_main);
490 	gname_w = archive_entry_gname_w(entry_main);
491 	if (gname != NULL && gname_w == NULL) {
492 		archive_set_error(&a->archive, EILSEQ,
493 		    "Can't translate gname '%s' to UTF-8", gname);
494 		ret = ARCHIVE_WARN;
495 		hdrcharset = "BINARY";
496 	}
497 	linkpath = hardlink;
498 	if (linkpath != NULL) {
499 		linkpath_w = archive_entry_hardlink_w(entry_main);
500 	} else {
501 		linkpath = archive_entry_symlink(entry_main);
502 		if (linkpath != NULL)
503 			linkpath_w = archive_entry_symlink_w(entry_main);
504 	}
505 	if (linkpath != NULL && linkpath_w == NULL) {
506 		archive_set_error(&a->archive, EILSEQ,
507 		    "Can't translate linkpath '%s' to UTF-8", linkpath);
508 		ret = ARCHIVE_WARN;
509 		hdrcharset = "BINARY";
510 	}
511 
512 	/* Store the header encoding first, to be nice to readers. */
513 	if (hdrcharset != NULL)
514 		add_pax_attr(&(pax->pax_header), "hdrcharset", hdrcharset);
515 
516 
517 	/*
518 	 * If name is too long, or has non-ASCII characters, add
519 	 * 'path' to pax extended attrs.  (Note that an unconvertible
520 	 * name must have non-ASCII characters.)
521 	 */
522 	if (path == NULL) {
523 		/* We don't have a narrow version, so we have to store
524 		 * the wide version. */
525 		add_pax_attr_w(&(pax->pax_header), "path", path_w);
526 		archive_entry_set_pathname(entry_main, "@WidePath");
527 		need_extension = 1;
528 	} else if (has_non_ASCII(path_w)) {
529 		/* We have non-ASCII characters. */
530 		if (path_w == NULL || hdrcharset != NULL) {
531 			/* Can't do UTF-8, so store it raw. */
532 			add_pax_attr(&(pax->pax_header), "path", path);
533 		} else {
534 			/* Store UTF-8 */
535 			add_pax_attr_w(&(pax->pax_header),
536 			    "path", path_w);
537 		}
538 		archive_entry_set_pathname(entry_main,
539 		    build_ustar_entry_name(ustar_entry_name,
540 			path, strlen(path), NULL));
541 		need_extension = 1;
542 	} else {
543 		/* We have an all-ASCII path; we'd like to just store
544 		 * it in the ustar header if it will fit.  Yes, this
545 		 * duplicates some of the logic in
546 		 * write_set_format_ustar.c
547 		 */
548 		if (strlen(path) <= 100) {
549 			/* Fits in the old 100-char tar name field. */
550 		} else {
551 			/* Find largest suffix that will fit. */
552 			/* Note: strlen() > 100, so strlen() - 100 - 1 >= 0 */
553 			suffix = strchr(path + strlen(path) - 100 - 1, '/');
554 			/* Don't attempt an empty prefix. */
555 			if (suffix == path)
556 				suffix = strchr(suffix + 1, '/');
557 			/* We can put it in the ustar header if it's
558 			 * all ASCII and it's either <= 100 characters
559 			 * or can be split at a '/' into a prefix <=
560 			 * 155 chars and a suffix <= 100 chars.  (Note
561 			 * the strchr() above will return NULL exactly
562 			 * when the path can't be split.)
563 			 */
564 			if (suffix == NULL       /* Suffix > 100 chars. */
565 			    || suffix[1] == '\0'    /* empty suffix */
566 			    || suffix - path > 155)  /* Prefix > 155 chars */
567 			{
568 				if (path_w == NULL || hdrcharset != NULL) {
569 					/* Can't do UTF-8, so store it raw. */
570 					add_pax_attr(&(pax->pax_header),
571 					    "path", path);
572 				} else {
573 					/* Store UTF-8 */
574 					add_pax_attr_w(&(pax->pax_header),
575 					    "path", path_w);
576 				}
577 				archive_entry_set_pathname(entry_main,
578 				    build_ustar_entry_name(ustar_entry_name,
579 					path, strlen(path), NULL));
580 				need_extension = 1;
581 			}
582 		}
583 	}
584 
585 	if (linkpath != NULL) {
586 		/* If link name is too long or has non-ASCII characters, add
587 		 * 'linkpath' to pax extended attrs. */
588 		if (strlen(linkpath) > 100 || linkpath_w == NULL
589 		    || linkpath_w == NULL || has_non_ASCII(linkpath_w)) {
590 			if (linkpath_w == NULL || hdrcharset != NULL)
591 				/* If the linkpath is not convertible
592 				 * to wide, or we're encoding in
593 				 * binary anyway, store it raw. */
594 				add_pax_attr(&(pax->pax_header),
595 				    "linkpath", linkpath);
596 			else
597 				/* If the link is long or has a
598 				 * non-ASCII character, store it as a
599 				 * pax extended attribute. */
600 				add_pax_attr_w(&(pax->pax_header),
601 				    "linkpath", linkpath_w);
602 			if (strlen(linkpath) > 100) {
603 				if (hardlink != NULL)
604 					archive_entry_set_hardlink(entry_main,
605 					    "././@LongHardLink");
606 				else
607 					archive_entry_set_symlink(entry_main,
608 					    "././@LongSymLink");
609 			}
610 			need_extension = 1;
611 		}
612 	}
613 
614 	/* If file size is too large, add 'size' to pax extended attrs. */
615 	if (archive_entry_size(entry_main) >= (((int64_t)1) << 33)) {
616 		add_pax_attr_int(&(pax->pax_header), "size",
617 		    archive_entry_size(entry_main));
618 		need_extension = 1;
619 	}
620 
621 	/* If numeric GID is too large, add 'gid' to pax extended attrs. */
622 	if (archive_entry_gid(entry_main) >= (1 << 18)) {
623 		add_pax_attr_int(&(pax->pax_header), "gid",
624 		    archive_entry_gid(entry_main));
625 		need_extension = 1;
626 	}
627 
628 	/* If group name is too large or has non-ASCII characters, add
629 	 * 'gname' to pax extended attrs. */
630 	if (gname != NULL) {
631 		if (strlen(gname) > 31
632 		    || gname_w == NULL
633 		    || has_non_ASCII(gname_w))
634 		{
635 			if (gname_w == NULL || hdrcharset != NULL) {
636 				add_pax_attr(&(pax->pax_header),
637 				    "gname", gname);
638 			} else  {
639 				add_pax_attr_w(&(pax->pax_header),
640 				    "gname", gname_w);
641 			}
642 			need_extension = 1;
643 		}
644 	}
645 
646 	/* If numeric UID is too large, add 'uid' to pax extended attrs. */
647 	if (archive_entry_uid(entry_main) >= (1 << 18)) {
648 		add_pax_attr_int(&(pax->pax_header), "uid",
649 		    archive_entry_uid(entry_main));
650 		need_extension = 1;
651 	}
652 
653 	/* Add 'uname' to pax extended attrs if necessary. */
654 	if (uname != NULL) {
655 		if (strlen(uname) > 31
656 		    || uname_w == NULL
657 		    || has_non_ASCII(uname_w))
658 		{
659 			if (uname_w == NULL || hdrcharset != NULL) {
660 				add_pax_attr(&(pax->pax_header),
661 				    "uname", uname);
662 			} else {
663 				add_pax_attr_w(&(pax->pax_header),
664 				    "uname", uname_w);
665 			}
666 			need_extension = 1;
667 		}
668 	}
669 
670 	/*
671 	 * POSIX/SUSv3 doesn't provide a standard key for large device
672 	 * numbers.  I use the same keys here that Joerg Schilling
673 	 * used for 'star.'  (Which, somewhat confusingly, are called
674 	 * "devXXX" even though they code "rdev" values.)  No doubt,
675 	 * other implementations use other keys.  Note that there's no
676 	 * reason we can't write the same information into a number of
677 	 * different keys.
678 	 *
679 	 * Of course, this is only needed for block or char device entries.
680 	 */
681 	if (archive_entry_filetype(entry_main) == AE_IFBLK
682 	    || archive_entry_filetype(entry_main) == AE_IFCHR) {
683 		/*
684 		 * If rdevmajor is too large, add 'SCHILY.devmajor' to
685 		 * extended attributes.
686 		 */
687 		dev_t rdevmajor, rdevminor;
688 		rdevmajor = archive_entry_rdevmajor(entry_main);
689 		rdevminor = archive_entry_rdevminor(entry_main);
690 		if (rdevmajor >= (1 << 18)) {
691 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devmajor",
692 			    rdevmajor);
693 			/*
694 			 * Non-strict formatting below means we don't
695 			 * have to truncate here.  Not truncating improves
696 			 * the chance that some more modern tar archivers
697 			 * (such as GNU tar 1.13) can restore the full
698 			 * value even if they don't understand the pax
699 			 * extended attributes.  See my rant below about
700 			 * file size fields for additional details.
701 			 */
702 			/* archive_entry_set_rdevmajor(entry_main,
703 			   rdevmajor & ((1 << 18) - 1)); */
704 			need_extension = 1;
705 		}
706 
707 		/*
708 		 * If devminor is too large, add 'SCHILY.devminor' to
709 		 * extended attributes.
710 		 */
711 		if (rdevminor >= (1 << 18)) {
712 			add_pax_attr_int(&(pax->pax_header), "SCHILY.devminor",
713 			    rdevminor);
714 			/* Truncation is not necessary here, either. */
715 			/* archive_entry_set_rdevminor(entry_main,
716 			   rdevminor & ((1 << 18) - 1)); */
717 			need_extension = 1;
718 		}
719 	}
720 
721 	/*
722 	 * Technically, the mtime field in the ustar header can
723 	 * support 33 bits, but many platforms use signed 32-bit time
724 	 * values.  The cutoff of 0x7fffffff here is a compromise.
725 	 * Yes, this check is duplicated just below; this helps to
726 	 * avoid writing an mtime attribute just to handle a
727 	 * high-resolution timestamp in "restricted pax" mode.
728 	 */
729 	if (!need_extension &&
730 	    ((archive_entry_mtime(entry_main) < 0)
731 		|| (archive_entry_mtime(entry_main) >= 0x7fffffff)))
732 		need_extension = 1;
733 
734 	/* I use a star-compatible file flag attribute. */
735 	p = archive_entry_fflags_text(entry_main);
736 	if (!need_extension && p != NULL  &&  *p != '\0')
737 		need_extension = 1;
738 
739 	/* If there are non-trivial ACL entries, we need an extension. */
740 	if (!need_extension && archive_entry_acl_count(entry_original,
741 		ARCHIVE_ENTRY_ACL_TYPE_ACCESS) > 0)
742 		need_extension = 1;
743 
744 	/* If there are non-trivial ACL entries, we need an extension. */
745 	if (!need_extension && archive_entry_acl_count(entry_original,
746 		ARCHIVE_ENTRY_ACL_TYPE_DEFAULT) > 0)
747 		need_extension = 1;
748 
749 	/* If there are extended attributes, we need an extension */
750 	if (!need_extension && archive_entry_xattr_count(entry_original) > 0)
751 		need_extension = 1;
752 
753 	/*
754 	 * The following items are handled differently in "pax
755 	 * restricted" format.  In particular, in "pax restricted"
756 	 * format they won't be added unless need_extension is
757 	 * already set (we're already generating an extended header, so
758 	 * may as well include these).
759 	 */
760 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED ||
761 	    need_extension) {
762 
763 		if (archive_entry_mtime(entry_main) < 0  ||
764 		    archive_entry_mtime(entry_main) >= 0x7fffffff  ||
765 		    archive_entry_mtime_nsec(entry_main) != 0)
766 			add_pax_attr_time(&(pax->pax_header), "mtime",
767 			    archive_entry_mtime(entry_main),
768 			    archive_entry_mtime_nsec(entry_main));
769 
770 		if (archive_entry_ctime(entry_main) != 0  ||
771 		    archive_entry_ctime_nsec(entry_main) != 0)
772 			add_pax_attr_time(&(pax->pax_header), "ctime",
773 			    archive_entry_ctime(entry_main),
774 			    archive_entry_ctime_nsec(entry_main));
775 
776 		if (archive_entry_atime(entry_main) != 0 ||
777 		    archive_entry_atime_nsec(entry_main) != 0)
778 			add_pax_attr_time(&(pax->pax_header), "atime",
779 			    archive_entry_atime(entry_main),
780 			    archive_entry_atime_nsec(entry_main));
781 
782 		/* Store birth/creationtime only if it's earlier than mtime */
783 		if (archive_entry_birthtime_is_set(entry_main) &&
784 		    archive_entry_birthtime(entry_main)
785 		    < archive_entry_mtime(entry_main))
786 			add_pax_attr_time(&(pax->pax_header),
787 			    "LIBARCHIVE.creationtime",
788 			    archive_entry_birthtime(entry_main),
789 			    archive_entry_birthtime_nsec(entry_main));
790 
791 		/* I use a star-compatible file flag attribute. */
792 		p = archive_entry_fflags_text(entry_main);
793 		if (p != NULL  &&  *p != '\0')
794 			add_pax_attr(&(pax->pax_header), "SCHILY.fflags", p);
795 
796 		/* I use star-compatible ACL attributes. */
797 		wp = archive_entry_acl_text_w(entry_original,
798 		    ARCHIVE_ENTRY_ACL_TYPE_ACCESS |
799 		    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID);
800 		if (wp != NULL && *wp != L'\0')
801 			add_pax_attr_w(&(pax->pax_header),
802 			    "SCHILY.acl.access", wp);
803 		wp = archive_entry_acl_text_w(entry_original,
804 		    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT |
805 		    ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID);
806 		if (wp != NULL && *wp != L'\0')
807 			add_pax_attr_w(&(pax->pax_header),
808 			    "SCHILY.acl.default", wp);
809 
810 		/* Include star-compatible metadata info. */
811 		/* Note: "SCHILY.dev{major,minor}" are NOT the
812 		 * major/minor portions of "SCHILY.dev". */
813 		add_pax_attr_int(&(pax->pax_header), "SCHILY.dev",
814 		    archive_entry_dev(entry_main));
815 		add_pax_attr_int(&(pax->pax_header), "SCHILY.ino",
816 		    archive_entry_ino(entry_main));
817 		add_pax_attr_int(&(pax->pax_header), "SCHILY.nlink",
818 		    archive_entry_nlink(entry_main));
819 
820 		/* Store extended attributes */
821 		archive_write_pax_header_xattrs(pax, entry_original);
822 	}
823 
824 	/* Only regular files have data. */
825 	if (archive_entry_filetype(entry_main) != AE_IFREG)
826 		archive_entry_set_size(entry_main, 0);
827 
828 	/*
829 	 * Pax-restricted does not store data for hardlinks, in order
830 	 * to improve compatibility with ustar.
831 	 */
832 	if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE &&
833 	    hardlink != NULL)
834 		archive_entry_set_size(entry_main, 0);
835 
836 	/*
837 	 * XXX Full pax interchange format does permit a hardlink
838 	 * entry to have data associated with it.  I'm not supporting
839 	 * that here because the client expects me to tell them whether
840 	 * or not this format expects data for hardlinks.  If I
841 	 * don't check here, then every pax archive will end up with
842 	 * duplicated data for hardlinks.  Someday, there may be
843 	 * need to select this behavior, in which case the following
844 	 * will need to be revisited. XXX
845 	 */
846 	if (hardlink != NULL)
847 		archive_entry_set_size(entry_main, 0);
848 
849 	/* Format 'ustar' header for main entry.
850 	 *
851 	 * The trouble with file size: If the reader can't understand
852 	 * the file size, they may not be able to locate the next
853 	 * entry and the rest of the archive is toast.  Pax-compliant
854 	 * readers are supposed to ignore the file size in the main
855 	 * header, so the question becomes how to maximize portability
856 	 * for readers that don't support pax attribute extensions.
857 	 * For maximum compatibility, I permit numeric extensions in
858 	 * the main header so that the file size stored will always be
859 	 * correct, even if it's in a format that only some
860 	 * implementations understand.  The technique used here is:
861 	 *
862 	 *  a) If possible, follow the standard exactly.  This handles
863 	 *  files up to 8 gigabytes minus 1.
864 	 *
865 	 *  b) If that fails, try octal but omit the field terminator.
866 	 *  That handles files up to 64 gigabytes minus 1.
867 	 *
868 	 *  c) Otherwise, use base-256 extensions.  That handles files
869 	 *  up to 2^63 in this implementation, with the potential to
870 	 *  go up to 2^94.  That should hold us for a while. ;-)
871 	 *
872 	 * The non-strict formatter uses similar logic for other
873 	 * numeric fields, though they're less critical.
874 	 */
875 	__archive_write_format_header_ustar(a, ustarbuff, entry_main, -1, 0);
876 
877 	/* If we built any extended attributes, write that entry first. */
878 	if (archive_strlen(&(pax->pax_header)) > 0) {
879 		struct archive_entry *pax_attr_entry;
880 		time_t s;
881 		uid_t uid;
882 		gid_t gid;
883 		mode_t mode;
884 		long ns;
885 
886 		pax_attr_entry = archive_entry_new();
887 		p = archive_entry_pathname(entry_main);
888 		archive_entry_set_pathname(pax_attr_entry,
889 		    build_pax_attribute_name(pax_entry_name, p));
890 		archive_entry_set_size(pax_attr_entry,
891 		    archive_strlen(&(pax->pax_header)));
892 		/* Copy uid/gid (but clip to ustar limits). */
893 		uid = archive_entry_uid(entry_main);
894 		if (uid >= 1 << 18)
895 			uid = (1 << 18) - 1;
896 		archive_entry_set_uid(pax_attr_entry, uid);
897 		gid = archive_entry_gid(entry_main);
898 		if (gid >= 1 << 18)
899 			gid = (1 << 18) - 1;
900 		archive_entry_set_gid(pax_attr_entry, gid);
901 		/* Copy mode over (but not setuid/setgid bits) */
902 		mode = archive_entry_mode(entry_main);
903 #ifdef S_ISUID
904 		mode &= ~S_ISUID;
905 #endif
906 #ifdef S_ISGID
907 		mode &= ~S_ISGID;
908 #endif
909 #ifdef S_ISVTX
910 		mode &= ~S_ISVTX;
911 #endif
912 		archive_entry_set_mode(pax_attr_entry, mode);
913 
914 		/* Copy uname/gname. */
915 		archive_entry_set_uname(pax_attr_entry,
916 		    archive_entry_uname(entry_main));
917 		archive_entry_set_gname(pax_attr_entry,
918 		    archive_entry_gname(entry_main));
919 
920 		/* Copy mtime, but clip to ustar limits. */
921 		s = archive_entry_mtime(entry_main);
922 		ns = archive_entry_mtime_nsec(entry_main);
923 		if (s < 0) { s = 0; ns = 0; }
924 		if (s > 0x7fffffff) { s = 0x7fffffff; ns = 0; }
925 		archive_entry_set_mtime(pax_attr_entry, s, ns);
926 
927 		/* Ditto for atime. */
928 		s = archive_entry_atime(entry_main);
929 		ns = archive_entry_atime_nsec(entry_main);
930 		if (s < 0) { s = 0; ns = 0; }
931 		if (s > 0x7fffffff) { s = 0x7fffffff; ns = 0; }
932 		archive_entry_set_atime(pax_attr_entry, s, ns);
933 
934 		/* Standard ustar doesn't support ctime. */
935 		archive_entry_set_ctime(pax_attr_entry, 0, 0);
936 
937 		r = __archive_write_format_header_ustar(a, paxbuff,
938 		    pax_attr_entry, 'x', 1);
939 
940 		archive_entry_free(pax_attr_entry);
941 
942 		/* Note that the 'x' header shouldn't ever fail to format */
943 		if (r != 0) {
944 			const char *msg = "archive_write_pax_header: "
945 			    "'x' header failed?!  This can't happen.\n";
946 			write(2, msg, strlen(msg));
947 			exit(1);
948 		}
949 		r = (a->compressor.write)(a, paxbuff, 512);
950 		if (r != ARCHIVE_OK) {
951 			pax->entry_bytes_remaining = 0;
952 			pax->entry_padding = 0;
953 			return (ARCHIVE_FATAL);
954 		}
955 
956 		pax->entry_bytes_remaining = archive_strlen(&(pax->pax_header));
957 		pax->entry_padding = 0x1ff & (-(int64_t)pax->entry_bytes_remaining);
958 
959 		r = (a->compressor.write)(a, pax->pax_header.s,
960 		    archive_strlen(&(pax->pax_header)));
961 		if (r != ARCHIVE_OK) {
962 			/* If a write fails, we're pretty much toast. */
963 			return (ARCHIVE_FATAL);
964 		}
965 		/* Pad out the end of the entry. */
966 		r = write_nulls(a, pax->entry_padding);
967 		if (r != ARCHIVE_OK) {
968 			/* If a write fails, we're pretty much toast. */
969 			return (ARCHIVE_FATAL);
970 		}
971 		pax->entry_bytes_remaining = pax->entry_padding = 0;
972 	}
973 
974 	/* Write the header for main entry. */
975 	r = (a->compressor.write)(a, ustarbuff, 512);
976 	if (r != ARCHIVE_OK)
977 		return (r);
978 
979 	/*
980 	 * Inform the client of the on-disk size we're using, so
981 	 * they can avoid unnecessarily writing a body for something
982 	 * that we're just going to ignore.
983 	 */
984 	archive_entry_set_size(entry_original, archive_entry_size(entry_main));
985 	pax->entry_bytes_remaining = archive_entry_size(entry_main);
986 	pax->entry_padding = 0x1ff & (-(int64_t)pax->entry_bytes_remaining);
987 	archive_entry_free(entry_main);
988 
989 	return (ret);
990 }
991 
992 /*
993  * We need a valid name for the regular 'ustar' entry.  This routine
994  * tries to hack something more-or-less reasonable.
995  *
996  * The approach here tries to preserve leading dir names.  We do so by
997  * working with four sections:
998  *   1) "prefix" directory names,
999  *   2) "suffix" directory names,
1000  *   3) inserted dir name (optional),
1001  *   4) filename.
1002  *
1003  * These sections must satisfy the following requirements:
1004  *   * Parts 1 & 2 together form an initial portion of the dir name.
1005  *   * Part 3 is specified by the caller.  (It should not contain a leading
1006  *     or trailing '/'.)
1007  *   * Part 4 forms an initial portion of the base filename.
1008  *   * The filename must be <= 99 chars to fit the ustar 'name' field.
1009  *   * Parts 2, 3, 4 together must be <= 99 chars to fit the ustar 'name' fld.
1010  *   * Part 1 must be <= 155 chars to fit the ustar 'prefix' field.
1011  *   * If the original name ends in a '/', the new name must also end in a '/'
1012  *   * Trailing '/.' sequences may be stripped.
1013  *
1014  * Note: Recall that the ustar format does not store the '/' separating
1015  * parts 1 & 2, but does store the '/' separating parts 2 & 3.
1016  */
1017 static char *
1018 build_ustar_entry_name(char *dest, const char *src, size_t src_length,
1019     const char *insert)
1020 {
1021 	const char *prefix, *prefix_end;
1022 	const char *suffix, *suffix_end;
1023 	const char *filename, *filename_end;
1024 	char *p;
1025 	int need_slash = 0; /* Was there a trailing slash? */
1026 	size_t suffix_length = 99;
1027 	int insert_length;
1028 
1029 	/* Length of additional dir element to be added. */
1030 	if (insert == NULL)
1031 		insert_length = 0;
1032 	else
1033 		/* +2 here allows for '/' before and after the insert. */
1034 		insert_length = strlen(insert) + 2;
1035 
1036 	/* Step 0: Quick bailout in a common case. */
1037 	if (src_length < 100 && insert == NULL) {
1038 		strncpy(dest, src, src_length);
1039 		dest[src_length] = '\0';
1040 		return (dest);
1041 	}
1042 
1043 	/* Step 1: Locate filename and enforce the length restriction. */
1044 	filename_end = src + src_length;
1045 	/* Remove trailing '/' chars and '/.' pairs. */
1046 	for (;;) {
1047 		if (filename_end > src && filename_end[-1] == '/') {
1048 			filename_end --;
1049 			need_slash = 1; /* Remember to restore trailing '/'. */
1050 			continue;
1051 		}
1052 		if (filename_end > src + 1 && filename_end[-1] == '.'
1053 		    && filename_end[-2] == '/') {
1054 			filename_end -= 2;
1055 			need_slash = 1; /* "foo/." will become "foo/" */
1056 			continue;
1057 		}
1058 		break;
1059 	}
1060 	if (need_slash)
1061 		suffix_length--;
1062 	/* Find start of filename. */
1063 	filename = filename_end - 1;
1064 	while ((filename > src) && (*filename != '/'))
1065 		filename --;
1066 	if ((*filename == '/') && (filename < filename_end - 1))
1067 		filename ++;
1068 	/* Adjust filename_end so that filename + insert fits in 99 chars. */
1069 	suffix_length -= insert_length;
1070 	if (filename_end > filename + suffix_length)
1071 		filename_end = filename + suffix_length;
1072 	/* Calculate max size for "suffix" section (#3 above). */
1073 	suffix_length -= filename_end - filename;
1074 
1075 	/* Step 2: Locate the "prefix" section of the dirname, including
1076 	 * trailing '/'. */
1077 	prefix = src;
1078 	prefix_end = prefix + 155;
1079 	if (prefix_end > filename)
1080 		prefix_end = filename;
1081 	while (prefix_end > prefix && *prefix_end != '/')
1082 		prefix_end--;
1083 	if ((prefix_end < filename) && (*prefix_end == '/'))
1084 		prefix_end++;
1085 
1086 	/* Step 3: Locate the "suffix" section of the dirname,
1087 	 * including trailing '/'. */
1088 	suffix = prefix_end;
1089 	suffix_end = suffix + suffix_length; /* Enforce limit. */
1090 	if (suffix_end > filename)
1091 		suffix_end = filename;
1092 	if (suffix_end < suffix)
1093 		suffix_end = suffix;
1094 	while (suffix_end > suffix && *suffix_end != '/')
1095 		suffix_end--;
1096 	if ((suffix_end < filename) && (*suffix_end == '/'))
1097 		suffix_end++;
1098 
1099 	/* Step 4: Build the new name. */
1100 	/* The OpenBSD strlcpy function is safer, but less portable. */
1101 	/* Rather than maintain two versions, just use the strncpy version. */
1102 	p = dest;
1103 	if (prefix_end > prefix) {
1104 		strncpy(p, prefix, prefix_end - prefix);
1105 		p += prefix_end - prefix;
1106 	}
1107 	if (suffix_end > suffix) {
1108 		strncpy(p, suffix, suffix_end - suffix);
1109 		p += suffix_end - suffix;
1110 	}
1111 	if (insert != NULL) {
1112 		/* Note: assume insert does not have leading or trailing '/' */
1113 		strcpy(p, insert);
1114 		p += strlen(insert);
1115 		*p++ = '/';
1116 	}
1117 	strncpy(p, filename, filename_end - filename);
1118 	p += filename_end - filename;
1119 	if (need_slash)
1120 		*p++ = '/';
1121 	*p++ = '\0';
1122 
1123 	return (dest);
1124 }
1125 
1126 /*
1127  * The ustar header for the pax extended attributes must have a
1128  * reasonable name:  SUSv3 requires 'dirname'/PaxHeader.'pid'/'filename'
1129  * where 'pid' is the PID of the archiving process.  Unfortunately,
1130  * that makes testing a pain since the output varies for each run,
1131  * so I'm sticking with the simpler 'dirname'/PaxHeader/'filename'
1132  * for now.  (Someday, I'll make this settable.  Then I can use the
1133  * SUS recommendation as default and test harnesses can override it
1134  * to get predictable results.)
1135  *
1136  * Joerg Schilling has argued that this is unnecessary because, in
1137  * practice, if the pax extended attributes get extracted as regular
1138  * files, noone is going to bother reading those attributes to
1139  * manually restore them.  Based on this, 'star' uses
1140  * /tmp/PaxHeader/'basename' as the ustar header name.  This is a
1141  * tempting argument, in part because it's simpler than the SUSv3
1142  * recommendation, but I'm not entirely convinced.  I'm also
1143  * uncomfortable with the fact that "/tmp" is a Unix-ism.
1144  *
1145  * The following routine leverages build_ustar_entry_name() above and
1146  * so is simpler than you might think.  It just needs to provide the
1147  * additional path element and handle a few pathological cases).
1148  */
1149 static char *
1150 build_pax_attribute_name(char *dest, const char *src)
1151 {
1152 	char buff[64];
1153 	const char *p;
1154 
1155 	/* Handle the null filename case. */
1156 	if (src == NULL || *src == '\0') {
1157 		strcpy(dest, "PaxHeader/blank");
1158 		return (dest);
1159 	}
1160 
1161 	/* Prune final '/' and other unwanted final elements. */
1162 	p = src + strlen(src);
1163 	for (;;) {
1164 		/* Ends in "/", remove the '/' */
1165 		if (p > src && p[-1] == '/') {
1166 			--p;
1167 			continue;
1168 		}
1169 		/* Ends in "/.", remove the '.' */
1170 		if (p > src + 1 && p[-1] == '.'
1171 		    && p[-2] == '/') {
1172 			--p;
1173 			continue;
1174 		}
1175 		break;
1176 	}
1177 
1178 	/* Pathological case: After above, there was nothing left.
1179 	 * This includes "/." "/./." "/.//./." etc. */
1180 	if (p == src) {
1181 		strcpy(dest, "/PaxHeader/rootdir");
1182 		return (dest);
1183 	}
1184 
1185 	/* Convert unadorned "." into a suitable filename. */
1186 	if (*src == '.' && p == src + 1) {
1187 		strcpy(dest, "PaxHeader/currentdir");
1188 		return (dest);
1189 	}
1190 
1191 	/*
1192 	 * TODO: Push this string into the 'pax' structure to avoid
1193 	 * recomputing it every time.  That will also open the door
1194 	 * to having clients override it.
1195 	 */
1196 #if HAVE_GETPID && 0  /* Disable this for now; see above comment. */
1197 	sprintf(buff, "PaxHeader.%d", getpid());
1198 #else
1199 	/* If the platform can't fetch the pid, don't include it. */
1200 	strcpy(buff, "PaxHeader");
1201 #endif
1202 	/* General case: build a ustar-compatible name adding "/PaxHeader/". */
1203 	build_ustar_entry_name(dest, src, p - src, buff);
1204 
1205 	return (dest);
1206 }
1207 
1208 /* Write two null blocks for the end of archive */
1209 static int
1210 archive_write_pax_finish(struct archive_write *a)
1211 {
1212 	struct pax *pax;
1213 	int r;
1214 
1215 	if (a->compressor.write == NULL)
1216 		return (ARCHIVE_OK);
1217 
1218 	pax = (struct pax *)a->format_data;
1219 	r = write_nulls(a, 512 * 2);
1220 	return (r);
1221 }
1222 
1223 static int
1224 archive_write_pax_destroy(struct archive_write *a)
1225 {
1226 	struct pax *pax;
1227 
1228 	pax = (struct pax *)a->format_data;
1229 	if (pax == NULL)
1230 		return (ARCHIVE_OK);
1231 
1232 	archive_string_free(&pax->pax_header);
1233 	free(pax);
1234 	a->format_data = NULL;
1235 	return (ARCHIVE_OK);
1236 }
1237 
1238 static int
1239 archive_write_pax_finish_entry(struct archive_write *a)
1240 {
1241 	struct pax *pax;
1242 	int ret;
1243 
1244 	pax = (struct pax *)a->format_data;
1245 	ret = write_nulls(a, pax->entry_bytes_remaining + pax->entry_padding);
1246 	pax->entry_bytes_remaining = pax->entry_padding = 0;
1247 	return (ret);
1248 }
1249 
1250 static int
1251 write_nulls(struct archive_write *a, size_t padding)
1252 {
1253 	int ret, to_write;
1254 
1255 	while (padding > 0) {
1256 		to_write = padding < a->null_length ? padding : a->null_length;
1257 		ret = (a->compressor.write)(a, a->nulls, to_write);
1258 		if (ret != ARCHIVE_OK)
1259 			return (ret);
1260 		padding -= to_write;
1261 	}
1262 	return (ARCHIVE_OK);
1263 }
1264 
1265 static ssize_t
1266 archive_write_pax_data(struct archive_write *a, const void *buff, size_t s)
1267 {
1268 	struct pax *pax;
1269 	int ret;
1270 
1271 	pax = (struct pax *)a->format_data;
1272 	if (s > pax->entry_bytes_remaining)
1273 		s = pax->entry_bytes_remaining;
1274 
1275 	ret = (a->compressor.write)(a, buff, s);
1276 	pax->entry_bytes_remaining -= s;
1277 	if (ret == ARCHIVE_OK)
1278 		return (s);
1279 	else
1280 		return (ret);
1281 }
1282 
1283 static int
1284 has_non_ASCII(const wchar_t *wp)
1285 {
1286 	if (wp == NULL)
1287 		return (1);
1288 	while (*wp != L'\0' && *wp < 128)
1289 		wp++;
1290 	return (*wp != L'\0');
1291 }
1292 
1293 /*
1294  * Used by extended attribute support; encodes the name
1295  * so that there will be no '=' characters in the result.
1296  */
1297 static char *
1298 url_encode(const char *in)
1299 {
1300 	const char *s;
1301 	char *d;
1302 	int out_len = 0;
1303 	char *out;
1304 
1305 	for (s = in; *s != '\0'; s++) {
1306 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=')
1307 			out_len += 3;
1308 		else
1309 			out_len++;
1310 	}
1311 
1312 	out = (char *)malloc(out_len + 1);
1313 	if (out == NULL)
1314 		return (NULL);
1315 
1316 	for (s = in, d = out; *s != '\0'; s++) {
1317 		/* encode any non-printable ASCII character or '%' or '=' */
1318 		if (*s < 33 || *s > 126 || *s == '%' || *s == '=') {
1319 			/* URL encoding is '%' followed by two hex digits */
1320 			*d++ = '%';
1321 			*d++ = "0123456789ABCDEF"[0x0f & (*s >> 4)];
1322 			*d++ = "0123456789ABCDEF"[0x0f & *s];
1323 		} else {
1324 			*d++ = *s;
1325 		}
1326 	}
1327 	*d = '\0';
1328 	return (out);
1329 }
1330 
1331 /*
1332  * Encode a sequence of bytes into a C string using base-64 encoding.
1333  *
1334  * Returns a null-terminated C string allocated with malloc(); caller
1335  * is responsible for freeing the result.
1336  */
1337 static char *
1338 base64_encode(const char *s, size_t len)
1339 {
1340 	static const char digits[64] =
1341 	    { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O',
1342 	      'P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d',
1343 	      'e','f','g','h','i','j','k','l','m','n','o','p','q','r','s',
1344 	      't','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
1345 	      '8','9','+','/' };
1346 	int v;
1347 	char *d, *out;
1348 
1349 	/* 3 bytes becomes 4 chars, but round up and allow for trailing NUL */
1350 	out = (char *)malloc((len * 4 + 2) / 3 + 1);
1351 	if (out == NULL)
1352 		return (NULL);
1353 	d = out;
1354 
1355 	/* Convert each group of 3 bytes into 4 characters. */
1356 	while (len >= 3) {
1357 		v = (((int)s[0] << 16) & 0xff0000)
1358 		    | (((int)s[1] << 8) & 0xff00)
1359 		    | (((int)s[2]) & 0x00ff);
1360 		s += 3;
1361 		len -= 3;
1362 		*d++ = digits[(v >> 18) & 0x3f];
1363 		*d++ = digits[(v >> 12) & 0x3f];
1364 		*d++ = digits[(v >> 6) & 0x3f];
1365 		*d++ = digits[(v) & 0x3f];
1366 	}
1367 	/* Handle final group of 1 byte (2 chars) or 2 bytes (3 chars). */
1368 	switch (len) {
1369 	case 0: break;
1370 	case 1:
1371 		v = (((int)s[0] << 16) & 0xff0000);
1372 		*d++ = digits[(v >> 18) & 0x3f];
1373 		*d++ = digits[(v >> 12) & 0x3f];
1374 		break;
1375 	case 2:
1376 		v = (((int)s[0] << 16) & 0xff0000)
1377 		    | (((int)s[1] << 8) & 0xff00);
1378 		*d++ = digits[(v >> 18) & 0x3f];
1379 		*d++ = digits[(v >> 12) & 0x3f];
1380 		*d++ = digits[(v >> 6) & 0x3f];
1381 		break;
1382 	}
1383 	/* Add trailing NUL character so output is a valid C string. */
1384 	*d++ = '\0';
1385 	return (out);
1386 }
1387