1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * Copyright (c) 2011-2012 Michihiro NAKAJIMA
4  * Copyright (c) 2016 Martin Matuska
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "archive_platform.h"
29 __FBSDID("$FreeBSD: head/lib/libarchive/archive_read_support_format_tar.c 201161 2009-12-29 05:44:39Z kientzle $");
30 
31 #ifdef HAVE_ERRNO_H
32 #include <errno.h>
33 #endif
34 #include <stddef.h>
35 #ifdef HAVE_STDLIB_H
36 #include <stdlib.h>
37 #endif
38 #ifdef HAVE_STRING_H
39 #include <string.h>
40 #endif
41 
42 #include "archive.h"
43 #include "archive_acl_private.h" /* For ACL parsing routines. */
44 #include "archive_entry.h"
45 #include "archive_entry_locale.h"
46 #include "archive_private.h"
47 #include "archive_read_private.h"
48 
49 #define tar_min(a,b) ((a) < (b) ? (a) : (b))
50 
51 /*
52  * Layout of POSIX 'ustar' tar header.
53  */
54 struct archive_entry_header_ustar {
55 	char	name[100];
56 	char	mode[8];
57 	char	uid[8];
58 	char	gid[8];
59 	char	size[12];
60 	char	mtime[12];
61 	char	checksum[8];
62 	char	typeflag[1];
63 	char	linkname[100];	/* "old format" header ends here */
64 	char	magic[6];	/* For POSIX: "ustar\0" */
65 	char	version[2];	/* For POSIX: "00" */
66 	char	uname[32];
67 	char	gname[32];
68 	char	rdevmajor[8];
69 	char	rdevminor[8];
70 	char	prefix[155];
71 };
72 
73 /*
74  * Structure of GNU tar header
75  */
76 struct gnu_sparse {
77 	char	offset[12];
78 	char	numbytes[12];
79 };
80 
81 struct archive_entry_header_gnutar {
82 	char	name[100];
83 	char	mode[8];
84 	char	uid[8];
85 	char	gid[8];
86 	char	size[12];
87 	char	mtime[12];
88 	char	checksum[8];
89 	char	typeflag[1];
90 	char	linkname[100];
91 	char	magic[8];  /* "ustar  \0" (note blank/blank/null at end) */
92 	char	uname[32];
93 	char	gname[32];
94 	char	rdevmajor[8];
95 	char	rdevminor[8];
96 	char	atime[12];
97 	char	ctime[12];
98 	char	offset[12];
99 	char	longnames[4];
100 	char	unused[1];
101 	struct gnu_sparse sparse[4];
102 	char	isextended[1];
103 	char	realsize[12];
104 	/*
105 	 * Old GNU format doesn't use POSIX 'prefix' field; they use
106 	 * the 'L' (longname) entry instead.
107 	 */
108 };
109 
110 /*
111  * Data specific to this format.
112  */
113 struct sparse_block {
114 	struct sparse_block	*next;
115 	int64_t	offset;
116 	int64_t	remaining;
117 	int hole;
118 };
119 
120 struct tar {
121 	struct archive_string	 acl_text;
122 	struct archive_string	 entry_pathname;
123 	/* For "GNU.sparse.name" and other similar path extensions. */
124 	struct archive_string	 entry_pathname_override;
125 	struct archive_string	 entry_linkpath;
126 	struct archive_string	 entry_uname;
127 	struct archive_string	 entry_gname;
128 	struct archive_string	 longlink;
129 	struct archive_string	 longname;
130 	struct archive_string	 pax_header;
131 	struct archive_string	 pax_global;
132 	struct archive_string	 line;
133 	int			 pax_hdrcharset_binary;
134 	int			 header_recursion_depth;
135 	int64_t			 entry_bytes_remaining;
136 	int64_t			 entry_offset;
137 	int64_t			 entry_padding;
138 	int64_t 		 entry_bytes_unconsumed;
139 	int64_t			 realsize;
140 	int			 sparse_allowed;
141 	struct sparse_block	*sparse_list;
142 	struct sparse_block	*sparse_last;
143 	int64_t			 sparse_offset;
144 	int64_t			 sparse_numbytes;
145 	int			 sparse_gnu_major;
146 	int			 sparse_gnu_minor;
147 	char			 sparse_gnu_pending;
148 
149 	struct archive_string	 localname;
150 	struct archive_string_conv *opt_sconv;
151 	struct archive_string_conv *sconv;
152 	struct archive_string_conv *sconv_acl;
153 	struct archive_string_conv *sconv_default;
154 	int			 init_default_conversion;
155 	int			 compat_2x;
156 	int			 process_mac_extensions;
157 	int			 read_concatenated_archives;
158 	int			 realsize_override;
159 };
160 
161 static int	archive_block_is_null(const char *p);
162 static char	*base64_decode(const char *, size_t, size_t *);
163 static int	gnu_add_sparse_entry(struct archive_read *, struct tar *,
164 		    int64_t offset, int64_t remaining);
165 
166 static void	gnu_clear_sparse_list(struct tar *);
167 static int	gnu_sparse_old_read(struct archive_read *, struct tar *,
168 		    const struct archive_entry_header_gnutar *header, size_t *);
169 static int	gnu_sparse_old_parse(struct archive_read *, struct tar *,
170 		    const struct gnu_sparse *sparse, int length);
171 static int	gnu_sparse_01_parse(struct archive_read *, struct tar *,
172 		    const char *);
173 static ssize_t	gnu_sparse_10_read(struct archive_read *, struct tar *,
174 			size_t *);
175 static int	header_Solaris_ACL(struct archive_read *,  struct tar *,
176 		    struct archive_entry *, const void *, size_t *);
177 static int	header_common(struct archive_read *,  struct tar *,
178 		    struct archive_entry *, const void *);
179 static int	header_old_tar(struct archive_read *, struct tar *,
180 		    struct archive_entry *, const void *);
181 static int	header_pax_extensions(struct archive_read *, struct tar *,
182 		    struct archive_entry *, const void *, size_t *);
183 static int	header_pax_global(struct archive_read *, struct tar *,
184 		    struct archive_entry *, const void *h, size_t *);
185 static int	header_longlink(struct archive_read *, struct tar *,
186 		    struct archive_entry *, const void *h, size_t *);
187 static int	header_longname(struct archive_read *, struct tar *,
188 		    struct archive_entry *, const void *h, size_t *);
189 static int	read_mac_metadata_blob(struct archive_read *, struct tar *,
190 		    struct archive_entry *, const void *h, size_t *);
191 static int	header_volume(struct archive_read *, struct tar *,
192 		    struct archive_entry *, const void *h, size_t *);
193 static int	header_ustar(struct archive_read *, struct tar *,
194 		    struct archive_entry *, const void *h);
195 static int	header_gnutar(struct archive_read *, struct tar *,
196 		    struct archive_entry *, const void *h, size_t *);
197 static int	archive_read_format_tar_bid(struct archive_read *, int);
198 static int	archive_read_format_tar_options(struct archive_read *,
199 		    const char *, const char *);
200 static int	archive_read_format_tar_cleanup(struct archive_read *);
201 static int	archive_read_format_tar_read_data(struct archive_read *a,
202 		    const void **buff, size_t *size, int64_t *offset);
203 static int	archive_read_format_tar_skip(struct archive_read *a);
204 static int	archive_read_format_tar_read_header(struct archive_read *,
205 		    struct archive_entry *);
206 static int	checksum(struct archive_read *, const void *);
207 static int 	pax_attribute(struct archive_read *, struct tar *,
208 		    struct archive_entry *, const char *key, const char *value,
209 		    size_t value_length);
210 static int	pax_attribute_acl(struct archive_read *, struct tar *,
211 		    struct archive_entry *, const char *, int);
212 static int	pax_attribute_xattr(struct archive_entry *, const char *,
213 		    const char *);
214 static int 	pax_header(struct archive_read *, struct tar *,
215 		    struct archive_entry *, struct archive_string *);
216 static void	pax_time(const char *, int64_t *sec, long *nanos);
217 static ssize_t	readline(struct archive_read *, struct tar *, const char **,
218 		    ssize_t limit, size_t *);
219 static int	read_body_to_string(struct archive_read *, struct tar *,
220 		    struct archive_string *, const void *h, size_t *);
221 static int	solaris_sparse_parse(struct archive_read *, struct tar *,
222 		    struct archive_entry *, const char *);
223 static int64_t	tar_atol(const char *, size_t);
224 static int64_t	tar_atol10(const char *, size_t);
225 static int64_t	tar_atol256(const char *, size_t);
226 static int64_t	tar_atol8(const char *, size_t);
227 static int	tar_read_header(struct archive_read *, struct tar *,
228 		    struct archive_entry *, size_t *);
229 static int	tohex(int c);
230 static char	*url_decode(const char *);
231 static void	tar_flush_unconsumed(struct archive_read *, size_t *);
232 
233 
234 int
235 archive_read_support_format_gnutar(struct archive *a)
236 {
237 	archive_check_magic(a, ARCHIVE_READ_MAGIC,
238 	    ARCHIVE_STATE_NEW, "archive_read_support_format_gnutar");
239 	return (archive_read_support_format_tar(a));
240 }
241 
242 
243 int
244 archive_read_support_format_tar(struct archive *_a)
245 {
246 	struct archive_read *a = (struct archive_read *)_a;
247 	struct tar *tar;
248 	int r;
249 
250 	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
251 	    ARCHIVE_STATE_NEW, "archive_read_support_format_tar");
252 
253 	tar = (struct tar *)calloc(1, sizeof(*tar));
254 	if (tar == NULL) {
255 		archive_set_error(&a->archive, ENOMEM,
256 		    "Can't allocate tar data");
257 		return (ARCHIVE_FATAL);
258 	}
259 #ifdef HAVE_COPYFILE_H
260 	/* Set this by default on Mac OS. */
261 	tar->process_mac_extensions = 1;
262 #endif
263 
264 	r = __archive_read_register_format(a, tar, "tar",
265 	    archive_read_format_tar_bid,
266 	    archive_read_format_tar_options,
267 	    archive_read_format_tar_read_header,
268 	    archive_read_format_tar_read_data,
269 	    archive_read_format_tar_skip,
270 	    NULL,
271 	    archive_read_format_tar_cleanup,
272 	    NULL,
273 	    NULL);
274 
275 	if (r != ARCHIVE_OK)
276 		free(tar);
277 	return (ARCHIVE_OK);
278 }
279 
280 static int
281 archive_read_format_tar_cleanup(struct archive_read *a)
282 {
283 	struct tar *tar;
284 
285 	tar = (struct tar *)(a->format->data);
286 	gnu_clear_sparse_list(tar);
287 	archive_string_free(&tar->acl_text);
288 	archive_string_free(&tar->entry_pathname);
289 	archive_string_free(&tar->entry_pathname_override);
290 	archive_string_free(&tar->entry_linkpath);
291 	archive_string_free(&tar->entry_uname);
292 	archive_string_free(&tar->entry_gname);
293 	archive_string_free(&tar->line);
294 	archive_string_free(&tar->pax_global);
295 	archive_string_free(&tar->pax_header);
296 	archive_string_free(&tar->longname);
297 	archive_string_free(&tar->longlink);
298 	archive_string_free(&tar->localname);
299 	free(tar);
300 	(a->format->data) = NULL;
301 	return (ARCHIVE_OK);
302 }
303 
304 /*
305  * Validate number field
306  *
307  * This has to be pretty lenient in order to accommodate the enormous
308  * variety of tar writers in the world:
309  *  = POSIX (IEEE Std 1003.1-1988) ustar requires octal values with leading
310  *    zeros and allows fields to be terminated with space or null characters
311  *  = Many writers use different termination (in particular, libarchive
312  *    omits terminator bytes to squeeze one or two more digits)
313  *  = Many writers pad with space and omit leading zeros
314  *  = GNU tar and star write base-256 values if numbers are too
315  *    big to be represented in octal
316  *
317  *  Examples of specific tar headers that we should support:
318  *  = Perl Archive::Tar terminates uid, gid, devminor and devmajor with two
319  *    null bytes, pads size with spaces and other numeric fields with zeroes
320  *  = plexus-archiver prior to 2.6.3 (before switching to commons-compress)
321  *    may have uid and gid fields filled with spaces without any octal digits
322  *    at all and pads all numeric fields with spaces
323  *
324  * This should tolerate all variants in use.  It will reject a field
325  * where the writer just left garbage after a trailing NUL.
326  */
327 static int
328 validate_number_field(const char* p_field, size_t i_size)
329 {
330 	unsigned char marker = (unsigned char)p_field[0];
331 	if (marker == 128 || marker == 255 || marker == 0) {
332 		/* Base-256 marker, there's nothing we can check. */
333 		return 1;
334 	} else {
335 		/* Must be octal */
336 		size_t i = 0;
337 		/* Skip any leading spaces */
338 		while (i < i_size && p_field[i] == ' ') {
339 			++i;
340 		}
341 		/* Skip octal digits. */
342 		while (i < i_size && p_field[i] >= '0' && p_field[i] <= '7') {
343 			++i;
344 		}
345 		/* Any remaining characters must be space or NUL padding. */
346 		while (i < i_size) {
347 			if (p_field[i] != ' ' && p_field[i] != 0) {
348 				return 0;
349 			}
350 			++i;
351 		}
352 		return 1;
353 	}
354 }
355 
356 static int
357 archive_read_format_tar_bid(struct archive_read *a, int best_bid)
358 {
359 	int bid;
360 	const char *h;
361 	const struct archive_entry_header_ustar *header;
362 
363 	(void)best_bid; /* UNUSED */
364 
365 	bid = 0;
366 
367 	/* Now let's look at the actual header and see if it matches. */
368 	h = __archive_read_ahead(a, 512, NULL);
369 	if (h == NULL)
370 		return (-1);
371 
372 	/* If it's an end-of-archive mark, we can handle it. */
373 	if (h[0] == 0 && archive_block_is_null(h)) {
374 		/*
375 		 * Usually, I bid the number of bits verified, but
376 		 * in this case, 4096 seems excessive so I picked 10 as
377 		 * an arbitrary but reasonable-seeming value.
378 		 */
379 		return (10);
380 	}
381 
382 	/* If it's not an end-of-archive mark, it must have a valid checksum.*/
383 	if (!checksum(a, h))
384 		return (0);
385 	bid += 48;  /* Checksum is usually 6 octal digits. */
386 
387 	header = (const struct archive_entry_header_ustar *)h;
388 
389 	/* Recognize POSIX formats. */
390 	if ((memcmp(header->magic, "ustar\0", 6) == 0)
391 	    && (memcmp(header->version, "00", 2) == 0))
392 		bid += 56;
393 
394 	/* Recognize GNU tar format. */
395 	if ((memcmp(header->magic, "ustar ", 6) == 0)
396 	    && (memcmp(header->version, " \0", 2) == 0))
397 		bid += 56;
398 
399 	/* Type flag must be null, digit or A-Z, a-z. */
400 	if (header->typeflag[0] != 0 &&
401 	    !( header->typeflag[0] >= '0' && header->typeflag[0] <= '9') &&
402 	    !( header->typeflag[0] >= 'A' && header->typeflag[0] <= 'Z') &&
403 	    !( header->typeflag[0] >= 'a' && header->typeflag[0] <= 'z') )
404 		return (0);
405 	bid += 2;  /* 6 bits of variation in an 8-bit field leaves 2 bits. */
406 
407 	/*
408 	 * Check format of mode/uid/gid/mtime/size/rdevmajor/rdevminor fields.
409 	 */
410 	if (bid > 0 && (
411 	    validate_number_field(header->mode, sizeof(header->mode)) == 0
412 	    || validate_number_field(header->uid, sizeof(header->uid)) == 0
413 	    || validate_number_field(header->gid, sizeof(header->gid)) == 0
414 	    || validate_number_field(header->mtime, sizeof(header->mtime)) == 0
415 	    || validate_number_field(header->size, sizeof(header->size)) == 0
416 	    || validate_number_field(header->rdevmajor, sizeof(header->rdevmajor)) == 0
417 	    || validate_number_field(header->rdevminor, sizeof(header->rdevminor)) == 0)) {
418 		bid = 0;
419 	}
420 
421 	return (bid);
422 }
423 
424 static int
425 archive_read_format_tar_options(struct archive_read *a,
426     const char *key, const char *val)
427 {
428 	struct tar *tar;
429 	int ret = ARCHIVE_FAILED;
430 
431 	tar = (struct tar *)(a->format->data);
432 	if (strcmp(key, "compat-2x")  == 0) {
433 		/* Handle UTF-8 filenames as libarchive 2.x */
434 		tar->compat_2x = (val != NULL && val[0] != 0);
435 		tar->init_default_conversion = tar->compat_2x;
436 		return (ARCHIVE_OK);
437 	} else if (strcmp(key, "hdrcharset")  == 0) {
438 		if (val == NULL || val[0] == 0)
439 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
440 			    "tar: hdrcharset option needs a character-set name");
441 		else {
442 			tar->opt_sconv =
443 			    archive_string_conversion_from_charset(
444 				&a->archive, val, 0);
445 			if (tar->opt_sconv != NULL)
446 				ret = ARCHIVE_OK;
447 			else
448 				ret = ARCHIVE_FATAL;
449 		}
450 		return (ret);
451 	} else if (strcmp(key, "mac-ext") == 0) {
452 		tar->process_mac_extensions = (val != NULL && val[0] != 0);
453 		return (ARCHIVE_OK);
454 	} else if (strcmp(key, "read_concatenated_archives") == 0) {
455 		tar->read_concatenated_archives = (val != NULL && val[0] != 0);
456 		return (ARCHIVE_OK);
457 	}
458 
459 	/* Note: The "warn" return is just to inform the options
460 	 * supervisor that we didn't handle it.  It will generate
461 	 * a suitable error if no one used this option. */
462 	return (ARCHIVE_WARN);
463 }
464 
465 /* utility function- this exists to centralize the logic of tracking
466  * how much unconsumed data we have floating around, and to consume
467  * anything outstanding since we're going to do read_aheads
468  */
469 static void
470 tar_flush_unconsumed(struct archive_read *a, size_t *unconsumed)
471 {
472 	if (*unconsumed) {
473 /*
474 		void *data = (void *)__archive_read_ahead(a, *unconsumed, NULL);
475 		 * this block of code is to poison claimed unconsumed space, ensuring
476 		 * things break if it is in use still.
477 		 * currently it WILL break things, so enable it only for debugging this issue
478 		if (data) {
479 			memset(data, 0xff, *unconsumed);
480 		}
481 */
482 		__archive_read_consume(a, *unconsumed);
483 		*unconsumed = 0;
484 	}
485 }
486 
487 /*
488  * The function invoked by archive_read_next_header().  This
489  * just sets up a few things and then calls the internal
490  * tar_read_header() function below.
491  */
492 static int
493 archive_read_format_tar_read_header(struct archive_read *a,
494     struct archive_entry *entry)
495 {
496 	/*
497 	 * When converting tar archives to cpio archives, it is
498 	 * essential that each distinct file have a distinct inode
499 	 * number.  To simplify this, we keep a static count here to
500 	 * assign fake dev/inode numbers to each tar entry.  Note that
501 	 * pax format archives may overwrite this with something more
502 	 * useful.
503 	 *
504 	 * Ideally, we would track every file read from the archive so
505 	 * that we could assign the same dev/ino pair to hardlinks,
506 	 * but the memory required to store a complete lookup table is
507 	 * probably not worthwhile just to support the relatively
508 	 * obscure tar->cpio conversion case.
509 	 */
510 	static int default_inode;
511 	static int default_dev;
512 	struct tar *tar;
513 	const char *p;
514 	const wchar_t *wp;
515 	int r;
516 	size_t l, unconsumed = 0;
517 
518 	/* Assign default device/inode values. */
519 	archive_entry_set_dev(entry, 1 + default_dev); /* Don't use zero. */
520 	archive_entry_set_ino(entry, ++default_inode); /* Don't use zero. */
521 	/* Limit generated st_ino number to 16 bits. */
522 	if (default_inode >= 0xffff) {
523 		++default_dev;
524 		default_inode = 0;
525 	}
526 
527 	tar = (struct tar *)(a->format->data);
528 	tar->entry_offset = 0;
529 	gnu_clear_sparse_list(tar);
530 	tar->realsize = -1; /* Mark this as "unset" */
531 	tar->realsize_override = 0;
532 
533 	/* Setup default string conversion. */
534 	tar->sconv = tar->opt_sconv;
535 	if (tar->sconv == NULL) {
536 		if (!tar->init_default_conversion) {
537 			tar->sconv_default =
538 			    archive_string_default_conversion_for_read(&(a->archive));
539 			tar->init_default_conversion = 1;
540 		}
541 		tar->sconv = tar->sconv_default;
542 	}
543 
544 	r = tar_read_header(a, tar, entry, &unconsumed);
545 
546 	tar_flush_unconsumed(a, &unconsumed);
547 
548 	/*
549 	 * "non-sparse" files are really just sparse files with
550 	 * a single block.
551 	 */
552 	if (tar->sparse_list == NULL) {
553 		if (gnu_add_sparse_entry(a, tar, 0, tar->entry_bytes_remaining)
554 		    != ARCHIVE_OK)
555 			return (ARCHIVE_FATAL);
556 	} else {
557 		struct sparse_block *sb;
558 
559 		for (sb = tar->sparse_list; sb != NULL; sb = sb->next) {
560 			if (!sb->hole)
561 				archive_entry_sparse_add_entry(entry,
562 				    sb->offset, sb->remaining);
563 		}
564 	}
565 
566 	if (r == ARCHIVE_OK && archive_entry_filetype(entry) == AE_IFREG) {
567 		/*
568 		 * "Regular" entry with trailing '/' is really
569 		 * directory: This is needed for certain old tar
570 		 * variants and even for some broken newer ones.
571 		 */
572 		if ((wp = archive_entry_pathname_w(entry)) != NULL) {
573 			l = wcslen(wp);
574 			if (l > 0 && wp[l - 1] == L'/') {
575 				archive_entry_set_filetype(entry, AE_IFDIR);
576 			}
577 		} else if ((p = archive_entry_pathname(entry)) != NULL) {
578 			l = strlen(p);
579 			if (l > 0 && p[l - 1] == '/') {
580 				archive_entry_set_filetype(entry, AE_IFDIR);
581 			}
582 		}
583 	}
584 	return (r);
585 }
586 
587 static int
588 archive_read_format_tar_read_data(struct archive_read *a,
589     const void **buff, size_t *size, int64_t *offset)
590 {
591 	ssize_t bytes_read;
592 	struct tar *tar;
593 	struct sparse_block *p;
594 
595 	tar = (struct tar *)(a->format->data);
596 
597 	for (;;) {
598 		/* Remove exhausted entries from sparse list. */
599 		while (tar->sparse_list != NULL &&
600 		    tar->sparse_list->remaining == 0) {
601 			p = tar->sparse_list;
602 			tar->sparse_list = p->next;
603 			free(p);
604 		}
605 
606 		if (tar->entry_bytes_unconsumed) {
607 			__archive_read_consume(a, tar->entry_bytes_unconsumed);
608 			tar->entry_bytes_unconsumed = 0;
609 		}
610 
611 		/* If we're at end of file, return EOF. */
612 		if (tar->sparse_list == NULL ||
613 		    tar->entry_bytes_remaining == 0) {
614 			if (__archive_read_consume(a, tar->entry_padding) < 0)
615 				return (ARCHIVE_FATAL);
616 			tar->entry_padding = 0;
617 			*buff = NULL;
618 			*size = 0;
619 			*offset = tar->realsize;
620 			return (ARCHIVE_EOF);
621 		}
622 
623 		*buff = __archive_read_ahead(a, 1, &bytes_read);
624 		if (bytes_read < 0)
625 			return (ARCHIVE_FATAL);
626 		if (*buff == NULL) {
627 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
628 			    "Truncated tar archive");
629 			return (ARCHIVE_FATAL);
630 		}
631 		if (bytes_read > tar->entry_bytes_remaining)
632 			bytes_read = (ssize_t)tar->entry_bytes_remaining;
633 		/* Don't read more than is available in the
634 		 * current sparse block. */
635 		if (tar->sparse_list->remaining < bytes_read)
636 			bytes_read = (ssize_t)tar->sparse_list->remaining;
637 		*size = bytes_read;
638 		*offset = tar->sparse_list->offset;
639 		tar->sparse_list->remaining -= bytes_read;
640 		tar->sparse_list->offset += bytes_read;
641 		tar->entry_bytes_remaining -= bytes_read;
642 		tar->entry_bytes_unconsumed = bytes_read;
643 
644 		if (!tar->sparse_list->hole)
645 			return (ARCHIVE_OK);
646 		/* Current is hole data and skip this. */
647 	}
648 }
649 
650 static int
651 archive_read_format_tar_skip(struct archive_read *a)
652 {
653 	int64_t bytes_skipped;
654 	int64_t request;
655 	struct sparse_block *p;
656 	struct tar* tar;
657 
658 	tar = (struct tar *)(a->format->data);
659 
660 	/* Do not consume the hole of a sparse file. */
661 	request = 0;
662 	for (p = tar->sparse_list; p != NULL; p = p->next) {
663 		if (!p->hole) {
664 			if (p->remaining >= INT64_MAX - request) {
665 				return ARCHIVE_FATAL;
666 			}
667 			request += p->remaining;
668 		}
669 	}
670 	if (request > tar->entry_bytes_remaining)
671 		request = tar->entry_bytes_remaining;
672 	request += tar->entry_padding + tar->entry_bytes_unconsumed;
673 
674 	bytes_skipped = __archive_read_consume(a, request);
675 	if (bytes_skipped < 0)
676 		return (ARCHIVE_FATAL);
677 
678 	tar->entry_bytes_remaining = 0;
679 	tar->entry_bytes_unconsumed = 0;
680 	tar->entry_padding = 0;
681 
682 	/* Free the sparse list. */
683 	gnu_clear_sparse_list(tar);
684 
685 	return (ARCHIVE_OK);
686 }
687 
688 /*
689  * This function recursively interprets all of the headers associated
690  * with a single entry.
691  */
692 static int
693 tar_read_header(struct archive_read *a, struct tar *tar,
694     struct archive_entry *entry, size_t *unconsumed)
695 {
696 	ssize_t bytes;
697 	int err;
698 	const char *h;
699 	const struct archive_entry_header_ustar *header;
700 	const struct archive_entry_header_gnutar *gnuheader;
701 
702 	/* Loop until we find a workable header record. */
703 	for (;;) {
704 		tar_flush_unconsumed(a, unconsumed);
705 
706 		/* Read 512-byte header record */
707 		h = __archive_read_ahead(a, 512, &bytes);
708 		if (bytes < 0)
709 			return ((int)bytes);
710 		if (bytes == 0) { /* EOF at a block boundary. */
711 			/* Some writers do omit the block of nulls. <sigh> */
712 			return (ARCHIVE_EOF);
713 		}
714 		if (bytes < 512) {  /* Short block at EOF; this is bad. */
715 			archive_set_error(&a->archive,
716 			    ARCHIVE_ERRNO_FILE_FORMAT,
717 			    "Truncated tar archive");
718 			return (ARCHIVE_FATAL);
719 		}
720 		*unconsumed = 512;
721 
722 		/* Header is workable if it's not an end-of-archive mark. */
723 		if (h[0] != 0 || !archive_block_is_null(h))
724 			break;
725 
726 		/* Ensure format is set for archives with only null blocks. */
727 		if (a->archive.archive_format_name == NULL) {
728 			a->archive.archive_format = ARCHIVE_FORMAT_TAR;
729 			a->archive.archive_format_name = "tar";
730 		}
731 
732 		if (!tar->read_concatenated_archives) {
733 			/* Try to consume a second all-null record, as well. */
734 			tar_flush_unconsumed(a, unconsumed);
735 			h = __archive_read_ahead(a, 512, NULL);
736 			if (h != NULL && h[0] == 0 && archive_block_is_null(h))
737 				__archive_read_consume(a, 512);
738 			archive_clear_error(&a->archive);
739 			return (ARCHIVE_EOF);
740 		}
741 
742 		/*
743 		 * We're reading concatenated archives, ignore this block and
744 		 * loop to get the next.
745 		 */
746 	}
747 
748 	/*
749 	 * Note: If the checksum fails and we return ARCHIVE_RETRY,
750 	 * then the client is likely to just retry.  This is a very
751 	 * crude way to search for the next valid header!
752 	 *
753 	 * TODO: Improve this by implementing a real header scan.
754 	 */
755 	if (!checksum(a, h)) {
756 		tar_flush_unconsumed(a, unconsumed);
757 		archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
758 		return (ARCHIVE_RETRY); /* Retryable: Invalid header */
759 	}
760 
761 	if (++tar->header_recursion_depth > 32) {
762 		tar_flush_unconsumed(a, unconsumed);
763 		archive_set_error(&a->archive, EINVAL, "Too many special headers");
764 		return (ARCHIVE_WARN);
765 	}
766 
767 	/* Determine the format variant. */
768 	header = (const struct archive_entry_header_ustar *)h;
769 
770 	switch(header->typeflag[0]) {
771 	case 'A': /* Solaris tar ACL */
772 		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
773 		a->archive.archive_format_name = "Solaris tar";
774 		err = header_Solaris_ACL(a, tar, entry, h, unconsumed);
775 		break;
776 	case 'g': /* POSIX-standard 'g' header. */
777 		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
778 		a->archive.archive_format_name = "POSIX pax interchange format";
779 		err = header_pax_global(a, tar, entry, h, unconsumed);
780 		if (err == ARCHIVE_EOF)
781 			return (err);
782 		break;
783 	case 'K': /* Long link name (GNU tar, others) */
784 		err = header_longlink(a, tar, entry, h, unconsumed);
785 		break;
786 	case 'L': /* Long filename (GNU tar, others) */
787 		err = header_longname(a, tar, entry, h, unconsumed);
788 		break;
789 	case 'V': /* GNU volume header */
790 		err = header_volume(a, tar, entry, h, unconsumed);
791 		break;
792 	case 'X': /* Used by SUN tar; same as 'x'. */
793 		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
794 		a->archive.archive_format_name =
795 		    "POSIX pax interchange format (Sun variant)";
796 		err = header_pax_extensions(a, tar, entry, h, unconsumed);
797 		break;
798 	case 'x': /* POSIX-standard 'x' header. */
799 		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
800 		a->archive.archive_format_name = "POSIX pax interchange format";
801 		err = header_pax_extensions(a, tar, entry, h, unconsumed);
802 		break;
803 	default:
804 		gnuheader = (const struct archive_entry_header_gnutar *)h;
805 		if (memcmp(gnuheader->magic, "ustar  \0", 8) == 0) {
806 			a->archive.archive_format = ARCHIVE_FORMAT_TAR_GNUTAR;
807 			a->archive.archive_format_name = "GNU tar format";
808 			err = header_gnutar(a, tar, entry, h, unconsumed);
809 		} else if (memcmp(header->magic, "ustar", 5) == 0) {
810 			if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
811 				a->archive.archive_format = ARCHIVE_FORMAT_TAR_USTAR;
812 				a->archive.archive_format_name = "POSIX ustar format";
813 			}
814 			err = header_ustar(a, tar, entry, h);
815 		} else {
816 			a->archive.archive_format = ARCHIVE_FORMAT_TAR;
817 			a->archive.archive_format_name = "tar (non-POSIX)";
818 			err = header_old_tar(a, tar, entry, h);
819 		}
820 	}
821 	if (err == ARCHIVE_FATAL)
822 		return (err);
823 
824 	tar_flush_unconsumed(a, unconsumed);
825 
826 	h = NULL;
827 	header = NULL;
828 
829 	--tar->header_recursion_depth;
830 	/* Yuck.  Apple's design here ends up storing long pathname
831 	 * extensions for both the AppleDouble extension entry and the
832 	 * regular entry.
833 	 */
834 	if ((err == ARCHIVE_WARN || err == ARCHIVE_OK) &&
835 	    tar->header_recursion_depth == 0 &&
836 	    tar->process_mac_extensions) {
837 		int err2 = read_mac_metadata_blob(a, tar, entry, h, unconsumed);
838 		if (err2 < err)
839 			err = err2;
840 	}
841 
842 	/* We return warnings or success as-is.  Anything else is fatal. */
843 	if (err == ARCHIVE_WARN || err == ARCHIVE_OK) {
844 		if (tar->sparse_gnu_pending) {
845 			if (tar->sparse_gnu_major == 1 &&
846 			    tar->sparse_gnu_minor == 0) {
847 				ssize_t bytes_read;
848 
849 				tar->sparse_gnu_pending = 0;
850 				/* Read initial sparse map. */
851 				bytes_read = gnu_sparse_10_read(a, tar, unconsumed);
852 				if (bytes_read < 0)
853 					return ((int)bytes_read);
854 				tar->entry_bytes_remaining -= bytes_read;
855 			} else {
856 				archive_set_error(&a->archive,
857 				    ARCHIVE_ERRNO_MISC,
858 				    "Unrecognized GNU sparse file format");
859 				return (ARCHIVE_WARN);
860 			}
861 			tar->sparse_gnu_pending = 0;
862 		}
863 		return (err);
864 	}
865 	if (err == ARCHIVE_EOF)
866 		/* EOF when recursively reading a header is bad. */
867 		archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
868 	return (ARCHIVE_FATAL);
869 }
870 
871 /*
872  * Return true if block checksum is correct.
873  */
874 static int
875 checksum(struct archive_read *a, const void *h)
876 {
877 	const unsigned char *bytes;
878 	const struct archive_entry_header_ustar	*header;
879 	int check, sum;
880 	size_t i;
881 
882 	(void)a; /* UNUSED */
883 	bytes = (const unsigned char *)h;
884 	header = (const struct archive_entry_header_ustar *)h;
885 
886 	/* Checksum field must hold an octal number */
887 	for (i = 0; i < sizeof(header->checksum); ++i) {
888 		char c = header->checksum[i];
889 		if (c != ' ' && c != '\0' && (c < '0' || c > '7'))
890 			return 0;
891 	}
892 
893 	/*
894 	 * Test the checksum.  Note that POSIX specifies _unsigned_
895 	 * bytes for this calculation.
896 	 */
897 	sum = (int)tar_atol(header->checksum, sizeof(header->checksum));
898 	check = 0;
899 	for (i = 0; i < 148; i++)
900 		check += (unsigned char)bytes[i];
901 	for (; i < 156; i++)
902 		check += 32;
903 	for (; i < 512; i++)
904 		check += (unsigned char)bytes[i];
905 	if (sum == check)
906 		return (1);
907 
908 	/*
909 	 * Repeat test with _signed_ bytes, just in case this archive
910 	 * was created by an old BSD, Solaris, or HP-UX tar with a
911 	 * broken checksum calculation.
912 	 */
913 	check = 0;
914 	for (i = 0; i < 148; i++)
915 		check += (signed char)bytes[i];
916 	for (; i < 156; i++)
917 		check += 32;
918 	for (; i < 512; i++)
919 		check += (signed char)bytes[i];
920 	if (sum == check)
921 		return (1);
922 
923 	return (0);
924 }
925 
926 /*
927  * Return true if this block contains only nulls.
928  */
929 static int
930 archive_block_is_null(const char *p)
931 {
932 	unsigned i;
933 
934 	for (i = 0; i < 512; i++)
935 		if (*p++)
936 			return (0);
937 	return (1);
938 }
939 
940 /*
941  * Interpret 'A' Solaris ACL header
942  */
943 static int
944 header_Solaris_ACL(struct archive_read *a, struct tar *tar,
945     struct archive_entry *entry, const void *h, size_t *unconsumed)
946 {
947 	const struct archive_entry_header_ustar *header;
948 	size_t size;
949 	int err, acl_type;
950 	int64_t type;
951 	char *acl, *p;
952 
953 	/*
954 	 * read_body_to_string adds a NUL terminator, but we need a little
955 	 * more to make sure that we don't overrun acl_text later.
956 	 */
957 	header = (const struct archive_entry_header_ustar *)h;
958 	size = (size_t)tar_atol(header->size, sizeof(header->size));
959 	err = read_body_to_string(a, tar, &(tar->acl_text), h, unconsumed);
960 	if (err != ARCHIVE_OK)
961 		return (err);
962 
963 	/* Recursively read next header */
964 	err = tar_read_header(a, tar, entry, unconsumed);
965 	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
966 		return (err);
967 
968 	/* TODO: Examine the first characters to see if this
969 	 * is an AIX ACL descriptor.  We'll likely never support
970 	 * them, but it would be polite to recognize and warn when
971 	 * we do see them. */
972 
973 	/* Leading octal number indicates ACL type and number of entries. */
974 	p = acl = tar->acl_text.s;
975 	type = 0;
976 	while (*p != '\0' && p < acl + size) {
977 		if (*p < '0' || *p > '7') {
978 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
979 			    "Malformed Solaris ACL attribute (invalid digit)");
980 			return(ARCHIVE_WARN);
981 		}
982 		type <<= 3;
983 		type += *p - '0';
984 		if (type > 077777777) {
985 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
986 			    "Malformed Solaris ACL attribute (count too large)");
987 			return (ARCHIVE_WARN);
988 		}
989 		p++;
990 	}
991 	switch ((int)type & ~0777777) {
992 	case 01000000:
993 		/* POSIX.1e ACL */
994 		acl_type = ARCHIVE_ENTRY_ACL_TYPE_ACCESS;
995 		break;
996 	case 03000000:
997 		/* NFSv4 ACL */
998 		acl_type = ARCHIVE_ENTRY_ACL_TYPE_NFS4;
999 		break;
1000 	default:
1001 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1002 		    "Malformed Solaris ACL attribute (unsupported type %o)",
1003 		    (int)type);
1004 		return (ARCHIVE_WARN);
1005 	}
1006 	p++;
1007 
1008 	if (p >= acl + size) {
1009 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1010 		    "Malformed Solaris ACL attribute (body overflow)");
1011 		return(ARCHIVE_WARN);
1012 	}
1013 
1014 	/* ACL text is null-terminated; find the end. */
1015 	size -= (p - acl);
1016 	acl = p;
1017 
1018 	while (*p != '\0' && p < acl + size)
1019 		p++;
1020 
1021 	if (tar->sconv_acl == NULL) {
1022 		tar->sconv_acl = archive_string_conversion_from_charset(
1023 		    &(a->archive), "UTF-8", 1);
1024 		if (tar->sconv_acl == NULL)
1025 			return (ARCHIVE_FATAL);
1026 	}
1027 	archive_strncpy(&(tar->localname), acl, p - acl);
1028 	err = archive_acl_from_text_l(archive_entry_acl(entry),
1029 	    tar->localname.s, acl_type, tar->sconv_acl);
1030 	if (err != ARCHIVE_OK) {
1031 		if (errno == ENOMEM) {
1032 			archive_set_error(&a->archive, ENOMEM,
1033 			    "Can't allocate memory for ACL");
1034 		} else
1035 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1036 			    "Malformed Solaris ACL attribute (unparsable)");
1037 	}
1038 	return (err);
1039 }
1040 
1041 /*
1042  * Interpret 'K' long linkname header.
1043  */
1044 static int
1045 header_longlink(struct archive_read *a, struct tar *tar,
1046     struct archive_entry *entry, const void *h, size_t *unconsumed)
1047 {
1048 	int err;
1049 
1050 	err = read_body_to_string(a, tar, &(tar->longlink), h, unconsumed);
1051 	if (err != ARCHIVE_OK)
1052 		return (err);
1053 	err = tar_read_header(a, tar, entry, unconsumed);
1054 	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1055 		return (err);
1056 	/* Set symlink if symlink already set, else hardlink. */
1057 	archive_entry_copy_link(entry, tar->longlink.s);
1058 	return (ARCHIVE_OK);
1059 }
1060 
1061 static int
1062 set_conversion_failed_error(struct archive_read *a,
1063     struct archive_string_conv *sconv, const char *name)
1064 {
1065 	if (errno == ENOMEM) {
1066 		archive_set_error(&a->archive, ENOMEM,
1067 		    "Can't allocate memory for %s", name);
1068 		return (ARCHIVE_FATAL);
1069 	}
1070 	archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
1071 	    "%s can't be converted from %s to current locale.",
1072 	    name, archive_string_conversion_charset_name(sconv));
1073 	return (ARCHIVE_WARN);
1074 }
1075 
1076 /*
1077  * Interpret 'L' long filename header.
1078  */
1079 static int
1080 header_longname(struct archive_read *a, struct tar *tar,
1081     struct archive_entry *entry, const void *h, size_t *unconsumed)
1082 {
1083 	int err;
1084 
1085 	err = read_body_to_string(a, tar, &(tar->longname), h, unconsumed);
1086 	if (err != ARCHIVE_OK)
1087 		return (err);
1088 	/* Read and parse "real" header, then override name. */
1089 	err = tar_read_header(a, tar, entry, unconsumed);
1090 	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1091 		return (err);
1092 	if (archive_entry_copy_pathname_l(entry, tar->longname.s,
1093 	    archive_strlen(&(tar->longname)), tar->sconv) != 0)
1094 		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1095 	return (err);
1096 }
1097 
1098 
1099 /*
1100  * Interpret 'V' GNU tar volume header.
1101  */
1102 static int
1103 header_volume(struct archive_read *a, struct tar *tar,
1104     struct archive_entry *entry, const void *h, size_t *unconsumed)
1105 {
1106 	(void)h;
1107 
1108 	/* Just skip this and read the next header. */
1109 	return (tar_read_header(a, tar, entry, unconsumed));
1110 }
1111 
1112 /*
1113  * Read body of an archive entry into an archive_string object.
1114  */
1115 static int
1116 read_body_to_string(struct archive_read *a, struct tar *tar,
1117     struct archive_string *as, const void *h, size_t *unconsumed)
1118 {
1119 	int64_t size;
1120 	const struct archive_entry_header_ustar *header;
1121 	const void *src;
1122 
1123 	(void)tar; /* UNUSED */
1124 	header = (const struct archive_entry_header_ustar *)h;
1125 	size  = tar_atol(header->size, sizeof(header->size));
1126 	if ((size > 1048576) || (size < 0)) {
1127 		archive_set_error(&a->archive, EINVAL,
1128 		    "Special header too large");
1129 		return (ARCHIVE_FATAL);
1130 	}
1131 
1132 	/* Fail if we can't make our buffer big enough. */
1133 	if (archive_string_ensure(as, (size_t)size+1) == NULL) {
1134 		archive_set_error(&a->archive, ENOMEM,
1135 		    "No memory");
1136 		return (ARCHIVE_FATAL);
1137 	}
1138 
1139 	tar_flush_unconsumed(a, unconsumed);
1140 
1141 	/* Read the body into the string. */
1142 	*unconsumed = (size_t)((size + 511) & ~ 511);
1143 	src = __archive_read_ahead(a, *unconsumed, NULL);
1144 	if (src == NULL) {
1145 		*unconsumed = 0;
1146 		return (ARCHIVE_FATAL);
1147 	}
1148 	memcpy(as->s, src, (size_t)size);
1149 	as->s[size] = '\0';
1150 	as->length = (size_t)size;
1151 	return (ARCHIVE_OK);
1152 }
1153 
1154 /*
1155  * Parse out common header elements.
1156  *
1157  * This would be the same as header_old_tar, except that the
1158  * filename is handled slightly differently for old and POSIX
1159  * entries  (POSIX entries support a 'prefix').  This factoring
1160  * allows header_old_tar and header_ustar
1161  * to handle filenames differently, while still putting most of the
1162  * common parsing into one place.
1163  */
1164 static int
1165 header_common(struct archive_read *a, struct tar *tar,
1166     struct archive_entry *entry, const void *h)
1167 {
1168 	const struct archive_entry_header_ustar	*header;
1169 	char	tartype;
1170 	int     err = ARCHIVE_OK;
1171 
1172 	header = (const struct archive_entry_header_ustar *)h;
1173 	if (header->linkname[0])
1174 		archive_strncpy(&(tar->entry_linkpath),
1175 		    header->linkname, sizeof(header->linkname));
1176 	else
1177 		archive_string_empty(&(tar->entry_linkpath));
1178 
1179 	/* Parse out the numeric fields (all are octal) */
1180 	archive_entry_set_mode(entry,
1181 		(mode_t)tar_atol(header->mode, sizeof(header->mode)));
1182 	archive_entry_set_uid(entry, tar_atol(header->uid, sizeof(header->uid)));
1183 	archive_entry_set_gid(entry, tar_atol(header->gid, sizeof(header->gid)));
1184 	tar->entry_bytes_remaining = tar_atol(header->size, sizeof(header->size));
1185 	if (tar->entry_bytes_remaining < 0) {
1186 		tar->entry_bytes_remaining = 0;
1187 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1188 		    "Tar entry has negative size");
1189 		return (ARCHIVE_FATAL);
1190 	}
1191 	if (tar->entry_bytes_remaining == INT64_MAX) {
1192 		/* Note: tar_atol returns INT64_MAX on overflow */
1193 		tar->entry_bytes_remaining = 0;
1194 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1195 		    "Tar entry size overflow");
1196 		return (ARCHIVE_FATAL);
1197 	}
1198 	tar->realsize = tar->entry_bytes_remaining;
1199 	archive_entry_set_size(entry, tar->entry_bytes_remaining);
1200 	archive_entry_set_mtime(entry, tar_atol(header->mtime, sizeof(header->mtime)), 0);
1201 
1202 	/* Handle the tar type flag appropriately. */
1203 	tartype = header->typeflag[0];
1204 
1205 	switch (tartype) {
1206 	case '1': /* Hard link */
1207 		if (archive_entry_copy_hardlink_l(entry, tar->entry_linkpath.s,
1208 		    archive_strlen(&(tar->entry_linkpath)), tar->sconv) != 0) {
1209 			err = set_conversion_failed_error(a, tar->sconv,
1210 			    "Linkname");
1211 			if (err == ARCHIVE_FATAL)
1212 				return (err);
1213 		}
1214 		/*
1215 		 * The following may seem odd, but: Technically, tar
1216 		 * does not store the file type for a "hard link"
1217 		 * entry, only the fact that it is a hard link.  So, I
1218 		 * leave the type zero normally.  But, pax interchange
1219 		 * format allows hard links to have data, which
1220 		 * implies that the underlying entry is a regular
1221 		 * file.
1222 		 */
1223 		if (archive_entry_size(entry) > 0)
1224 			archive_entry_set_filetype(entry, AE_IFREG);
1225 
1226 		/*
1227 		 * A tricky point: Traditionally, tar readers have
1228 		 * ignored the size field when reading hardlink
1229 		 * entries, and some writers put non-zero sizes even
1230 		 * though the body is empty.  POSIX blessed this
1231 		 * convention in the 1988 standard, but broke with
1232 		 * this tradition in 2001 by permitting hardlink
1233 		 * entries to store valid bodies in pax interchange
1234 		 * format, but not in ustar format.  Since there is no
1235 		 * hard and fast way to distinguish pax interchange
1236 		 * from earlier archives (the 'x' and 'g' entries are
1237 		 * optional, after all), we need a heuristic.
1238 		 */
1239 		if (archive_entry_size(entry) == 0) {
1240 			/* If the size is already zero, we're done. */
1241 		}  else if (a->archive.archive_format
1242 		    == ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
1243 			/* Definitely pax extended; must obey hardlink size. */
1244 		} else if (a->archive.archive_format == ARCHIVE_FORMAT_TAR
1245 		    || a->archive.archive_format == ARCHIVE_FORMAT_TAR_GNUTAR)
1246 		{
1247 			/* Old-style or GNU tar: we must ignore the size. */
1248 			archive_entry_set_size(entry, 0);
1249 			tar->entry_bytes_remaining = 0;
1250 		} else if (archive_read_format_tar_bid(a, 50) > 50) {
1251 			/*
1252 			 * We don't know if it's pax: If the bid
1253 			 * function sees a valid ustar header
1254 			 * immediately following, then let's ignore
1255 			 * the hardlink size.
1256 			 */
1257 			archive_entry_set_size(entry, 0);
1258 			tar->entry_bytes_remaining = 0;
1259 		}
1260 		/*
1261 		 * TODO: There are still two cases I'd like to handle:
1262 		 *   = a ustar non-pax archive with a hardlink entry at
1263 		 *     end-of-archive.  (Look for block of nulls following?)
1264 		 *   = a pax archive that has not seen any pax headers
1265 		 *     and has an entry which is a hardlink entry storing
1266 		 *     a body containing an uncompressed tar archive.
1267 		 * The first is worth addressing; I don't see any reliable
1268 		 * way to deal with the second possibility.
1269 		 */
1270 		break;
1271 	case '2': /* Symlink */
1272 		archive_entry_set_filetype(entry, AE_IFLNK);
1273 		archive_entry_set_size(entry, 0);
1274 		tar->entry_bytes_remaining = 0;
1275 		if (archive_entry_copy_symlink_l(entry, tar->entry_linkpath.s,
1276 		    archive_strlen(&(tar->entry_linkpath)), tar->sconv) != 0) {
1277 			err = set_conversion_failed_error(a, tar->sconv,
1278 			    "Linkname");
1279 			if (err == ARCHIVE_FATAL)
1280 				return (err);
1281 		}
1282 		break;
1283 	case '3': /* Character device */
1284 		archive_entry_set_filetype(entry, AE_IFCHR);
1285 		archive_entry_set_size(entry, 0);
1286 		tar->entry_bytes_remaining = 0;
1287 		break;
1288 	case '4': /* Block device */
1289 		archive_entry_set_filetype(entry, AE_IFBLK);
1290 		archive_entry_set_size(entry, 0);
1291 		tar->entry_bytes_remaining = 0;
1292 		break;
1293 	case '5': /* Dir */
1294 		archive_entry_set_filetype(entry, AE_IFDIR);
1295 		archive_entry_set_size(entry, 0);
1296 		tar->entry_bytes_remaining = 0;
1297 		break;
1298 	case '6': /* FIFO device */
1299 		archive_entry_set_filetype(entry, AE_IFIFO);
1300 		archive_entry_set_size(entry, 0);
1301 		tar->entry_bytes_remaining = 0;
1302 		break;
1303 	case 'D': /* GNU incremental directory type */
1304 		/*
1305 		 * No special handling is actually required here.
1306 		 * It might be nice someday to preprocess the file list and
1307 		 * provide it to the client, though.
1308 		 */
1309 		archive_entry_set_filetype(entry, AE_IFDIR);
1310 		break;
1311 	case 'M': /* GNU "Multi-volume" (remainder of file from last archive)*/
1312 		/*
1313 		 * As far as I can tell, this is just like a regular file
1314 		 * entry, except that the contents should be _appended_ to
1315 		 * the indicated file at the indicated offset.  This may
1316 		 * require some API work to fully support.
1317 		 */
1318 		break;
1319 	case 'N': /* Old GNU "long filename" entry. */
1320 		/* The body of this entry is a script for renaming
1321 		 * previously-extracted entries.  Ugh.  It will never
1322 		 * be supported by libarchive. */
1323 		archive_entry_set_filetype(entry, AE_IFREG);
1324 		break;
1325 	case 'S': /* GNU sparse files */
1326 		/*
1327 		 * Sparse files are really just regular files with
1328 		 * sparse information in the extended area.
1329 		 */
1330 		/* FALLTHROUGH */
1331 	case '0':
1332 		/*
1333 		 * Enable sparse file "read" support only for regular
1334 		 * files and explicit GNU sparse files.  However, we
1335 		 * don't allow non-standard file types to be sparse.
1336 		 */
1337 		tar->sparse_allowed = 1;
1338 		/* FALLTHROUGH */
1339 	default: /* Regular file  and non-standard types */
1340 		/*
1341 		 * Per POSIX: non-recognized types should always be
1342 		 * treated as regular files.
1343 		 */
1344 		archive_entry_set_filetype(entry, AE_IFREG);
1345 		break;
1346 	}
1347 	return (err);
1348 }
1349 
1350 /*
1351  * Parse out header elements for "old-style" tar archives.
1352  */
1353 static int
1354 header_old_tar(struct archive_read *a, struct tar *tar,
1355     struct archive_entry *entry, const void *h)
1356 {
1357 	const struct archive_entry_header_ustar	*header;
1358 	int err = ARCHIVE_OK, err2;
1359 
1360 	/* Copy filename over (to ensure null termination). */
1361 	header = (const struct archive_entry_header_ustar *)h;
1362 	if (archive_entry_copy_pathname_l(entry,
1363 	    header->name, sizeof(header->name), tar->sconv) != 0) {
1364 		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1365 		if (err == ARCHIVE_FATAL)
1366 			return (err);
1367 	}
1368 
1369 	/* Grab rest of common fields */
1370 	err2 = header_common(a, tar, entry, h);
1371 	if (err > err2)
1372 		err = err2;
1373 
1374 	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1375 	return (err);
1376 }
1377 
1378 /*
1379  * Read a Mac AppleDouble-encoded blob of file metadata,
1380  * if there is one.
1381  */
1382 static int
1383 read_mac_metadata_blob(struct archive_read *a, struct tar *tar,
1384     struct archive_entry *entry, const void *h, size_t *unconsumed)
1385 {
1386 	int64_t size;
1387 	const void *data;
1388 	const char *p, *name;
1389 	const wchar_t *wp, *wname;
1390 
1391 	(void)h; /* UNUSED */
1392 
1393 	wname = wp = archive_entry_pathname_w(entry);
1394 	if (wp != NULL) {
1395 		/* Find the last path element. */
1396 		for (; *wp != L'\0'; ++wp) {
1397 			if (wp[0] == '/' && wp[1] != L'\0')
1398 				wname = wp + 1;
1399 		}
1400 		/*
1401 		 * If last path element starts with "._", then
1402 		 * this is a Mac extension.
1403 		 */
1404 		if (wname[0] != L'.' || wname[1] != L'_' || wname[2] == L'\0')
1405 			return ARCHIVE_OK;
1406 	} else {
1407 		/* Find the last path element. */
1408 		name = p = archive_entry_pathname(entry);
1409 		if (p == NULL)
1410 			return (ARCHIVE_FAILED);
1411 		for (; *p != '\0'; ++p) {
1412 			if (p[0] == '/' && p[1] != '\0')
1413 				name = p + 1;
1414 		}
1415 		/*
1416 		 * If last path element starts with "._", then
1417 		 * this is a Mac extension.
1418 		 */
1419 		if (name[0] != '.' || name[1] != '_' || name[2] == '\0')
1420 			return ARCHIVE_OK;
1421 	}
1422 
1423  	/* Read the body as a Mac OS metadata blob. */
1424 	size = archive_entry_size(entry);
1425 
1426 	/*
1427 	 * TODO: Look beyond the body here to peek at the next header.
1428 	 * If it's a regular header (not an extension header)
1429 	 * that has the wrong name, just return the current
1430 	 * entry as-is, without consuming the body here.
1431 	 * That would reduce the risk of us mis-identifying
1432 	 * an ordinary file that just happened to have
1433 	 * a name starting with "._".
1434 	 *
1435 	 * Q: Is the above idea really possible?  Even
1436 	 * when there are GNU or pax extension entries?
1437 	 */
1438 	data = __archive_read_ahead(a, (size_t)size, NULL);
1439 	if (data == NULL) {
1440 		*unconsumed = 0;
1441 		return (ARCHIVE_FATAL);
1442 	}
1443 	archive_entry_copy_mac_metadata(entry, data, (size_t)size);
1444 	*unconsumed = (size_t)((size + 511) & ~ 511);
1445 	tar_flush_unconsumed(a, unconsumed);
1446 	return (tar_read_header(a, tar, entry, unconsumed));
1447 }
1448 
1449 /*
1450  * Parse a file header for a pax extended archive entry.
1451  */
1452 static int
1453 header_pax_global(struct archive_read *a, struct tar *tar,
1454     struct archive_entry *entry, const void *h, size_t *unconsumed)
1455 {
1456 	int err;
1457 
1458 	err = read_body_to_string(a, tar, &(tar->pax_global), h, unconsumed);
1459 	if (err != ARCHIVE_OK)
1460 		return (err);
1461 	err = tar_read_header(a, tar, entry, unconsumed);
1462 	return (err);
1463 }
1464 
1465 static int
1466 header_pax_extensions(struct archive_read *a, struct tar *tar,
1467     struct archive_entry *entry, const void *h, size_t *unconsumed)
1468 {
1469 	int err, err2;
1470 
1471 	err = read_body_to_string(a, tar, &(tar->pax_header), h, unconsumed);
1472 	if (err != ARCHIVE_OK)
1473 		return (err);
1474 
1475 	/* Parse the next header. */
1476 	err = tar_read_header(a, tar, entry, unconsumed);
1477 	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1478 		return (err);
1479 
1480 	/*
1481 	 * TODO: Parse global/default options into 'entry' struct here
1482 	 * before handling file-specific options.
1483 	 *
1484 	 * This design (parse standard header, then overwrite with pax
1485 	 * extended attribute data) usually works well, but isn't ideal;
1486 	 * it would be better to parse the pax extended attributes first
1487 	 * and then skip any fields in the standard header that were
1488 	 * defined in the pax header.
1489 	 */
1490 	err2 = pax_header(a, tar, entry, &tar->pax_header);
1491 	err =  err_combine(err, err2);
1492 	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1493 	return (err);
1494 }
1495 
1496 
1497 /*
1498  * Parse a file header for a Posix "ustar" archive entry.  This also
1499  * handles "pax" or "extended ustar" entries.
1500  */
1501 static int
1502 header_ustar(struct archive_read *a, struct tar *tar,
1503     struct archive_entry *entry, const void *h)
1504 {
1505 	const struct archive_entry_header_ustar	*header;
1506 	struct archive_string *as;
1507 	int err = ARCHIVE_OK, r;
1508 
1509 	header = (const struct archive_entry_header_ustar *)h;
1510 
1511 	/* Copy name into an internal buffer to ensure null-termination. */
1512 	as = &(tar->entry_pathname);
1513 	if (header->prefix[0]) {
1514 		archive_strncpy(as, header->prefix, sizeof(header->prefix));
1515 		if (as->s[archive_strlen(as) - 1] != '/')
1516 			archive_strappend_char(as, '/');
1517 		archive_strncat(as, header->name, sizeof(header->name));
1518 	} else {
1519 		archive_strncpy(as, header->name, sizeof(header->name));
1520 	}
1521 	if (archive_entry_copy_pathname_l(entry, as->s, archive_strlen(as),
1522 	    tar->sconv) != 0) {
1523 		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1524 		if (err == ARCHIVE_FATAL)
1525 			return (err);
1526 	}
1527 
1528 	/* Handle rest of common fields. */
1529 	r = header_common(a, tar, entry, h);
1530 	if (r == ARCHIVE_FATAL)
1531 		return (r);
1532 	if (r < err)
1533 		err = r;
1534 
1535 	/* Handle POSIX ustar fields. */
1536 	if (archive_entry_copy_uname_l(entry,
1537 	    header->uname, sizeof(header->uname), tar->sconv) != 0) {
1538 		err = set_conversion_failed_error(a, tar->sconv, "Uname");
1539 		if (err == ARCHIVE_FATAL)
1540 			return (err);
1541 	}
1542 
1543 	if (archive_entry_copy_gname_l(entry,
1544 	    header->gname, sizeof(header->gname), tar->sconv) != 0) {
1545 		err = set_conversion_failed_error(a, tar->sconv, "Gname");
1546 		if (err == ARCHIVE_FATAL)
1547 			return (err);
1548 	}
1549 
1550 	/* Parse out device numbers only for char and block specials. */
1551 	if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
1552 		archive_entry_set_rdevmajor(entry, (dev_t)
1553 		    tar_atol(header->rdevmajor, sizeof(header->rdevmajor)));
1554 		archive_entry_set_rdevminor(entry, (dev_t)
1555 		    tar_atol(header->rdevminor, sizeof(header->rdevminor)));
1556 	}
1557 
1558 	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1559 
1560 	return (err);
1561 }
1562 
1563 
1564 /*
1565  * Parse the pax extended attributes record.
1566  *
1567  * Returns non-zero if there's an error in the data.
1568  */
1569 static int
1570 pax_header(struct archive_read *a, struct tar *tar,
1571     struct archive_entry *entry, struct archive_string *in_as)
1572 {
1573 	size_t attr_length, l, line_length, value_length;
1574 	char *p;
1575 	char *key, *value;
1576 	struct archive_string *as;
1577 	struct archive_string_conv *sconv;
1578 	int err, err2;
1579 	char *attr = in_as->s;
1580 
1581 	attr_length = in_as->length;
1582 	tar->pax_hdrcharset_binary = 0;
1583 	archive_string_empty(&(tar->entry_gname));
1584 	archive_string_empty(&(tar->entry_linkpath));
1585 	archive_string_empty(&(tar->entry_pathname));
1586 	archive_string_empty(&(tar->entry_pathname_override));
1587 	archive_string_empty(&(tar->entry_uname));
1588 	err = ARCHIVE_OK;
1589 	while (attr_length > 0) {
1590 		/* Parse decimal length field at start of line. */
1591 		line_length = 0;
1592 		l = attr_length;
1593 		p = attr; /* Record start of line. */
1594 		while (l>0) {
1595 			if (*p == ' ') {
1596 				p++;
1597 				l--;
1598 				break;
1599 			}
1600 			if (*p < '0' || *p > '9') {
1601 				archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1602 				    "Ignoring malformed pax extended attributes");
1603 				return (ARCHIVE_WARN);
1604 			}
1605 			line_length *= 10;
1606 			line_length += *p - '0';
1607 			if (line_length > 999999) {
1608 				archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1609 				    "Rejecting pax extended attribute > 1MB");
1610 				return (ARCHIVE_WARN);
1611 			}
1612 			p++;
1613 			l--;
1614 		}
1615 
1616 		/*
1617 		 * Parsed length must be no bigger than available data,
1618 		 * at least 1, and the last character of the line must
1619 		 * be '\n'.
1620 		 */
1621 		if (line_length > attr_length
1622 		    || line_length < 1
1623 		    || attr[line_length - 1] != '\n')
1624 		{
1625 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1626 			    "Ignoring malformed pax extended attribute");
1627 			return (ARCHIVE_WARN);
1628 		}
1629 
1630 		/* Null-terminate the line. */
1631 		attr[line_length - 1] = '\0';
1632 
1633 		/* Find end of key and null terminate it. */
1634 		key = p;
1635 		if (key[0] == '=')
1636 			return (-1);
1637 		while (*p && *p != '=')
1638 			++p;
1639 		if (*p == '\0') {
1640 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1641 			    "Invalid pax extended attributes");
1642 			return (ARCHIVE_WARN);
1643 		}
1644 		*p = '\0';
1645 
1646 		value = p + 1;
1647 
1648 		/* Some values may be binary data */
1649 		value_length = attr + line_length - 1 - value;
1650 
1651 		/* Identify this attribute and set it in the entry. */
1652 		err2 = pax_attribute(a, tar, entry, key, value, value_length);
1653 		if (err2 == ARCHIVE_FATAL)
1654 			return (err2);
1655 		err = err_combine(err, err2);
1656 
1657 		/* Skip to next line */
1658 		attr += line_length;
1659 		attr_length -= line_length;
1660 	}
1661 
1662 	/*
1663 	 * PAX format uses UTF-8 as default charset for its metadata
1664 	 * unless hdrcharset=BINARY is present in its header.
1665 	 * We apply the charset specified by the hdrcharset option only
1666 	 * when the hdrcharset attribute(in PAX header) is BINARY because
1667 	 * we respect the charset described in PAX header and BINARY also
1668 	 * means that metadata(filename,uname and gname) character-set
1669 	 * is unknown.
1670 	 */
1671 	if (tar->pax_hdrcharset_binary)
1672 		sconv = tar->opt_sconv;
1673 	else {
1674 		sconv = archive_string_conversion_from_charset(
1675 		    &(a->archive), "UTF-8", 1);
1676 		if (sconv == NULL)
1677 			return (ARCHIVE_FATAL);
1678 		if (tar->compat_2x)
1679 			archive_string_conversion_set_opt(sconv,
1680 			    SCONV_SET_OPT_UTF8_LIBARCHIVE2X);
1681 	}
1682 
1683 	if (archive_strlen(&(tar->entry_gname)) > 0) {
1684 		if (archive_entry_copy_gname_l(entry, tar->entry_gname.s,
1685 		    archive_strlen(&(tar->entry_gname)), sconv) != 0) {
1686 			err = set_conversion_failed_error(a, sconv, "Gname");
1687 			if (err == ARCHIVE_FATAL)
1688 				return (err);
1689 			/* Use a converted an original name. */
1690 			archive_entry_copy_gname(entry, tar->entry_gname.s);
1691 		}
1692 	}
1693 	if (archive_strlen(&(tar->entry_linkpath)) > 0) {
1694 		if (archive_entry_copy_link_l(entry, tar->entry_linkpath.s,
1695 		    archive_strlen(&(tar->entry_linkpath)), sconv) != 0) {
1696 			err = set_conversion_failed_error(a, sconv, "Linkname");
1697 			if (err == ARCHIVE_FATAL)
1698 				return (err);
1699 			/* Use a converted an original name. */
1700 			archive_entry_copy_link(entry, tar->entry_linkpath.s);
1701 		}
1702 	}
1703 	/*
1704 	 * Some extensions (such as the GNU sparse file extensions)
1705 	 * deliberately store a synthetic name under the regular 'path'
1706 	 * attribute and the real file name under a different attribute.
1707 	 * Since we're supposed to not care about the order, we
1708 	 * have no choice but to store all of the various filenames
1709 	 * we find and figure it all out afterwards.  This is the
1710 	 * figuring out part.
1711 	 */
1712 	as = NULL;
1713 	if (archive_strlen(&(tar->entry_pathname_override)) > 0)
1714 		as = &(tar->entry_pathname_override);
1715 	else if (archive_strlen(&(tar->entry_pathname)) > 0)
1716 		as = &(tar->entry_pathname);
1717 	if (as != NULL) {
1718 		if (archive_entry_copy_pathname_l(entry, as->s,
1719 		    archive_strlen(as), sconv) != 0) {
1720 			err = set_conversion_failed_error(a, sconv, "Pathname");
1721 			if (err == ARCHIVE_FATAL)
1722 				return (err);
1723 			/* Use a converted an original name. */
1724 			archive_entry_copy_pathname(entry, as->s);
1725 		}
1726 	}
1727 	if (archive_strlen(&(tar->entry_uname)) > 0) {
1728 		if (archive_entry_copy_uname_l(entry, tar->entry_uname.s,
1729 		    archive_strlen(&(tar->entry_uname)), sconv) != 0) {
1730 			err = set_conversion_failed_error(a, sconv, "Uname");
1731 			if (err == ARCHIVE_FATAL)
1732 				return (err);
1733 			/* Use a converted an original name. */
1734 			archive_entry_copy_uname(entry, tar->entry_uname.s);
1735 		}
1736 	}
1737 	return (err);
1738 }
1739 
1740 static int
1741 pax_attribute_xattr(struct archive_entry *entry,
1742 	const char *name, const char *value)
1743 {
1744 	char *name_decoded;
1745 	void *value_decoded;
1746 	size_t value_len;
1747 
1748 	if (strlen(name) < 18 || (memcmp(name, "LIBARCHIVE.xattr.", 17)) != 0)
1749 		return 3;
1750 
1751 	name += 17;
1752 
1753 	/* URL-decode name */
1754 	name_decoded = url_decode(name);
1755 	if (name_decoded == NULL)
1756 		return 2;
1757 
1758 	/* Base-64 decode value */
1759 	value_decoded = base64_decode(value, strlen(value), &value_len);
1760 	if (value_decoded == NULL) {
1761 		free(name_decoded);
1762 		return 1;
1763 	}
1764 
1765 	archive_entry_xattr_add_entry(entry, name_decoded,
1766 		value_decoded, value_len);
1767 
1768 	free(name_decoded);
1769 	free(value_decoded);
1770 	return 0;
1771 }
1772 
1773 static int
1774 pax_attribute_schily_xattr(struct archive_entry *entry,
1775 	const char *name, const char *value, size_t value_length)
1776 {
1777 	if (strlen(name) < 14 || (memcmp(name, "SCHILY.xattr.", 13)) != 0)
1778 		return 1;
1779 
1780 	name += 13;
1781 
1782 	archive_entry_xattr_add_entry(entry, name, value, value_length);
1783 
1784 	return 0;
1785 }
1786 
1787 static int
1788 pax_attribute_acl(struct archive_read *a, struct tar *tar,
1789     struct archive_entry *entry, const char *value, int type)
1790 {
1791 	int r;
1792 	const char* errstr;
1793 
1794 	switch (type) {
1795 	case ARCHIVE_ENTRY_ACL_TYPE_ACCESS:
1796 		errstr = "SCHILY.acl.access";
1797 		break;
1798 	case ARCHIVE_ENTRY_ACL_TYPE_DEFAULT:
1799 		errstr = "SCHILY.acl.default";
1800 		break;
1801 	case ARCHIVE_ENTRY_ACL_TYPE_NFS4:
1802 		errstr = "SCHILY.acl.ace";
1803 		break;
1804 	default:
1805 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1806 		    "Unknown ACL type: %d", type);
1807 		return(ARCHIVE_FATAL);
1808 	}
1809 
1810 	if (tar->sconv_acl == NULL) {
1811 		tar->sconv_acl =
1812 		    archive_string_conversion_from_charset(
1813 			&(a->archive), "UTF-8", 1);
1814 		if (tar->sconv_acl == NULL)
1815 			return (ARCHIVE_FATAL);
1816 	}
1817 
1818 	r = archive_acl_from_text_l(archive_entry_acl(entry), value, type,
1819 	    tar->sconv_acl);
1820 	if (r != ARCHIVE_OK) {
1821 		if (r == ARCHIVE_FATAL) {
1822 			archive_set_error(&a->archive, ENOMEM,
1823 			    "%s %s", "Can't allocate memory for ",
1824 			    errstr);
1825 			return (r);
1826 		}
1827 		archive_set_error(&a->archive,
1828 		    ARCHIVE_ERRNO_MISC, "%s %s", "Parse error: ", errstr);
1829 	}
1830 	return (r);
1831 }
1832 
1833 /*
1834  * Parse a single key=value attribute.  key/value pointers are
1835  * assumed to point into reasonably long-lived storage.
1836  *
1837  * Note that POSIX reserves all-lowercase keywords.  Vendor-specific
1838  * extensions should always have keywords of the form "VENDOR.attribute"
1839  * In particular, it's quite feasible to support many different
1840  * vendor extensions here.  I'm using "LIBARCHIVE" for extensions
1841  * unique to this library.
1842  *
1843  * Investigate other vendor-specific extensions and see if
1844  * any of them look useful.
1845  */
1846 static int
1847 pax_attribute(struct archive_read *a, struct tar *tar,
1848     struct archive_entry *entry, const char *key, const char *value, size_t value_length)
1849 {
1850 	int64_t s;
1851 	long n;
1852 	int err = ARCHIVE_OK, r;
1853 
1854 	if (value == NULL)
1855 		value = "";	/* Disable compiler warning; do not pass
1856 				 * NULL pointer to strlen().  */
1857 	switch (key[0]) {
1858 	case 'G':
1859 		/* Reject GNU.sparse.* headers on non-regular files. */
1860 		if (strncmp(key, "GNU.sparse", 10) == 0 &&
1861 		    !tar->sparse_allowed) {
1862 			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1863 			    "Non-regular file cannot be sparse");
1864 			return (ARCHIVE_FATAL);
1865 		}
1866 
1867 		/* GNU "0.0" sparse pax format. */
1868 		if (strcmp(key, "GNU.sparse.numblocks") == 0) {
1869 			tar->sparse_offset = -1;
1870 			tar->sparse_numbytes = -1;
1871 			tar->sparse_gnu_major = 0;
1872 			tar->sparse_gnu_minor = 0;
1873 		}
1874 		if (strcmp(key, "GNU.sparse.offset") == 0) {
1875 			tar->sparse_offset = tar_atol10(value, strlen(value));
1876 			if (tar->sparse_numbytes != -1) {
1877 				if (gnu_add_sparse_entry(a, tar,
1878 				    tar->sparse_offset, tar->sparse_numbytes)
1879 				    != ARCHIVE_OK)
1880 					return (ARCHIVE_FATAL);
1881 				tar->sparse_offset = -1;
1882 				tar->sparse_numbytes = -1;
1883 			}
1884 		}
1885 		if (strcmp(key, "GNU.sparse.numbytes") == 0) {
1886 			tar->sparse_numbytes = tar_atol10(value, strlen(value));
1887 			if (tar->sparse_numbytes != -1) {
1888 				if (gnu_add_sparse_entry(a, tar,
1889 				    tar->sparse_offset, tar->sparse_numbytes)
1890 				    != ARCHIVE_OK)
1891 					return (ARCHIVE_FATAL);
1892 				tar->sparse_offset = -1;
1893 				tar->sparse_numbytes = -1;
1894 			}
1895 		}
1896 		if (strcmp(key, "GNU.sparse.size") == 0) {
1897 			tar->realsize = tar_atol10(value, strlen(value));
1898 			archive_entry_set_size(entry, tar->realsize);
1899 			tar->realsize_override = 1;
1900 		}
1901 
1902 		/* GNU "0.1" sparse pax format. */
1903 		if (strcmp(key, "GNU.sparse.map") == 0) {
1904 			tar->sparse_gnu_major = 0;
1905 			tar->sparse_gnu_minor = 1;
1906 			if (gnu_sparse_01_parse(a, tar, value) != ARCHIVE_OK)
1907 				return (ARCHIVE_WARN);
1908 		}
1909 
1910 		/* GNU "1.0" sparse pax format */
1911 		if (strcmp(key, "GNU.sparse.major") == 0) {
1912 			tar->sparse_gnu_major = (int)tar_atol10(value, strlen(value));
1913 			tar->sparse_gnu_pending = 1;
1914 		}
1915 		if (strcmp(key, "GNU.sparse.minor") == 0) {
1916 			tar->sparse_gnu_minor = (int)tar_atol10(value, strlen(value));
1917 			tar->sparse_gnu_pending = 1;
1918 		}
1919 		if (strcmp(key, "GNU.sparse.name") == 0) {
1920 			/*
1921 			 * The real filename; when storing sparse
1922 			 * files, GNU tar puts a synthesized name into
1923 			 * the regular 'path' attribute in an attempt
1924 			 * to limit confusion. ;-)
1925 			 */
1926 			archive_strcpy(&(tar->entry_pathname_override), value);
1927 		}
1928 		if (strcmp(key, "GNU.sparse.realsize") == 0) {
1929 			tar->realsize = tar_atol10(value, strlen(value));
1930 			archive_entry_set_size(entry, tar->realsize);
1931 			tar->realsize_override = 1;
1932 		}
1933 		break;
1934 	case 'L':
1935 		/* Our extensions */
1936 /* TODO: Handle arbitrary extended attributes... */
1937 /*
1938 		if (strcmp(key, "LIBARCHIVE.xxxxxxx") == 0)
1939 			archive_entry_set_xxxxxx(entry, value);
1940 */
1941 		if (strcmp(key, "LIBARCHIVE.creationtime") == 0) {
1942 			pax_time(value, &s, &n);
1943 			archive_entry_set_birthtime(entry, s, n);
1944 		}
1945 		if (memcmp(key, "LIBARCHIVE.xattr.", 17) == 0)
1946 			pax_attribute_xattr(entry, key, value);
1947 		break;
1948 	case 'S':
1949 		/* We support some keys used by the "star" archiver */
1950 		if (strcmp(key, "SCHILY.acl.access") == 0) {
1951 			r = pax_attribute_acl(a, tar, entry, value,
1952 			    ARCHIVE_ENTRY_ACL_TYPE_ACCESS);
1953 			if (r == ARCHIVE_FATAL)
1954 				return (r);
1955 		} else if (strcmp(key, "SCHILY.acl.default") == 0) {
1956 			r = pax_attribute_acl(a, tar, entry, value,
1957 			    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT);
1958 			if (r == ARCHIVE_FATAL)
1959 				return (r);
1960 		} else if (strcmp(key, "SCHILY.acl.ace") == 0) {
1961 			r = pax_attribute_acl(a, tar, entry, value,
1962 			    ARCHIVE_ENTRY_ACL_TYPE_NFS4);
1963 			if (r == ARCHIVE_FATAL)
1964 				return (r);
1965 		} else if (strcmp(key, "SCHILY.devmajor") == 0) {
1966 			archive_entry_set_rdevmajor(entry,
1967 			    (dev_t)tar_atol10(value, strlen(value)));
1968 		} else if (strcmp(key, "SCHILY.devminor") == 0) {
1969 			archive_entry_set_rdevminor(entry,
1970 			    (dev_t)tar_atol10(value, strlen(value)));
1971 		} else if (strcmp(key, "SCHILY.fflags") == 0) {
1972 			archive_entry_copy_fflags_text(entry, value);
1973 		} else if (strcmp(key, "SCHILY.dev") == 0) {
1974 			archive_entry_set_dev(entry,
1975 			    (dev_t)tar_atol10(value, strlen(value)));
1976 		} else if (strcmp(key, "SCHILY.ino") == 0) {
1977 			archive_entry_set_ino(entry,
1978 			    tar_atol10(value, strlen(value)));
1979 		} else if (strcmp(key, "SCHILY.nlink") == 0) {
1980 			archive_entry_set_nlink(entry, (unsigned)
1981 			    tar_atol10(value, strlen(value)));
1982 		} else if (strcmp(key, "SCHILY.realsize") == 0) {
1983 			tar->realsize = tar_atol10(value, strlen(value));
1984 			tar->realsize_override = 1;
1985 			archive_entry_set_size(entry, tar->realsize);
1986 		} else if (strncmp(key, "SCHILY.xattr.", 13) == 0) {
1987 			pax_attribute_schily_xattr(entry, key, value,
1988 			    value_length);
1989 		} else if (strcmp(key, "SUN.holesdata") == 0) {
1990 			/* A Solaris extension for sparse. */
1991 			r = solaris_sparse_parse(a, tar, entry, value);
1992 			if (r < err) {
1993 				if (r == ARCHIVE_FATAL)
1994 					return (r);
1995 				err = r;
1996 				archive_set_error(&a->archive,
1997 				    ARCHIVE_ERRNO_MISC,
1998 				    "Parse error: SUN.holesdata");
1999 			}
2000 		}
2001 		break;
2002 	case 'a':
2003 		if (strcmp(key, "atime") == 0) {
2004 			pax_time(value, &s, &n);
2005 			archive_entry_set_atime(entry, s, n);
2006 		}
2007 		break;
2008 	case 'c':
2009 		if (strcmp(key, "ctime") == 0) {
2010 			pax_time(value, &s, &n);
2011 			archive_entry_set_ctime(entry, s, n);
2012 		} else if (strcmp(key, "charset") == 0) {
2013 			/* TODO: Publish charset information in entry. */
2014 		} else if (strcmp(key, "comment") == 0) {
2015 			/* TODO: Publish comment in entry. */
2016 		}
2017 		break;
2018 	case 'g':
2019 		if (strcmp(key, "gid") == 0) {
2020 			archive_entry_set_gid(entry,
2021 			    tar_atol10(value, strlen(value)));
2022 		} else if (strcmp(key, "gname") == 0) {
2023 			archive_strcpy(&(tar->entry_gname), value);
2024 		}
2025 		break;
2026 	case 'h':
2027 		if (strcmp(key, "hdrcharset") == 0) {
2028 			if (strcmp(value, "BINARY") == 0)
2029 				/* Binary  mode. */
2030 				tar->pax_hdrcharset_binary = 1;
2031 			else if (strcmp(value, "ISO-IR 10646 2000 UTF-8") == 0)
2032 				tar->pax_hdrcharset_binary = 0;
2033 		}
2034 		break;
2035 	case 'l':
2036 		/* pax interchange doesn't distinguish hardlink vs. symlink. */
2037 		if (strcmp(key, "linkpath") == 0) {
2038 			archive_strcpy(&(tar->entry_linkpath), value);
2039 		}
2040 		break;
2041 	case 'm':
2042 		if (strcmp(key, "mtime") == 0) {
2043 			pax_time(value, &s, &n);
2044 			archive_entry_set_mtime(entry, s, n);
2045 		}
2046 		break;
2047 	case 'p':
2048 		if (strcmp(key, "path") == 0) {
2049 			archive_strcpy(&(tar->entry_pathname), value);
2050 		}
2051 		break;
2052 	case 'r':
2053 		/* POSIX has reserved 'realtime.*' */
2054 		break;
2055 	case 's':
2056 		/* POSIX has reserved 'security.*' */
2057 		/* Someday: if (strcmp(key, "security.acl") == 0) { ... } */
2058 		if (strcmp(key, "size") == 0) {
2059 			/* "size" is the size of the data in the entry. */
2060 			tar->entry_bytes_remaining
2061 			    = tar_atol10(value, strlen(value));
2062 			/*
2063 			 * The "size" pax header keyword always overrides the
2064 			 * "size" field in the tar header.
2065 			 * GNU.sparse.realsize, GNU.sparse.size and
2066 			 * SCHILY.realsize override this value.
2067 			 */
2068 			if (!tar->realsize_override) {
2069 				archive_entry_set_size(entry,
2070 				    tar->entry_bytes_remaining);
2071 				tar->realsize
2072 				    = tar->entry_bytes_remaining;
2073 			}
2074 		}
2075 		break;
2076 	case 'u':
2077 		if (strcmp(key, "uid") == 0) {
2078 			archive_entry_set_uid(entry,
2079 			    tar_atol10(value, strlen(value)));
2080 		} else if (strcmp(key, "uname") == 0) {
2081 			archive_strcpy(&(tar->entry_uname), value);
2082 		}
2083 		break;
2084 	}
2085 	return (err);
2086 }
2087 
2088 
2089 
2090 /*
2091  * parse a decimal time value, which may include a fractional portion
2092  */
2093 static void
2094 pax_time(const char *p, int64_t *ps, long *pn)
2095 {
2096 	char digit;
2097 	int64_t	s;
2098 	unsigned long l;
2099 	int sign;
2100 	int64_t limit, last_digit_limit;
2101 
2102 	limit = INT64_MAX / 10;
2103 	last_digit_limit = INT64_MAX % 10;
2104 
2105 	s = 0;
2106 	sign = 1;
2107 	if (*p == '-') {
2108 		sign = -1;
2109 		p++;
2110 	}
2111 	while (*p >= '0' && *p <= '9') {
2112 		digit = *p - '0';
2113 		if (s > limit ||
2114 		    (s == limit && digit > last_digit_limit)) {
2115 			s = INT64_MAX;
2116 			break;
2117 		}
2118 		s = (s * 10) + digit;
2119 		++p;
2120 	}
2121 
2122 	*ps = s * sign;
2123 
2124 	/* Calculate nanoseconds. */
2125 	*pn = 0;
2126 
2127 	if (*p != '.')
2128 		return;
2129 
2130 	l = 100000000UL;
2131 	do {
2132 		++p;
2133 		if (*p >= '0' && *p <= '9')
2134 			*pn += (*p - '0') * l;
2135 		else
2136 			break;
2137 	} while (l /= 10);
2138 }
2139 
2140 /*
2141  * Parse GNU tar header
2142  */
2143 static int
2144 header_gnutar(struct archive_read *a, struct tar *tar,
2145     struct archive_entry *entry, const void *h, size_t *unconsumed)
2146 {
2147 	const struct archive_entry_header_gnutar *header;
2148 	int64_t t;
2149 	int err = ARCHIVE_OK;
2150 
2151 	/*
2152 	 * GNU header is like POSIX ustar, except 'prefix' is
2153 	 * replaced with some other fields. This also means the
2154 	 * filename is stored as in old-style archives.
2155 	 */
2156 
2157 	/* Grab fields common to all tar variants. */
2158 	err = header_common(a, tar, entry, h);
2159 	if (err == ARCHIVE_FATAL)
2160 		return (err);
2161 
2162 	/* Copy filename over (to ensure null termination). */
2163 	header = (const struct archive_entry_header_gnutar *)h;
2164 	if (archive_entry_copy_pathname_l(entry,
2165 	    header->name, sizeof(header->name), tar->sconv) != 0) {
2166 		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
2167 		if (err == ARCHIVE_FATAL)
2168 			return (err);
2169 	}
2170 
2171 	/* Fields common to ustar and GNU */
2172 	/* XXX Can the following be factored out since it's common
2173 	 * to ustar and gnu tar?  Is it okay to move it down into
2174 	 * header_common, perhaps?  */
2175 	if (archive_entry_copy_uname_l(entry,
2176 	    header->uname, sizeof(header->uname), tar->sconv) != 0) {
2177 		err = set_conversion_failed_error(a, tar->sconv, "Uname");
2178 		if (err == ARCHIVE_FATAL)
2179 			return (err);
2180 	}
2181 
2182 	if (archive_entry_copy_gname_l(entry,
2183 	    header->gname, sizeof(header->gname), tar->sconv) != 0) {
2184 		err = set_conversion_failed_error(a, tar->sconv, "Gname");
2185 		if (err == ARCHIVE_FATAL)
2186 			return (err);
2187 	}
2188 
2189 	/* Parse out device numbers only for char and block specials */
2190 	if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
2191 		archive_entry_set_rdevmajor(entry, (dev_t)
2192 		    tar_atol(header->rdevmajor, sizeof(header->rdevmajor)));
2193 		archive_entry_set_rdevminor(entry, (dev_t)
2194 		    tar_atol(header->rdevminor, sizeof(header->rdevminor)));
2195 	} else
2196 		archive_entry_set_rdev(entry, 0);
2197 
2198 	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
2199 
2200 	/* Grab GNU-specific fields. */
2201 	t = tar_atol(header->atime, sizeof(header->atime));
2202 	if (t > 0)
2203 		archive_entry_set_atime(entry, t, 0);
2204 	t = tar_atol(header->ctime, sizeof(header->ctime));
2205 	if (t > 0)
2206 		archive_entry_set_ctime(entry, t, 0);
2207 
2208 	if (header->realsize[0] != 0) {
2209 		tar->realsize
2210 		    = tar_atol(header->realsize, sizeof(header->realsize));
2211 		archive_entry_set_size(entry, tar->realsize);
2212 		tar->realsize_override = 1;
2213 	}
2214 
2215 	if (header->sparse[0].offset[0] != 0) {
2216 		if (gnu_sparse_old_read(a, tar, header, unconsumed)
2217 		    != ARCHIVE_OK)
2218 			return (ARCHIVE_FATAL);
2219 	} else {
2220 		if (header->isextended[0] != 0) {
2221 			/* XXX WTF? XXX */
2222 		}
2223 	}
2224 
2225 	return (err);
2226 }
2227 
2228 static int
2229 gnu_add_sparse_entry(struct archive_read *a, struct tar *tar,
2230     int64_t offset, int64_t remaining)
2231 {
2232 	struct sparse_block *p;
2233 
2234 	p = (struct sparse_block *)calloc(1, sizeof(*p));
2235 	if (p == NULL) {
2236 		archive_set_error(&a->archive, ENOMEM, "Out of memory");
2237 		return (ARCHIVE_FATAL);
2238 	}
2239 	if (tar->sparse_last != NULL)
2240 		tar->sparse_last->next = p;
2241 	else
2242 		tar->sparse_list = p;
2243 	tar->sparse_last = p;
2244 	if (remaining < 0 || offset < 0 || offset > INT64_MAX - remaining) {
2245 		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Malformed sparse map data");
2246 		return (ARCHIVE_FATAL);
2247 	}
2248 	p->offset = offset;
2249 	p->remaining = remaining;
2250 	return (ARCHIVE_OK);
2251 }
2252 
2253 static void
2254 gnu_clear_sparse_list(struct tar *tar)
2255 {
2256 	struct sparse_block *p;
2257 
2258 	while (tar->sparse_list != NULL) {
2259 		p = tar->sparse_list;
2260 		tar->sparse_list = p->next;
2261 		free(p);
2262 	}
2263 	tar->sparse_last = NULL;
2264 }
2265 
2266 /*
2267  * GNU tar old-format sparse data.
2268  *
2269  * GNU old-format sparse data is stored in a fixed-field
2270  * format.  Offset/size values are 11-byte octal fields (same
2271  * format as 'size' field in ustart header).  These are
2272  * stored in the header, allocating subsequent header blocks
2273  * as needed.  Extending the header in this way is a pretty
2274  * severe POSIX violation; this design has earned GNU tar a
2275  * lot of criticism.
2276  */
2277 
2278 static int
2279 gnu_sparse_old_read(struct archive_read *a, struct tar *tar,
2280     const struct archive_entry_header_gnutar *header, size_t *unconsumed)
2281 {
2282 	ssize_t bytes_read;
2283 	const void *data;
2284 	struct extended {
2285 		struct gnu_sparse sparse[21];
2286 		char	isextended[1];
2287 		char	padding[7];
2288 	};
2289 	const struct extended *ext;
2290 
2291 	if (gnu_sparse_old_parse(a, tar, header->sparse, 4) != ARCHIVE_OK)
2292 		return (ARCHIVE_FATAL);
2293 	if (header->isextended[0] == 0)
2294 		return (ARCHIVE_OK);
2295 
2296 	do {
2297 		tar_flush_unconsumed(a, unconsumed);
2298 		data = __archive_read_ahead(a, 512, &bytes_read);
2299 		if (bytes_read < 0)
2300 			return (ARCHIVE_FATAL);
2301 		if (bytes_read < 512) {
2302 			archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
2303 			    "Truncated tar archive "
2304 			    "detected while reading sparse file data");
2305 			return (ARCHIVE_FATAL);
2306 		}
2307 		*unconsumed = 512;
2308 		ext = (const struct extended *)data;
2309 		if (gnu_sparse_old_parse(a, tar, ext->sparse, 21) != ARCHIVE_OK)
2310 			return (ARCHIVE_FATAL);
2311 	} while (ext->isextended[0] != 0);
2312 	if (tar->sparse_list != NULL)
2313 		tar->entry_offset = tar->sparse_list->offset;
2314 	return (ARCHIVE_OK);
2315 }
2316 
2317 static int
2318 gnu_sparse_old_parse(struct archive_read *a, struct tar *tar,
2319     const struct gnu_sparse *sparse, int length)
2320 {
2321 	while (length > 0 && sparse->offset[0] != 0) {
2322 		if (gnu_add_sparse_entry(a, tar,
2323 		    tar_atol(sparse->offset, sizeof(sparse->offset)),
2324 		    tar_atol(sparse->numbytes, sizeof(sparse->numbytes)))
2325 		    != ARCHIVE_OK)
2326 			return (ARCHIVE_FATAL);
2327 		sparse++;
2328 		length--;
2329 	}
2330 	return (ARCHIVE_OK);
2331 }
2332 
2333 /*
2334  * GNU tar sparse format 0.0
2335  *
2336  * Beginning with GNU tar 1.15, sparse files are stored using
2337  * information in the pax extended header.  The GNU tar maintainers
2338  * have gone through a number of variations in the process of working
2339  * out this scheme; fortunately, they're all numbered.
2340  *
2341  * Sparse format 0.0 uses attribute GNU.sparse.numblocks to store the
2342  * number of blocks, and GNU.sparse.offset/GNU.sparse.numbytes to
2343  * store offset/size for each block.  The repeated instances of these
2344  * latter fields violate the pax specification (which frowns on
2345  * duplicate keys), so this format was quickly replaced.
2346  */
2347 
2348 /*
2349  * GNU tar sparse format 0.1
2350  *
2351  * This version replaced the offset/numbytes attributes with
2352  * a single "map" attribute that stored a list of integers.  This
2353  * format had two problems: First, the "map" attribute could be very
2354  * long, which caused problems for some implementations.  More
2355  * importantly, the sparse data was lost when extracted by archivers
2356  * that didn't recognize this extension.
2357  */
2358 
2359 static int
2360 gnu_sparse_01_parse(struct archive_read *a, struct tar *tar, const char *p)
2361 {
2362 	const char *e;
2363 	int64_t offset = -1, size = -1;
2364 
2365 	for (;;) {
2366 		e = p;
2367 		while (*e != '\0' && *e != ',') {
2368 			if (*e < '0' || *e > '9')
2369 				return (ARCHIVE_WARN);
2370 			e++;
2371 		}
2372 		if (offset < 0) {
2373 			offset = tar_atol10(p, e - p);
2374 			if (offset < 0)
2375 				return (ARCHIVE_WARN);
2376 		} else {
2377 			size = tar_atol10(p, e - p);
2378 			if (size < 0)
2379 				return (ARCHIVE_WARN);
2380 			if (gnu_add_sparse_entry(a, tar, offset, size)
2381 			    != ARCHIVE_OK)
2382 				return (ARCHIVE_FATAL);
2383 			offset = -1;
2384 		}
2385 		if (*e == '\0')
2386 			return (ARCHIVE_OK);
2387 		p = e + 1;
2388 	}
2389 }
2390 
2391 /*
2392  * GNU tar sparse format 1.0
2393  *
2394  * The idea: The offset/size data is stored as a series of base-10
2395  * ASCII numbers prepended to the file data, so that dearchivers that
2396  * don't support this format will extract the block map along with the
2397  * data and a separate post-process can restore the sparseness.
2398  *
2399  * Unfortunately, GNU tar 1.16 had a bug that added unnecessary
2400  * padding to the body of the file when using this format.  GNU tar
2401  * 1.17 corrected this bug without bumping the version number, so
2402  * it's not possible to support both variants.  This code supports
2403  * the later variant at the expense of not supporting the former.
2404  *
2405  * This variant also replaced GNU.sparse.size with GNU.sparse.realsize
2406  * and introduced the GNU.sparse.major/GNU.sparse.minor attributes.
2407  */
2408 
2409 /*
2410  * Read the next line from the input, and parse it as a decimal
2411  * integer followed by '\n'.  Returns positive integer value or
2412  * negative on error.
2413  */
2414 static int64_t
2415 gnu_sparse_10_atol(struct archive_read *a, struct tar *tar,
2416     int64_t *remaining, size_t *unconsumed)
2417 {
2418 	int64_t l, limit, last_digit_limit;
2419 	const char *p;
2420 	ssize_t bytes_read;
2421 	int base, digit;
2422 
2423 	base = 10;
2424 	limit = INT64_MAX / base;
2425 	last_digit_limit = INT64_MAX % base;
2426 
2427 	/*
2428 	 * Skip any lines starting with '#'; GNU tar specs
2429 	 * don't require this, but they should.
2430 	 */
2431 	do {
2432 		bytes_read = readline(a, tar, &p,
2433 			(ssize_t)tar_min(*remaining, 100), unconsumed);
2434 		if (bytes_read <= 0)
2435 			return (ARCHIVE_FATAL);
2436 		*remaining -= bytes_read;
2437 	} while (p[0] == '#');
2438 
2439 	l = 0;
2440 	while (bytes_read > 0) {
2441 		if (*p == '\n')
2442 			return (l);
2443 		if (*p < '0' || *p >= '0' + base)
2444 			return (ARCHIVE_WARN);
2445 		digit = *p - '0';
2446 		if (l > limit || (l == limit && digit > last_digit_limit))
2447 			l = INT64_MAX; /* Truncate on overflow. */
2448 		else
2449 			l = (l * base) + digit;
2450 		p++;
2451 		bytes_read--;
2452 	}
2453 	/* TODO: Error message. */
2454 	return (ARCHIVE_WARN);
2455 }
2456 
2457 /*
2458  * Returns length (in bytes) of the sparse data description
2459  * that was read.
2460  */
2461 static ssize_t
2462 gnu_sparse_10_read(struct archive_read *a, struct tar *tar, size_t *unconsumed)
2463 {
2464 	ssize_t bytes_read;
2465 	int entries;
2466 	int64_t offset, size, to_skip, remaining;
2467 
2468 	/* Clear out the existing sparse list. */
2469 	gnu_clear_sparse_list(tar);
2470 
2471 	remaining = tar->entry_bytes_remaining;
2472 
2473 	/* Parse entries. */
2474 	entries = (int)gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2475 	if (entries < 0)
2476 		return (ARCHIVE_FATAL);
2477 	/* Parse the individual entries. */
2478 	while (entries-- > 0) {
2479 		/* Parse offset/size */
2480 		offset = gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2481 		if (offset < 0)
2482 			return (ARCHIVE_FATAL);
2483 		size = gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2484 		if (size < 0)
2485 			return (ARCHIVE_FATAL);
2486 		/* Add a new sparse entry. */
2487 		if (gnu_add_sparse_entry(a, tar, offset, size) != ARCHIVE_OK)
2488 			return (ARCHIVE_FATAL);
2489 	}
2490 	/* Skip rest of block... */
2491 	tar_flush_unconsumed(a, unconsumed);
2492 	bytes_read = (ssize_t)(tar->entry_bytes_remaining - remaining);
2493 	to_skip = 0x1ff & -bytes_read;
2494 	/* Fail if tar->entry_bytes_remaing would get negative */
2495 	if (to_skip > remaining)
2496 		return (ARCHIVE_FATAL);
2497 	if (to_skip != __archive_read_consume(a, to_skip))
2498 		return (ARCHIVE_FATAL);
2499 	return ((ssize_t)(bytes_read + to_skip));
2500 }
2501 
2502 /*
2503  * Solaris pax extension for a sparse file. This is recorded with the
2504  * data and hole pairs. The way recording sparse information by Solaris'
2505  * pax simply indicates where data and sparse are, so the stored contents
2506  * consist of both data and hole.
2507  */
2508 static int
2509 solaris_sparse_parse(struct archive_read *a, struct tar *tar,
2510     struct archive_entry *entry, const char *p)
2511 {
2512 	const char *e;
2513 	int64_t start, end;
2514 	int hole = 1;
2515 
2516 	(void)entry; /* UNUSED */
2517 
2518 	end = 0;
2519 	if (*p == ' ')
2520 		p++;
2521 	else
2522 		return (ARCHIVE_WARN);
2523 	for (;;) {
2524 		e = p;
2525 		while (*e != '\0' && *e != ' ') {
2526 			if (*e < '0' || *e > '9')
2527 				return (ARCHIVE_WARN);
2528 			e++;
2529 		}
2530 		start = end;
2531 		end = tar_atol10(p, e - p);
2532 		if (end < 0)
2533 			return (ARCHIVE_WARN);
2534 		if (start < end) {
2535 			if (gnu_add_sparse_entry(a, tar, start,
2536 			    end - start) != ARCHIVE_OK)
2537 				return (ARCHIVE_FATAL);
2538 			tar->sparse_last->hole = hole;
2539 		}
2540 		if (*e == '\0')
2541 			return (ARCHIVE_OK);
2542 		p = e + 1;
2543 		hole = hole == 0;
2544 	}
2545 }
2546 
2547 /*-
2548  * Convert text->integer.
2549  *
2550  * Traditional tar formats (including POSIX) specify base-8 for
2551  * all of the standard numeric fields.  This is a significant limitation
2552  * in practice:
2553  *   = file size is limited to 8GB
2554  *   = rdevmajor and rdevminor are limited to 21 bits
2555  *   = uid/gid are limited to 21 bits
2556  *
2557  * There are two workarounds for this:
2558  *   = pax extended headers, which use variable-length string fields
2559  *   = GNU tar and STAR both allow either base-8 or base-256 in
2560  *      most fields.  The high bit is set to indicate base-256.
2561  *
2562  * On read, this implementation supports both extensions.
2563  */
2564 static int64_t
2565 tar_atol(const char *p, size_t char_cnt)
2566 {
2567 	/*
2568 	 * Technically, GNU tar considers a field to be in base-256
2569 	 * only if the first byte is 0xff or 0x80.
2570 	 */
2571 	if (*p & 0x80)
2572 		return (tar_atol256(p, char_cnt));
2573 	return (tar_atol8(p, char_cnt));
2574 }
2575 
2576 /*
2577  * Note that this implementation does not (and should not!) obey
2578  * locale settings; you cannot simply substitute strtol here, since
2579  * it does obey locale.
2580  */
2581 static int64_t
2582 tar_atol_base_n(const char *p, size_t char_cnt, int base)
2583 {
2584 	int64_t	l, maxval, limit, last_digit_limit;
2585 	int digit, sign;
2586 
2587 	maxval = INT64_MAX;
2588 	limit = INT64_MAX / base;
2589 	last_digit_limit = INT64_MAX % base;
2590 
2591 	/* the pointer will not be dereferenced if char_cnt is zero
2592 	 * due to the way the && operator is evaluated.
2593 	 */
2594 	while (char_cnt != 0 && (*p == ' ' || *p == '\t')) {
2595 		p++;
2596 		char_cnt--;
2597 	}
2598 
2599 	sign = 1;
2600 	if (char_cnt != 0 && *p == '-') {
2601 		sign = -1;
2602 		p++;
2603 		char_cnt--;
2604 
2605 		maxval = INT64_MIN;
2606 		limit = -(INT64_MIN / base);
2607 		last_digit_limit = INT64_MIN % base;
2608 	}
2609 
2610 	l = 0;
2611 	if (char_cnt != 0) {
2612 		digit = *p - '0';
2613 		while (digit >= 0 && digit < base  && char_cnt != 0) {
2614 			if (l>limit || (l == limit && digit > last_digit_limit)) {
2615 				return maxval; /* Truncate on overflow. */
2616 			}
2617 			l = (l * base) + digit;
2618 			digit = *++p - '0';
2619 			char_cnt--;
2620 		}
2621 	}
2622 	return (sign < 0) ? -l : l;
2623 }
2624 
2625 static int64_t
2626 tar_atol8(const char *p, size_t char_cnt)
2627 {
2628 	return tar_atol_base_n(p, char_cnt, 8);
2629 }
2630 
2631 static int64_t
2632 tar_atol10(const char *p, size_t char_cnt)
2633 {
2634 	return tar_atol_base_n(p, char_cnt, 10);
2635 }
2636 
2637 /*
2638  * Parse a base-256 integer.  This is just a variable-length
2639  * twos-complement signed binary value in big-endian order, except
2640  * that the high-order bit is ignored.  The values here can be up to
2641  * 12 bytes, so we need to be careful about overflowing 64-bit
2642  * (8-byte) integers.
2643  *
2644  * This code unashamedly assumes that the local machine uses 8-bit
2645  * bytes and twos-complement arithmetic.
2646  */
2647 static int64_t
2648 tar_atol256(const char *_p, size_t char_cnt)
2649 {
2650 	uint64_t l;
2651 	const unsigned char *p = (const unsigned char *)_p;
2652 	unsigned char c, neg;
2653 
2654 	/* Extend 7-bit 2s-comp to 8-bit 2s-comp, decide sign. */
2655 	c = *p;
2656 	if (c & 0x40) {
2657 		neg = 0xff;
2658 		c |= 0x80;
2659 		l = ~ARCHIVE_LITERAL_ULL(0);
2660 	} else {
2661 		neg = 0;
2662 		c &= 0x7f;
2663 		l = 0;
2664 	}
2665 
2666 	/* If more than 8 bytes, check that we can ignore
2667 	 * high-order bits without overflow. */
2668 	while (char_cnt > sizeof(int64_t)) {
2669 		--char_cnt;
2670 		if (c != neg)
2671 			return neg ? INT64_MIN : INT64_MAX;
2672 		c = *++p;
2673 	}
2674 
2675 	/* c is first byte that fits; if sign mismatch, return overflow */
2676 	if ((c ^ neg) & 0x80) {
2677 		return neg ? INT64_MIN : INT64_MAX;
2678 	}
2679 
2680 	/* Accumulate remaining bytes. */
2681 	while (--char_cnt > 0) {
2682 		l = (l << 8) | c;
2683 		c = *++p;
2684 	}
2685 	l = (l << 8) | c;
2686 	/* Return signed twos-complement value. */
2687 	return (int64_t)(l);
2688 }
2689 
2690 /*
2691  * Returns length of line (including trailing newline)
2692  * or negative on error.  'start' argument is updated to
2693  * point to first character of line.  This avoids copying
2694  * when possible.
2695  */
2696 static ssize_t
2697 readline(struct archive_read *a, struct tar *tar, const char **start,
2698     ssize_t limit, size_t *unconsumed)
2699 {
2700 	ssize_t bytes_read;
2701 	ssize_t total_size = 0;
2702 	const void *t;
2703 	const char *s;
2704 	void *p;
2705 
2706 	tar_flush_unconsumed(a, unconsumed);
2707 
2708 	t = __archive_read_ahead(a, 1, &bytes_read);
2709 	if (bytes_read <= 0)
2710 		return (ARCHIVE_FATAL);
2711 	s = t;  /* Start of line? */
2712 	p = memchr(t, '\n', bytes_read);
2713 	/* If we found '\n' in the read buffer, return pointer to that. */
2714 	if (p != NULL) {
2715 		bytes_read = 1 + ((const char *)p) - s;
2716 		if (bytes_read > limit) {
2717 			archive_set_error(&a->archive,
2718 			    ARCHIVE_ERRNO_FILE_FORMAT,
2719 			    "Line too long");
2720 			return (ARCHIVE_FATAL);
2721 		}
2722 		*unconsumed = bytes_read;
2723 		*start = s;
2724 		return (bytes_read);
2725 	}
2726 	*unconsumed = bytes_read;
2727 	/* Otherwise, we need to accumulate in a line buffer. */
2728 	for (;;) {
2729 		if (total_size + bytes_read > limit) {
2730 			archive_set_error(&a->archive,
2731 			    ARCHIVE_ERRNO_FILE_FORMAT,
2732 			    "Line too long");
2733 			return (ARCHIVE_FATAL);
2734 		}
2735 		if (archive_string_ensure(&tar->line, total_size + bytes_read) == NULL) {
2736 			archive_set_error(&a->archive, ENOMEM,
2737 			    "Can't allocate working buffer");
2738 			return (ARCHIVE_FATAL);
2739 		}
2740 		memcpy(tar->line.s + total_size, t, bytes_read);
2741 		tar_flush_unconsumed(a, unconsumed);
2742 		total_size += bytes_read;
2743 		/* If we found '\n', clean up and return. */
2744 		if (p != NULL) {
2745 			*start = tar->line.s;
2746 			return (total_size);
2747 		}
2748 		/* Read some more. */
2749 		t = __archive_read_ahead(a, 1, &bytes_read);
2750 		if (bytes_read <= 0)
2751 			return (ARCHIVE_FATAL);
2752 		s = t;  /* Start of line? */
2753 		p = memchr(t, '\n', bytes_read);
2754 		/* If we found '\n', trim the read. */
2755 		if (p != NULL) {
2756 			bytes_read = 1 + ((const char *)p) - s;
2757 		}
2758 		*unconsumed = bytes_read;
2759 	}
2760 }
2761 
2762 /*
2763  * base64_decode - Base64 decode
2764  *
2765  * This accepts most variations of base-64 encoding, including:
2766  *    * with or without line breaks
2767  *    * with or without the final group padded with '=' or '_' characters
2768  * (The most economical Base-64 variant does not pad the last group and
2769  * omits line breaks; RFC1341 used for MIME requires both.)
2770  */
2771 static char *
2772 base64_decode(const char *s, size_t len, size_t *out_len)
2773 {
2774 	static const unsigned char digits[64] = {
2775 		'A','B','C','D','E','F','G','H','I','J','K','L','M','N',
2776 		'O','P','Q','R','S','T','U','V','W','X','Y','Z','a','b',
2777 		'c','d','e','f','g','h','i','j','k','l','m','n','o','p',
2778 		'q','r','s','t','u','v','w','x','y','z','0','1','2','3',
2779 		'4','5','6','7','8','9','+','/' };
2780 	static unsigned char decode_table[128];
2781 	char *out, *d;
2782 	const unsigned char *src = (const unsigned char *)s;
2783 
2784 	/* If the decode table is not yet initialized, prepare it. */
2785 	if (decode_table[digits[1]] != 1) {
2786 		unsigned i;
2787 		memset(decode_table, 0xff, sizeof(decode_table));
2788 		for (i = 0; i < sizeof(digits); i++)
2789 			decode_table[digits[i]] = i;
2790 	}
2791 
2792 	/* Allocate enough space to hold the entire output. */
2793 	/* Note that we may not use all of this... */
2794 	out = (char *)malloc(len - len / 4 + 1);
2795 	if (out == NULL) {
2796 		*out_len = 0;
2797 		return (NULL);
2798 	}
2799 	d = out;
2800 
2801 	while (len > 0) {
2802 		/* Collect the next group of (up to) four characters. */
2803 		int v = 0;
2804 		int group_size = 0;
2805 		while (group_size < 4 && len > 0) {
2806 			/* '=' or '_' padding indicates final group. */
2807 			if (*src == '=' || *src == '_') {
2808 				len = 0;
2809 				break;
2810 			}
2811 			/* Skip illegal characters (including line breaks) */
2812 			if (*src > 127 || *src < 32
2813 			    || decode_table[*src] == 0xff) {
2814 				len--;
2815 				src++;
2816 				continue;
2817 			}
2818 			v <<= 6;
2819 			v |= decode_table[*src++];
2820 			len --;
2821 			group_size++;
2822 		}
2823 		/* Align a short group properly. */
2824 		v <<= 6 * (4 - group_size);
2825 		/* Unpack the group we just collected. */
2826 		switch (group_size) {
2827 		case 4: d[2] = v & 0xff;
2828 			/* FALLTHROUGH */
2829 		case 3: d[1] = (v >> 8) & 0xff;
2830 			/* FALLTHROUGH */
2831 		case 2: d[0] = (v >> 16) & 0xff;
2832 			break;
2833 		case 1: /* this is invalid! */
2834 			break;
2835 		}
2836 		d += group_size * 3 / 4;
2837 	}
2838 
2839 	*out_len = d - out;
2840 	return (out);
2841 }
2842 
2843 static char *
2844 url_decode(const char *in)
2845 {
2846 	char *out, *d;
2847 	const char *s;
2848 
2849 	out = (char *)malloc(strlen(in) + 1);
2850 	if (out == NULL)
2851 		return (NULL);
2852 	for (s = in, d = out; *s != '\0'; ) {
2853 		if (s[0] == '%' && s[1] != '\0' && s[2] != '\0') {
2854 			/* Try to convert % escape */
2855 			int digit1 = tohex(s[1]);
2856 			int digit2 = tohex(s[2]);
2857 			if (digit1 >= 0 && digit2 >= 0) {
2858 				/* Looks good, consume three chars */
2859 				s += 3;
2860 				/* Convert output */
2861 				*d++ = ((digit1 << 4) | digit2);
2862 				continue;
2863 			}
2864 			/* Else fall through and treat '%' as normal char */
2865 		}
2866 		*d++ = *s++;
2867 	}
2868 	*d = '\0';
2869 	return (out);
2870 }
2871 
2872 static int
2873 tohex(int c)
2874 {
2875 	if (c >= '0' && c <= '9')
2876 		return (c - '0');
2877 	else if (c >= 'A' && c <= 'F')
2878 		return (c - 'A' + 10);
2879 	else if (c >= 'a' && c <= 'f')
2880 		return (c - 'a' + 10);
2881 	else
2882 		return (-1);
2883 }
2884