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
30#ifdef HAVE_ERRNO_H
31#include <errno.h>
32#endif
33#include <stddef.h>
34#ifdef HAVE_STDLIB_H
35#include <stdlib.h>
36#endif
37#ifdef HAVE_STRING_H
38#include <string.h>
39#endif
40
41#include "archive.h"
42#include "archive_acl_private.h" /* For ACL parsing routines. */
43#include "archive_entry.h"
44#include "archive_entry_locale.h"
45#include "archive_private.h"
46#include "archive_read_private.h"
47
48#define tar_min(a,b) ((a) < (b) ? (a) : (b))
49
50/*
51 * Layout of POSIX 'ustar' tar header.
52 */
53struct archive_entry_header_ustar {
54	char	name[100];
55	char	mode[8];
56	char	uid[8];
57	char	gid[8];
58	char	size[12];
59	char	mtime[12];
60	char	checksum[8];
61	char	typeflag[1];
62	char	linkname[100];	/* "old format" header ends here */
63	char	magic[6];	/* For POSIX: "ustar\0" */
64	char	version[2];	/* For POSIX: "00" */
65	char	uname[32];
66	char	gname[32];
67	char	rdevmajor[8];
68	char	rdevminor[8];
69	char	prefix[155];
70};
71
72/*
73 * Structure of GNU tar header
74 */
75struct gnu_sparse {
76	char	offset[12];
77	char	numbytes[12];
78};
79
80struct archive_entry_header_gnutar {
81	char	name[100];
82	char	mode[8];
83	char	uid[8];
84	char	gid[8];
85	char	size[12];
86	char	mtime[12];
87	char	checksum[8];
88	char	typeflag[1];
89	char	linkname[100];
90	char	magic[8];  /* "ustar  \0" (note blank/blank/null at end) */
91	char	uname[32];
92	char	gname[32];
93	char	rdevmajor[8];
94	char	rdevminor[8];
95	char	atime[12];
96	char	ctime[12];
97	char	offset[12];
98	char	longnames[4];
99	char	unused[1];
100	struct gnu_sparse sparse[4];
101	char	isextended[1];
102	char	realsize[12];
103	/*
104	 * Old GNU format doesn't use POSIX 'prefix' field; they use
105	 * the 'L' (longname) entry instead.
106	 */
107};
108
109/*
110 * Data specific to this format.
111 */
112struct sparse_block {
113	struct sparse_block	*next;
114	int64_t	offset;
115	int64_t	remaining;
116	int hole;
117};
118
119struct tar {
120	struct archive_string	 acl_text;
121	struct archive_string	 entry_pathname;
122	/* For "GNU.sparse.name" and other similar path extensions. */
123	struct archive_string	 entry_pathname_override;
124	struct archive_string	 entry_linkpath;
125	struct archive_string	 entry_uname;
126	struct archive_string	 entry_gname;
127	struct archive_string	 longlink;
128	struct archive_string	 longname;
129	struct archive_string	 pax_header;
130	struct archive_string	 pax_global;
131	struct archive_string	 line;
132	int			 pax_hdrcharset_binary;
133	int			 header_recursion_depth;
134	int64_t			 entry_bytes_remaining;
135	int64_t			 entry_offset;
136	int64_t			 entry_padding;
137	int64_t 		 entry_bytes_unconsumed;
138	int64_t			 realsize;
139	int			 sparse_allowed;
140	struct sparse_block	*sparse_list;
141	struct sparse_block	*sparse_last;
142	int64_t			 sparse_offset;
143	int64_t			 sparse_numbytes;
144	int			 sparse_gnu_major;
145	int			 sparse_gnu_minor;
146	char			 sparse_gnu_pending;
147
148	struct archive_string	 localname;
149	struct archive_string_conv *opt_sconv;
150	struct archive_string_conv *sconv;
151	struct archive_string_conv *sconv_acl;
152	struct archive_string_conv *sconv_default;
153	int			 init_default_conversion;
154	int			 compat_2x;
155	int			 process_mac_extensions;
156	int			 read_concatenated_archives;
157	int			 realsize_override;
158};
159
160static int	archive_block_is_null(const char *p);
161static char	*base64_decode(const char *, size_t, size_t *);
162static int	gnu_add_sparse_entry(struct archive_read *, struct tar *,
163		    int64_t offset, int64_t remaining);
164
165static void	gnu_clear_sparse_list(struct tar *);
166static int	gnu_sparse_old_read(struct archive_read *, struct tar *,
167		    const struct archive_entry_header_gnutar *header, size_t *);
168static int	gnu_sparse_old_parse(struct archive_read *, struct tar *,
169		    const struct gnu_sparse *sparse, int length);
170static int	gnu_sparse_01_parse(struct archive_read *, struct tar *,
171		    const char *);
172static ssize_t	gnu_sparse_10_read(struct archive_read *, struct tar *,
173			size_t *);
174static int	header_Solaris_ACL(struct archive_read *,  struct tar *,
175		    struct archive_entry *, const void *, size_t *);
176static int	header_common(struct archive_read *,  struct tar *,
177		    struct archive_entry *, const void *);
178static int	header_old_tar(struct archive_read *, struct tar *,
179		    struct archive_entry *, const void *);
180static int	header_pax_extensions(struct archive_read *, struct tar *,
181		    struct archive_entry *, const void *, size_t *);
182static int	header_pax_global(struct archive_read *, struct tar *,
183		    struct archive_entry *, const void *h, size_t *);
184static int	header_longlink(struct archive_read *, struct tar *,
185		    struct archive_entry *, const void *h, size_t *);
186static int	header_longname(struct archive_read *, struct tar *,
187		    struct archive_entry *, const void *h, size_t *);
188static int	read_mac_metadata_blob(struct archive_read *, struct tar *,
189		    struct archive_entry *, const void *h, size_t *);
190static int	header_volume(struct archive_read *, struct tar *,
191		    struct archive_entry *, const void *h, size_t *);
192static int	header_ustar(struct archive_read *, struct tar *,
193		    struct archive_entry *, const void *h);
194static int	header_gnutar(struct archive_read *, struct tar *,
195		    struct archive_entry *, const void *h, size_t *);
196static int	archive_read_format_tar_bid(struct archive_read *, int);
197static int	archive_read_format_tar_options(struct archive_read *,
198		    const char *, const char *);
199static int	archive_read_format_tar_cleanup(struct archive_read *);
200static int	archive_read_format_tar_read_data(struct archive_read *a,
201		    const void **buff, size_t *size, int64_t *offset);
202static int	archive_read_format_tar_skip(struct archive_read *a);
203static int	archive_read_format_tar_read_header(struct archive_read *,
204		    struct archive_entry *);
205static int	checksum(struct archive_read *, const void *);
206static int 	pax_attribute(struct archive_read *, struct tar *,
207		    struct archive_entry *, const char *key, const char *value,
208		    size_t value_length);
209static int	pax_attribute_acl(struct archive_read *, struct tar *,
210		    struct archive_entry *, const char *, int);
211static int	pax_attribute_xattr(struct archive_entry *, const char *,
212		    const char *);
213static int 	pax_header(struct archive_read *, struct tar *,
214		    struct archive_entry *, struct archive_string *);
215static void	pax_time(const char *, int64_t *sec, long *nanos);
216static ssize_t	readline(struct archive_read *, struct tar *, const char **,
217		    ssize_t limit, size_t *);
218static int	read_body_to_string(struct archive_read *, struct tar *,
219		    struct archive_string *, const void *h, size_t *);
220static int	solaris_sparse_parse(struct archive_read *, struct tar *,
221		    struct archive_entry *, const char *);
222static int64_t	tar_atol(const char *, size_t);
223static int64_t	tar_atol10(const char *, size_t);
224static int64_t	tar_atol256(const char *, size_t);
225static int64_t	tar_atol8(const char *, size_t);
226static int	tar_read_header(struct archive_read *, struct tar *,
227		    struct archive_entry *, size_t *);
228static int	tohex(int c);
229static char	*url_decode(const char *);
230static void	tar_flush_unconsumed(struct archive_read *, size_t *);
231
232
233int
234archive_read_support_format_gnutar(struct archive *a)
235{
236	archive_check_magic(a, ARCHIVE_READ_MAGIC,
237	    ARCHIVE_STATE_NEW, "archive_read_support_format_gnutar");
238	return (archive_read_support_format_tar(a));
239}
240
241
242int
243archive_read_support_format_tar(struct archive *_a)
244{
245	struct archive_read *a = (struct archive_read *)_a;
246	struct tar *tar;
247	int r;
248
249	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
250	    ARCHIVE_STATE_NEW, "archive_read_support_format_tar");
251
252	tar = (struct tar *)calloc(1, sizeof(*tar));
253	if (tar == NULL) {
254		archive_set_error(&a->archive, ENOMEM,
255		    "Can't allocate tar data");
256		return (ARCHIVE_FATAL);
257	}
258#ifdef HAVE_COPYFILE_H
259	/* Set this by default on Mac OS. */
260	tar->process_mac_extensions = 1;
261#endif
262
263	r = __archive_read_register_format(a, tar, "tar",
264	    archive_read_format_tar_bid,
265	    archive_read_format_tar_options,
266	    archive_read_format_tar_read_header,
267	    archive_read_format_tar_read_data,
268	    archive_read_format_tar_skip,
269	    NULL,
270	    archive_read_format_tar_cleanup,
271	    NULL,
272	    NULL);
273
274	if (r != ARCHIVE_OK)
275		free(tar);
276	return (ARCHIVE_OK);
277}
278
279static int
280archive_read_format_tar_cleanup(struct archive_read *a)
281{
282	struct tar *tar;
283
284	tar = (struct tar *)(a->format->data);
285	gnu_clear_sparse_list(tar);
286	archive_string_free(&tar->acl_text);
287	archive_string_free(&tar->entry_pathname);
288	archive_string_free(&tar->entry_pathname_override);
289	archive_string_free(&tar->entry_linkpath);
290	archive_string_free(&tar->entry_uname);
291	archive_string_free(&tar->entry_gname);
292	archive_string_free(&tar->line);
293	archive_string_free(&tar->pax_global);
294	archive_string_free(&tar->pax_header);
295	archive_string_free(&tar->longname);
296	archive_string_free(&tar->longlink);
297	archive_string_free(&tar->localname);
298	free(tar);
299	(a->format->data) = NULL;
300	return (ARCHIVE_OK);
301}
302
303/*
304 * Validate number field
305 *
306 * This has to be pretty lenient in order to accommodate the enormous
307 * variety of tar writers in the world:
308 *  = POSIX (IEEE Std 1003.1-1988) ustar requires octal values with leading
309 *    zeros and allows fields to be terminated with space or null characters
310 *  = Many writers use different termination (in particular, libarchive
311 *    omits terminator bytes to squeeze one or two more digits)
312 *  = Many writers pad with space and omit leading zeros
313 *  = GNU tar and star write base-256 values if numbers are too
314 *    big to be represented in octal
315 *
316 *  Examples of specific tar headers that we should support:
317 *  = Perl Archive::Tar terminates uid, gid, devminor and devmajor with two
318 *    null bytes, pads size with spaces and other numeric fields with zeroes
319 *  = plexus-archiver prior to 2.6.3 (before switching to commons-compress)
320 *    may have uid and gid fields filled with spaces without any octal digits
321 *    at all and pads all numeric fields with spaces
322 *
323 * This should tolerate all variants in use.  It will reject a field
324 * where the writer just left garbage after a trailing NUL.
325 */
326static int
327validate_number_field(const char* p_field, size_t i_size)
328{
329	unsigned char marker = (unsigned char)p_field[0];
330	if (marker == 128 || marker == 255 || marker == 0) {
331		/* Base-256 marker, there's nothing we can check. */
332		return 1;
333	} else {
334		/* Must be octal */
335		size_t i = 0;
336		/* Skip any leading spaces */
337		while (i < i_size && p_field[i] == ' ') {
338			++i;
339		}
340		/* Skip octal digits. */
341		while (i < i_size && p_field[i] >= '0' && p_field[i] <= '7') {
342			++i;
343		}
344		/* Any remaining characters must be space or NUL padding. */
345		while (i < i_size) {
346			if (p_field[i] != ' ' && p_field[i] != 0) {
347				return 0;
348			}
349			++i;
350		}
351		return 1;
352	}
353}
354
355static int
356archive_read_format_tar_bid(struct archive_read *a, int best_bid)
357{
358	int bid;
359	const char *h;
360	const struct archive_entry_header_ustar *header;
361
362	(void)best_bid; /* UNUSED */
363
364	bid = 0;
365
366	/* Now let's look at the actual header and see if it matches. */
367	h = __archive_read_ahead(a, 512, NULL);
368	if (h == NULL)
369		return (-1);
370
371	/* If it's an end-of-archive mark, we can handle it. */
372	if (h[0] == 0 && archive_block_is_null(h)) {
373		/*
374		 * Usually, I bid the number of bits verified, but
375		 * in this case, 4096 seems excessive so I picked 10 as
376		 * an arbitrary but reasonable-seeming value.
377		 */
378		return (10);
379	}
380
381	/* If it's not an end-of-archive mark, it must have a valid checksum.*/
382	if (!checksum(a, h))
383		return (0);
384	bid += 48;  /* Checksum is usually 6 octal digits. */
385
386	header = (const struct archive_entry_header_ustar *)h;
387
388	/* Recognize POSIX formats. */
389	if ((memcmp(header->magic, "ustar\0", 6) == 0)
390	    && (memcmp(header->version, "00", 2) == 0))
391		bid += 56;
392
393	/* Recognize GNU tar format. */
394	if ((memcmp(header->magic, "ustar ", 6) == 0)
395	    && (memcmp(header->version, " \0", 2) == 0))
396		bid += 56;
397
398	/* Type flag must be null, digit or A-Z, a-z. */
399	if (header->typeflag[0] != 0 &&
400	    !( header->typeflag[0] >= '0' && header->typeflag[0] <= '9') &&
401	    !( header->typeflag[0] >= 'A' && header->typeflag[0] <= 'Z') &&
402	    !( header->typeflag[0] >= 'a' && header->typeflag[0] <= 'z') )
403		return (0);
404	bid += 2;  /* 6 bits of variation in an 8-bit field leaves 2 bits. */
405
406	/*
407	 * Check format of mode/uid/gid/mtime/size/rdevmajor/rdevminor fields.
408	 */
409	if (validate_number_field(header->mode, sizeof(header->mode)) == 0
410	    || validate_number_field(header->uid, sizeof(header->uid)) == 0
411	    || validate_number_field(header->gid, sizeof(header->gid)) == 0
412	    || validate_number_field(header->mtime, sizeof(header->mtime)) == 0
413	    || validate_number_field(header->size, sizeof(header->size)) == 0
414	    || validate_number_field(header->rdevmajor, sizeof(header->rdevmajor)) == 0
415	    || validate_number_field(header->rdevminor, sizeof(header->rdevminor)) == 0) {
416		bid = 0;
417	}
418
419	return (bid);
420}
421
422static int
423archive_read_format_tar_options(struct archive_read *a,
424    const char *key, const char *val)
425{
426	struct tar *tar;
427	int ret = ARCHIVE_FAILED;
428
429	tar = (struct tar *)(a->format->data);
430	if (strcmp(key, "compat-2x")  == 0) {
431		/* Handle UTF-8 filenames as libarchive 2.x */
432		tar->compat_2x = (val != NULL && val[0] != 0);
433		tar->init_default_conversion = tar->compat_2x;
434		return (ARCHIVE_OK);
435	} else if (strcmp(key, "hdrcharset")  == 0) {
436		if (val == NULL || val[0] == 0)
437			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
438			    "tar: hdrcharset option needs a character-set name");
439		else {
440			tar->opt_sconv =
441			    archive_string_conversion_from_charset(
442				&a->archive, val, 0);
443			if (tar->opt_sconv != NULL)
444				ret = ARCHIVE_OK;
445			else
446				ret = ARCHIVE_FATAL;
447		}
448		return (ret);
449	} else if (strcmp(key, "mac-ext") == 0) {
450		tar->process_mac_extensions = (val != NULL && val[0] != 0);
451		return (ARCHIVE_OK);
452	} else if (strcmp(key, "read_concatenated_archives") == 0) {
453		tar->read_concatenated_archives = (val != NULL && val[0] != 0);
454		return (ARCHIVE_OK);
455	}
456
457	/* Note: The "warn" return is just to inform the options
458	 * supervisor that we didn't handle it.  It will generate
459	 * a suitable error if no one used this option. */
460	return (ARCHIVE_WARN);
461}
462
463/* utility function- this exists to centralize the logic of tracking
464 * how much unconsumed data we have floating around, and to consume
465 * anything outstanding since we're going to do read_aheads
466 */
467static void
468tar_flush_unconsumed(struct archive_read *a, size_t *unconsumed)
469{
470	if (*unconsumed) {
471/*
472		void *data = (void *)__archive_read_ahead(a, *unconsumed, NULL);
473		 * this block of code is to poison claimed unconsumed space, ensuring
474		 * things break if it is in use still.
475		 * currently it WILL break things, so enable it only for debugging this issue
476		if (data) {
477			memset(data, 0xff, *unconsumed);
478		}
479*/
480		__archive_read_consume(a, *unconsumed);
481		*unconsumed = 0;
482	}
483}
484
485/*
486 * The function invoked by archive_read_next_header().  This
487 * just sets up a few things and then calls the internal
488 * tar_read_header() function below.
489 */
490static int
491archive_read_format_tar_read_header(struct archive_read *a,
492    struct archive_entry *entry)
493{
494	/*
495	 * When converting tar archives to cpio archives, it is
496	 * essential that each distinct file have a distinct inode
497	 * number.  To simplify this, we keep a static count here to
498	 * assign fake dev/inode numbers to each tar entry.  Note that
499	 * pax format archives may overwrite this with something more
500	 * useful.
501	 *
502	 * Ideally, we would track every file read from the archive so
503	 * that we could assign the same dev/ino pair to hardlinks,
504	 * but the memory required to store a complete lookup table is
505	 * probably not worthwhile just to support the relatively
506	 * obscure tar->cpio conversion case.
507	 */
508	static int default_inode;
509	static int default_dev;
510	struct tar *tar;
511	const char *p;
512	const wchar_t *wp;
513	int r;
514	size_t l, unconsumed = 0;
515
516	/* Assign default device/inode values. */
517	archive_entry_set_dev(entry, 1 + default_dev); /* Don't use zero. */
518	archive_entry_set_ino(entry, ++default_inode); /* Don't use zero. */
519	/* Limit generated st_ino number to 16 bits. */
520	if (default_inode >= 0xffff) {
521		++default_dev;
522		default_inode = 0;
523	}
524
525	tar = (struct tar *)(a->format->data);
526	tar->entry_offset = 0;
527	gnu_clear_sparse_list(tar);
528	tar->realsize = -1; /* Mark this as "unset" */
529	tar->realsize_override = 0;
530
531	/* Setup default string conversion. */
532	tar->sconv = tar->opt_sconv;
533	if (tar->sconv == NULL) {
534		if (!tar->init_default_conversion) {
535			tar->sconv_default =
536			    archive_string_default_conversion_for_read(&(a->archive));
537			tar->init_default_conversion = 1;
538		}
539		tar->sconv = tar->sconv_default;
540	}
541
542	r = tar_read_header(a, tar, entry, &unconsumed);
543
544	tar_flush_unconsumed(a, &unconsumed);
545
546	/*
547	 * "non-sparse" files are really just sparse files with
548	 * a single block.
549	 */
550	if (tar->sparse_list == NULL) {
551		if (gnu_add_sparse_entry(a, tar, 0, tar->entry_bytes_remaining)
552		    != ARCHIVE_OK)
553			return (ARCHIVE_FATAL);
554	} else {
555		struct sparse_block *sb;
556
557		for (sb = tar->sparse_list; sb != NULL; sb = sb->next) {
558			if (!sb->hole)
559				archive_entry_sparse_add_entry(entry,
560				    sb->offset, sb->remaining);
561		}
562	}
563
564	if (r == ARCHIVE_OK && archive_entry_filetype(entry) == AE_IFREG) {
565		/*
566		 * "Regular" entry with trailing '/' is really
567		 * directory: This is needed for certain old tar
568		 * variants and even for some broken newer ones.
569		 */
570		if ((wp = archive_entry_pathname_w(entry)) != NULL) {
571			l = wcslen(wp);
572			if (l > 0 && wp[l - 1] == L'/') {
573				archive_entry_set_filetype(entry, AE_IFDIR);
574				tar->entry_bytes_remaining = 0;
575				tar->entry_padding = 0;
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				tar->entry_bytes_remaining = 0;
582				tar->entry_padding = 0;
583			}
584		}
585	}
586	return (r);
587}
588
589static int
590archive_read_format_tar_read_data(struct archive_read *a,
591    const void **buff, size_t *size, int64_t *offset)
592{
593	ssize_t bytes_read;
594	struct tar *tar;
595	struct sparse_block *p;
596
597	tar = (struct tar *)(a->format->data);
598
599	for (;;) {
600		/* Remove exhausted entries from sparse list. */
601		while (tar->sparse_list != NULL &&
602		    tar->sparse_list->remaining == 0) {
603			p = tar->sparse_list;
604			tar->sparse_list = p->next;
605			free(p);
606		}
607
608		if (tar->entry_bytes_unconsumed) {
609			__archive_read_consume(a, tar->entry_bytes_unconsumed);
610			tar->entry_bytes_unconsumed = 0;
611		}
612
613		/* If we're at end of file, return EOF. */
614		if (tar->sparse_list == NULL ||
615		    tar->entry_bytes_remaining == 0) {
616			if (__archive_read_consume(a, tar->entry_padding) < 0)
617				return (ARCHIVE_FATAL);
618			tar->entry_padding = 0;
619			*buff = NULL;
620			*size = 0;
621			*offset = tar->realsize;
622			return (ARCHIVE_EOF);
623		}
624
625		*buff = __archive_read_ahead(a, 1, &bytes_read);
626		if (bytes_read < 0)
627			return (ARCHIVE_FATAL);
628		if (*buff == NULL) {
629			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
630			    "Truncated tar archive");
631			return (ARCHIVE_FATAL);
632		}
633		if (bytes_read > tar->entry_bytes_remaining)
634			bytes_read = (ssize_t)tar->entry_bytes_remaining;
635		/* Don't read more than is available in the
636		 * current sparse block. */
637		if (tar->sparse_list->remaining < bytes_read)
638			bytes_read = (ssize_t)tar->sparse_list->remaining;
639		*size = bytes_read;
640		*offset = tar->sparse_list->offset;
641		tar->sparse_list->remaining -= bytes_read;
642		tar->sparse_list->offset += bytes_read;
643		tar->entry_bytes_remaining -= bytes_read;
644		tar->entry_bytes_unconsumed = bytes_read;
645
646		if (!tar->sparse_list->hole)
647			return (ARCHIVE_OK);
648		/* Current is hole data and skip this. */
649	}
650}
651
652static int
653archive_read_format_tar_skip(struct archive_read *a)
654{
655	int64_t bytes_skipped;
656	int64_t request;
657	struct sparse_block *p;
658	struct tar* tar;
659
660	tar = (struct tar *)(a->format->data);
661
662	/* Do not consume the hole of a sparse file. */
663	request = 0;
664	for (p = tar->sparse_list; p != NULL; p = p->next) {
665		if (!p->hole) {
666			if (p->remaining >= INT64_MAX - request) {
667				return ARCHIVE_FATAL;
668			}
669			request += p->remaining;
670		}
671	}
672	if (request > tar->entry_bytes_remaining)
673		request = tar->entry_bytes_remaining;
674	request += tar->entry_padding + tar->entry_bytes_unconsumed;
675
676	bytes_skipped = __archive_read_consume(a, request);
677	if (bytes_skipped < 0)
678		return (ARCHIVE_FATAL);
679
680	tar->entry_bytes_remaining = 0;
681	tar->entry_bytes_unconsumed = 0;
682	tar->entry_padding = 0;
683
684	/* Free the sparse list. */
685	gnu_clear_sparse_list(tar);
686
687	return (ARCHIVE_OK);
688}
689
690/*
691 * This function recursively interprets all of the headers associated
692 * with a single entry.
693 */
694static int
695tar_read_header(struct archive_read *a, struct tar *tar,
696    struct archive_entry *entry, size_t *unconsumed)
697{
698	ssize_t bytes;
699	int err, eof_vol_header;
700	const char *h;
701	const struct archive_entry_header_ustar *header;
702	const struct archive_entry_header_gnutar *gnuheader;
703
704	eof_vol_header = 0;
705
706	/* Loop until we find a workable header record. */
707	for (;;) {
708		tar_flush_unconsumed(a, unconsumed);
709
710		/* Read 512-byte header record */
711		h = __archive_read_ahead(a, 512, &bytes);
712		if (bytes < 0)
713			return ((int)bytes);
714		if (bytes == 0) { /* EOF at a block boundary. */
715			/* Some writers do omit the block of nulls. <sigh> */
716			return (ARCHIVE_EOF);
717		}
718		if (bytes < 512) {  /* Short block at EOF; this is bad. */
719			archive_set_error(&a->archive,
720			    ARCHIVE_ERRNO_FILE_FORMAT,
721			    "Truncated tar archive");
722			return (ARCHIVE_FATAL);
723		}
724		*unconsumed = 512;
725
726		/* Header is workable if it's not an end-of-archive mark. */
727		if (h[0] != 0 || !archive_block_is_null(h))
728			break;
729
730		/* Ensure format is set for archives with only null blocks. */
731		if (a->archive.archive_format_name == NULL) {
732			a->archive.archive_format = ARCHIVE_FORMAT_TAR;
733			a->archive.archive_format_name = "tar";
734		}
735
736		if (!tar->read_concatenated_archives) {
737			/* Try to consume a second all-null record, as well. */
738			tar_flush_unconsumed(a, unconsumed);
739			h = __archive_read_ahead(a, 512, NULL);
740			if (h != NULL && h[0] == 0 && archive_block_is_null(h))
741				__archive_read_consume(a, 512);
742			archive_clear_error(&a->archive);
743			return (ARCHIVE_EOF);
744		}
745
746		/*
747		 * We're reading concatenated archives, ignore this block and
748		 * loop to get the next.
749		 */
750	}
751
752	/*
753	 * Note: If the checksum fails and we return ARCHIVE_RETRY,
754	 * then the client is likely to just retry.  This is a very
755	 * crude way to search for the next valid header!
756	 *
757	 * TODO: Improve this by implementing a real header scan.
758	 */
759	if (!checksum(a, h)) {
760		tar_flush_unconsumed(a, unconsumed);
761		archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
762		return (ARCHIVE_RETRY); /* Retryable: Invalid header */
763	}
764
765	if (++tar->header_recursion_depth > 32) {
766		tar_flush_unconsumed(a, unconsumed);
767		archive_set_error(&a->archive, EINVAL, "Too many special headers");
768		return (ARCHIVE_WARN);
769	}
770
771	/* Determine the format variant. */
772	header = (const struct archive_entry_header_ustar *)h;
773
774	switch(header->typeflag[0]) {
775	case 'A': /* Solaris tar ACL */
776		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
777		a->archive.archive_format_name = "Solaris tar";
778		err = header_Solaris_ACL(a, tar, entry, h, unconsumed);
779		break;
780	case 'g': /* POSIX-standard 'g' header. */
781		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
782		a->archive.archive_format_name = "POSIX pax interchange format";
783		err = header_pax_global(a, tar, entry, h, unconsumed);
784		if (err == ARCHIVE_EOF)
785			return (err);
786		break;
787	case 'K': /* Long link name (GNU tar, others) */
788		err = header_longlink(a, tar, entry, h, unconsumed);
789		break;
790	case 'L': /* Long filename (GNU tar, others) */
791		err = header_longname(a, tar, entry, h, unconsumed);
792		break;
793	case 'V': /* GNU volume header */
794		err = header_volume(a, tar, entry, h, unconsumed);
795		if (err == ARCHIVE_EOF)
796			eof_vol_header = 1;
797		break;
798	case 'X': /* Used by SUN tar; same as 'x'. */
799		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
800		a->archive.archive_format_name =
801		    "POSIX pax interchange format (Sun variant)";
802		err = header_pax_extensions(a, tar, entry, h, unconsumed);
803		break;
804	case 'x': /* POSIX-standard 'x' header. */
805		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
806		a->archive.archive_format_name = "POSIX pax interchange format";
807		err = header_pax_extensions(a, tar, entry, h, unconsumed);
808		break;
809	default:
810		gnuheader = (const struct archive_entry_header_gnutar *)h;
811		if (memcmp(gnuheader->magic, "ustar  \0", 8) == 0) {
812			a->archive.archive_format = ARCHIVE_FORMAT_TAR_GNUTAR;
813			a->archive.archive_format_name = "GNU tar format";
814			err = header_gnutar(a, tar, entry, h, unconsumed);
815		} else if (memcmp(header->magic, "ustar", 5) == 0) {
816			if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
817				a->archive.archive_format = ARCHIVE_FORMAT_TAR_USTAR;
818				a->archive.archive_format_name = "POSIX ustar format";
819			}
820			err = header_ustar(a, tar, entry, h);
821		} else {
822			a->archive.archive_format = ARCHIVE_FORMAT_TAR;
823			a->archive.archive_format_name = "tar (non-POSIX)";
824			err = header_old_tar(a, tar, entry, h);
825		}
826	}
827	if (err == ARCHIVE_FATAL)
828		return (err);
829
830	tar_flush_unconsumed(a, unconsumed);
831
832	h = NULL;
833	header = NULL;
834
835	--tar->header_recursion_depth;
836	/* Yuck.  Apple's design here ends up storing long pathname
837	 * extensions for both the AppleDouble extension entry and the
838	 * regular entry.
839	 */
840	if ((err == ARCHIVE_WARN || err == ARCHIVE_OK) &&
841	    tar->header_recursion_depth == 0 &&
842	    tar->process_mac_extensions) {
843		int err2 = read_mac_metadata_blob(a, tar, entry, h, unconsumed);
844		if (err2 < err)
845			err = err2;
846	}
847
848	/* We return warnings or success as-is.  Anything else is fatal. */
849	if (err == ARCHIVE_WARN || err == ARCHIVE_OK) {
850		if (tar->sparse_gnu_pending) {
851			if (tar->sparse_gnu_major == 1 &&
852			    tar->sparse_gnu_minor == 0) {
853				ssize_t bytes_read;
854
855				tar->sparse_gnu_pending = 0;
856				/* Read initial sparse map. */
857				bytes_read = gnu_sparse_10_read(a, tar, unconsumed);
858				if (bytes_read < 0)
859					return ((int)bytes_read);
860				tar->entry_bytes_remaining -= bytes_read;
861			} else {
862				archive_set_error(&a->archive,
863				    ARCHIVE_ERRNO_MISC,
864				    "Unrecognized GNU sparse file format");
865				return (ARCHIVE_WARN);
866			}
867			tar->sparse_gnu_pending = 0;
868		}
869		return (err);
870	}
871	if (err == ARCHIVE_EOF) {
872		if (!eof_vol_header) {
873			/* EOF when recursively reading a header is bad. */
874			archive_set_error(&a->archive, EINVAL,
875			    "Damaged tar archive");
876		} else {
877			/* If we encounter just a GNU volume header treat
878			 * this situation as an empty archive */
879			return (ARCHIVE_EOF);
880		}
881	}
882	return (ARCHIVE_FATAL);
883}
884
885/*
886 * Return true if block checksum is correct.
887 */
888static int
889checksum(struct archive_read *a, const void *h)
890{
891	const unsigned char *bytes;
892	const struct archive_entry_header_ustar	*header;
893	int check, sum;
894	size_t i;
895
896	(void)a; /* UNUSED */
897	bytes = (const unsigned char *)h;
898	header = (const struct archive_entry_header_ustar *)h;
899
900	/* Checksum field must hold an octal number */
901	for (i = 0; i < sizeof(header->checksum); ++i) {
902		char c = header->checksum[i];
903		if (c != ' ' && c != '\0' && (c < '0' || c > '7'))
904			return 0;
905	}
906
907	/*
908	 * Test the checksum.  Note that POSIX specifies _unsigned_
909	 * bytes for this calculation.
910	 */
911	sum = (int)tar_atol(header->checksum, sizeof(header->checksum));
912	check = 0;
913	for (i = 0; i < 148; i++)
914		check += (unsigned char)bytes[i];
915	for (; i < 156; i++)
916		check += 32;
917	for (; i < 512; i++)
918		check += (unsigned char)bytes[i];
919	if (sum == check)
920		return (1);
921
922	/*
923	 * Repeat test with _signed_ bytes, just in case this archive
924	 * was created by an old BSD, Solaris, or HP-UX tar with a
925	 * broken checksum calculation.
926	 */
927	check = 0;
928	for (i = 0; i < 148; i++)
929		check += (signed char)bytes[i];
930	for (; i < 156; i++)
931		check += 32;
932	for (; i < 512; i++)
933		check += (signed char)bytes[i];
934	if (sum == check)
935		return (1);
936
937	return (0);
938}
939
940/*
941 * Return true if this block contains only nulls.
942 */
943static int
944archive_block_is_null(const char *p)
945{
946	unsigned i;
947
948	for (i = 0; i < 512; i++)
949		if (*p++)
950			return (0);
951	return (1);
952}
953
954/*
955 * Interpret 'A' Solaris ACL header
956 */
957static int
958header_Solaris_ACL(struct archive_read *a, struct tar *tar,
959    struct archive_entry *entry, const void *h, size_t *unconsumed)
960{
961	const struct archive_entry_header_ustar *header;
962	size_t size;
963	int err, acl_type;
964	int64_t type;
965	char *acl, *p;
966
967	/*
968	 * read_body_to_string adds a NUL terminator, but we need a little
969	 * more to make sure that we don't overrun acl_text later.
970	 */
971	header = (const struct archive_entry_header_ustar *)h;
972	size = (size_t)tar_atol(header->size, sizeof(header->size));
973	err = read_body_to_string(a, tar, &(tar->acl_text), h, unconsumed);
974	if (err != ARCHIVE_OK)
975		return (err);
976
977	/* Recursively read next header */
978	err = tar_read_header(a, tar, entry, unconsumed);
979	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
980		return (err);
981
982	/* TODO: Examine the first characters to see if this
983	 * is an AIX ACL descriptor.  We'll likely never support
984	 * them, but it would be polite to recognize and warn when
985	 * we do see them. */
986
987	/* Leading octal number indicates ACL type and number of entries. */
988	p = acl = tar->acl_text.s;
989	type = 0;
990	while (*p != '\0' && p < acl + size) {
991		if (*p < '0' || *p > '7') {
992			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
993			    "Malformed Solaris ACL attribute (invalid digit)");
994			return(ARCHIVE_WARN);
995		}
996		type <<= 3;
997		type += *p - '0';
998		if (type > 077777777) {
999			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1000			    "Malformed Solaris ACL attribute (count too large)");
1001			return (ARCHIVE_WARN);
1002		}
1003		p++;
1004	}
1005	switch ((int)type & ~0777777) {
1006	case 01000000:
1007		/* POSIX.1e ACL */
1008		acl_type = ARCHIVE_ENTRY_ACL_TYPE_ACCESS;
1009		break;
1010	case 03000000:
1011		/* NFSv4 ACL */
1012		acl_type = ARCHIVE_ENTRY_ACL_TYPE_NFS4;
1013		break;
1014	default:
1015		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1016		    "Malformed Solaris ACL attribute (unsupported type %o)",
1017		    (int)type);
1018		return (ARCHIVE_WARN);
1019	}
1020	p++;
1021
1022	if (p >= acl + size) {
1023		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1024		    "Malformed Solaris ACL attribute (body overflow)");
1025		return(ARCHIVE_WARN);
1026	}
1027
1028	/* ACL text is null-terminated; find the end. */
1029	size -= (p - acl);
1030	acl = p;
1031
1032	while (*p != '\0' && p < acl + size)
1033		p++;
1034
1035	if (tar->sconv_acl == NULL) {
1036		tar->sconv_acl = archive_string_conversion_from_charset(
1037		    &(a->archive), "UTF-8", 1);
1038		if (tar->sconv_acl == NULL)
1039			return (ARCHIVE_FATAL);
1040	}
1041	archive_strncpy(&(tar->localname), acl, p - acl);
1042	err = archive_acl_from_text_l(archive_entry_acl(entry),
1043	    tar->localname.s, acl_type, tar->sconv_acl);
1044	if (err != ARCHIVE_OK) {
1045		if (errno == ENOMEM) {
1046			archive_set_error(&a->archive, ENOMEM,
1047			    "Can't allocate memory for ACL");
1048		} else
1049			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1050			    "Malformed Solaris ACL attribute (unparsable)");
1051	}
1052	return (err);
1053}
1054
1055/*
1056 * Interpret 'K' long linkname header.
1057 */
1058static int
1059header_longlink(struct archive_read *a, struct tar *tar,
1060    struct archive_entry *entry, const void *h, size_t *unconsumed)
1061{
1062	int err;
1063
1064	err = read_body_to_string(a, tar, &(tar->longlink), h, unconsumed);
1065	if (err != ARCHIVE_OK)
1066		return (err);
1067	err = tar_read_header(a, tar, entry, unconsumed);
1068	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1069		return (err);
1070	/* Set symlink if symlink already set, else hardlink. */
1071	archive_entry_copy_link(entry, tar->longlink.s);
1072	return (ARCHIVE_OK);
1073}
1074
1075static int
1076set_conversion_failed_error(struct archive_read *a,
1077    struct archive_string_conv *sconv, const char *name)
1078{
1079	if (errno == ENOMEM) {
1080		archive_set_error(&a->archive, ENOMEM,
1081		    "Can't allocate memory for %s", name);
1082		return (ARCHIVE_FATAL);
1083	}
1084	archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
1085	    "%s can't be converted from %s to current locale.",
1086	    name, archive_string_conversion_charset_name(sconv));
1087	return (ARCHIVE_WARN);
1088}
1089
1090/*
1091 * Interpret 'L' long filename header.
1092 */
1093static int
1094header_longname(struct archive_read *a, struct tar *tar,
1095    struct archive_entry *entry, const void *h, size_t *unconsumed)
1096{
1097	int err;
1098
1099	err = read_body_to_string(a, tar, &(tar->longname), h, unconsumed);
1100	if (err != ARCHIVE_OK)
1101		return (err);
1102	/* Read and parse "real" header, then override name. */
1103	err = tar_read_header(a, tar, entry, unconsumed);
1104	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1105		return (err);
1106	if (archive_entry_copy_pathname_l(entry, tar->longname.s,
1107	    archive_strlen(&(tar->longname)), tar->sconv) != 0)
1108		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1109	return (err);
1110}
1111
1112
1113/*
1114 * Interpret 'V' GNU tar volume header.
1115 */
1116static int
1117header_volume(struct archive_read *a, struct tar *tar,
1118    struct archive_entry *entry, const void *h, size_t *unconsumed)
1119{
1120	(void)h;
1121
1122	/* Just skip this and read the next header. */
1123	return (tar_read_header(a, tar, entry, unconsumed));
1124}
1125
1126/*
1127 * Read body of an archive entry into an archive_string object.
1128 */
1129static int
1130read_body_to_string(struct archive_read *a, struct tar *tar,
1131    struct archive_string *as, const void *h, size_t *unconsumed)
1132{
1133	int64_t size;
1134	const struct archive_entry_header_ustar *header;
1135	const void *src;
1136
1137	(void)tar; /* UNUSED */
1138	header = (const struct archive_entry_header_ustar *)h;
1139	size  = tar_atol(header->size, sizeof(header->size));
1140	if ((size > 1048576) || (size < 0)) {
1141		archive_set_error(&a->archive, EINVAL,
1142		    "Special header too large");
1143		return (ARCHIVE_FATAL);
1144	}
1145
1146	/* Fail if we can't make our buffer big enough. */
1147	if (archive_string_ensure(as, (size_t)size+1) == NULL) {
1148		archive_set_error(&a->archive, ENOMEM,
1149		    "No memory");
1150		return (ARCHIVE_FATAL);
1151	}
1152
1153	tar_flush_unconsumed(a, unconsumed);
1154
1155	/* Read the body into the string. */
1156	*unconsumed = (size_t)((size + 511) & ~ 511);
1157	src = __archive_read_ahead(a, *unconsumed, NULL);
1158	if (src == NULL) {
1159		*unconsumed = 0;
1160		return (ARCHIVE_FATAL);
1161	}
1162	memcpy(as->s, src, (size_t)size);
1163	as->s[size] = '\0';
1164	as->length = (size_t)size;
1165	return (ARCHIVE_OK);
1166}
1167
1168/*
1169 * Parse out common header elements.
1170 *
1171 * This would be the same as header_old_tar, except that the
1172 * filename is handled slightly differently for old and POSIX
1173 * entries  (POSIX entries support a 'prefix').  This factoring
1174 * allows header_old_tar and header_ustar
1175 * to handle filenames differently, while still putting most of the
1176 * common parsing into one place.
1177 */
1178static int
1179header_common(struct archive_read *a, struct tar *tar,
1180    struct archive_entry *entry, const void *h)
1181{
1182	const struct archive_entry_header_ustar	*header;
1183	char	tartype;
1184	int     err = ARCHIVE_OK;
1185
1186	header = (const struct archive_entry_header_ustar *)h;
1187	if (header->linkname[0])
1188		archive_strncpy(&(tar->entry_linkpath),
1189		    header->linkname, sizeof(header->linkname));
1190	else
1191		archive_string_empty(&(tar->entry_linkpath));
1192
1193	/* Parse out the numeric fields (all are octal) */
1194	archive_entry_set_mode(entry,
1195		(mode_t)tar_atol(header->mode, sizeof(header->mode)));
1196	archive_entry_set_uid(entry, tar_atol(header->uid, sizeof(header->uid)));
1197	archive_entry_set_gid(entry, tar_atol(header->gid, sizeof(header->gid)));
1198	tar->entry_bytes_remaining = tar_atol(header->size, sizeof(header->size));
1199	if (tar->entry_bytes_remaining < 0) {
1200		tar->entry_bytes_remaining = 0;
1201		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1202		    "Tar entry has negative size");
1203		return (ARCHIVE_FATAL);
1204	}
1205	if (tar->entry_bytes_remaining == INT64_MAX) {
1206		/* Note: tar_atol returns INT64_MAX on overflow */
1207		tar->entry_bytes_remaining = 0;
1208		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1209		    "Tar entry size overflow");
1210		return (ARCHIVE_FATAL);
1211	}
1212	tar->realsize = tar->entry_bytes_remaining;
1213	archive_entry_set_size(entry, tar->entry_bytes_remaining);
1214	archive_entry_set_mtime(entry, tar_atol(header->mtime, sizeof(header->mtime)), 0);
1215
1216	/* Handle the tar type flag appropriately. */
1217	tartype = header->typeflag[0];
1218
1219	switch (tartype) {
1220	case '1': /* Hard link */
1221		if (archive_entry_copy_hardlink_l(entry, tar->entry_linkpath.s,
1222		    archive_strlen(&(tar->entry_linkpath)), tar->sconv) != 0) {
1223			err = set_conversion_failed_error(a, tar->sconv,
1224			    "Linkname");
1225			if (err == ARCHIVE_FATAL)
1226				return (err);
1227		}
1228		/*
1229		 * The following may seem odd, but: Technically, tar
1230		 * does not store the file type for a "hard link"
1231		 * entry, only the fact that it is a hard link.  So, I
1232		 * leave the type zero normally.  But, pax interchange
1233		 * format allows hard links to have data, which
1234		 * implies that the underlying entry is a regular
1235		 * file.
1236		 */
1237		if (archive_entry_size(entry) > 0)
1238			archive_entry_set_filetype(entry, AE_IFREG);
1239
1240		/*
1241		 * A tricky point: Traditionally, tar readers have
1242		 * ignored the size field when reading hardlink
1243		 * entries, and some writers put non-zero sizes even
1244		 * though the body is empty.  POSIX blessed this
1245		 * convention in the 1988 standard, but broke with
1246		 * this tradition in 2001 by permitting hardlink
1247		 * entries to store valid bodies in pax interchange
1248		 * format, but not in ustar format.  Since there is no
1249		 * hard and fast way to distinguish pax interchange
1250		 * from earlier archives (the 'x' and 'g' entries are
1251		 * optional, after all), we need a heuristic.
1252		 */
1253		if (archive_entry_size(entry) == 0) {
1254			/* If the size is already zero, we're done. */
1255		}  else if (a->archive.archive_format
1256		    == ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
1257			/* Definitely pax extended; must obey hardlink size. */
1258		} else if (a->archive.archive_format == ARCHIVE_FORMAT_TAR
1259		    || a->archive.archive_format == ARCHIVE_FORMAT_TAR_GNUTAR)
1260		{
1261			/* Old-style or GNU tar: we must ignore the size. */
1262			archive_entry_set_size(entry, 0);
1263			tar->entry_bytes_remaining = 0;
1264		} else if (archive_read_format_tar_bid(a, 50) > 50) {
1265			/*
1266			 * We don't know if it's pax: If the bid
1267			 * function sees a valid ustar header
1268			 * immediately following, then let's ignore
1269			 * the hardlink size.
1270			 */
1271			archive_entry_set_size(entry, 0);
1272			tar->entry_bytes_remaining = 0;
1273		}
1274		/*
1275		 * TODO: There are still two cases I'd like to handle:
1276		 *   = a ustar non-pax archive with a hardlink entry at
1277		 *     end-of-archive.  (Look for block of nulls following?)
1278		 *   = a pax archive that has not seen any pax headers
1279		 *     and has an entry which is a hardlink entry storing
1280		 *     a body containing an uncompressed tar archive.
1281		 * The first is worth addressing; I don't see any reliable
1282		 * way to deal with the second possibility.
1283		 */
1284		break;
1285	case '2': /* Symlink */
1286		archive_entry_set_filetype(entry, AE_IFLNK);
1287		archive_entry_set_size(entry, 0);
1288		tar->entry_bytes_remaining = 0;
1289		if (archive_entry_copy_symlink_l(entry, tar->entry_linkpath.s,
1290		    archive_strlen(&(tar->entry_linkpath)), tar->sconv) != 0) {
1291			err = set_conversion_failed_error(a, tar->sconv,
1292			    "Linkname");
1293			if (err == ARCHIVE_FATAL)
1294				return (err);
1295		}
1296		break;
1297	case '3': /* Character device */
1298		archive_entry_set_filetype(entry, AE_IFCHR);
1299		archive_entry_set_size(entry, 0);
1300		tar->entry_bytes_remaining = 0;
1301		break;
1302	case '4': /* Block device */
1303		archive_entry_set_filetype(entry, AE_IFBLK);
1304		archive_entry_set_size(entry, 0);
1305		tar->entry_bytes_remaining = 0;
1306		break;
1307	case '5': /* Dir */
1308		archive_entry_set_filetype(entry, AE_IFDIR);
1309		archive_entry_set_size(entry, 0);
1310		tar->entry_bytes_remaining = 0;
1311		break;
1312	case '6': /* FIFO device */
1313		archive_entry_set_filetype(entry, AE_IFIFO);
1314		archive_entry_set_size(entry, 0);
1315		tar->entry_bytes_remaining = 0;
1316		break;
1317	case 'D': /* GNU incremental directory type */
1318		/*
1319		 * No special handling is actually required here.
1320		 * It might be nice someday to preprocess the file list and
1321		 * provide it to the client, though.
1322		 */
1323		archive_entry_set_filetype(entry, AE_IFDIR);
1324		break;
1325	case 'M': /* GNU "Multi-volume" (remainder of file from last archive)*/
1326		/*
1327		 * As far as I can tell, this is just like a regular file
1328		 * entry, except that the contents should be _appended_ to
1329		 * the indicated file at the indicated offset.  This may
1330		 * require some API work to fully support.
1331		 */
1332		break;
1333	case 'N': /* Old GNU "long filename" entry. */
1334		/* The body of this entry is a script for renaming
1335		 * previously-extracted entries.  Ugh.  It will never
1336		 * be supported by libarchive. */
1337		archive_entry_set_filetype(entry, AE_IFREG);
1338		break;
1339	case 'S': /* GNU sparse files */
1340		/*
1341		 * Sparse files are really just regular files with
1342		 * sparse information in the extended area.
1343		 */
1344		/* FALLTHROUGH */
1345	case '0':
1346		/*
1347		 * Enable sparse file "read" support only for regular
1348		 * files and explicit GNU sparse files.  However, we
1349		 * don't allow non-standard file types to be sparse.
1350		 */
1351		tar->sparse_allowed = 1;
1352		/* FALLTHROUGH */
1353	default: /* Regular file  and non-standard types */
1354		/*
1355		 * Per POSIX: non-recognized types should always be
1356		 * treated as regular files.
1357		 */
1358		archive_entry_set_filetype(entry, AE_IFREG);
1359		break;
1360	}
1361	return (err);
1362}
1363
1364/*
1365 * Parse out header elements for "old-style" tar archives.
1366 */
1367static int
1368header_old_tar(struct archive_read *a, struct tar *tar,
1369    struct archive_entry *entry, const void *h)
1370{
1371	const struct archive_entry_header_ustar	*header;
1372	int err = ARCHIVE_OK, err2;
1373
1374	/* Copy filename over (to ensure null termination). */
1375	header = (const struct archive_entry_header_ustar *)h;
1376	if (archive_entry_copy_pathname_l(entry,
1377	    header->name, sizeof(header->name), tar->sconv) != 0) {
1378		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1379		if (err == ARCHIVE_FATAL)
1380			return (err);
1381	}
1382
1383	/* Grab rest of common fields */
1384	err2 = header_common(a, tar, entry, h);
1385	if (err > err2)
1386		err = err2;
1387
1388	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1389	return (err);
1390}
1391
1392/*
1393 * Read a Mac AppleDouble-encoded blob of file metadata,
1394 * if there is one.
1395 */
1396static int
1397read_mac_metadata_blob(struct archive_read *a, struct tar *tar,
1398    struct archive_entry *entry, const void *h, size_t *unconsumed)
1399{
1400	int64_t size;
1401	size_t msize;
1402	const void *data;
1403	const char *p, *name;
1404	const wchar_t *wp, *wname;
1405
1406	(void)h; /* UNUSED */
1407
1408	wname = wp = archive_entry_pathname_w(entry);
1409	if (wp != NULL) {
1410		/* Find the last path element. */
1411		for (; *wp != L'\0'; ++wp) {
1412			if (wp[0] == '/' && wp[1] != L'\0')
1413				wname = wp + 1;
1414		}
1415		/*
1416		 * If last path element starts with "._", then
1417		 * this is a Mac extension.
1418		 */
1419		if (wname[0] != L'.' || wname[1] != L'_' || wname[2] == L'\0')
1420			return ARCHIVE_OK;
1421	} else {
1422		/* Find the last path element. */
1423		name = p = archive_entry_pathname(entry);
1424		if (p == NULL)
1425			return (ARCHIVE_FAILED);
1426		for (; *p != '\0'; ++p) {
1427			if (p[0] == '/' && p[1] != '\0')
1428				name = p + 1;
1429		}
1430		/*
1431		 * If last path element starts with "._", then
1432		 * this is a Mac extension.
1433		 */
1434		if (name[0] != '.' || name[1] != '_' || name[2] == '\0')
1435			return ARCHIVE_OK;
1436	}
1437
1438 	/* Read the body as a Mac OS metadata blob. */
1439	size = archive_entry_size(entry);
1440	msize = (size_t)size;
1441	if (size < 0 || (uintmax_t)msize != (uintmax_t)size) {
1442		*unconsumed = 0;
1443		return (ARCHIVE_FATAL);
1444	}
1445
1446	/*
1447	 * TODO: Look beyond the body here to peek at the next header.
1448	 * If it's a regular header (not an extension header)
1449	 * that has the wrong name, just return the current
1450	 * entry as-is, without consuming the body here.
1451	 * That would reduce the risk of us mis-identifying
1452	 * an ordinary file that just happened to have
1453	 * a name starting with "._".
1454	 *
1455	 * Q: Is the above idea really possible?  Even
1456	 * when there are GNU or pax extension entries?
1457	 */
1458	data = __archive_read_ahead(a, msize, NULL);
1459	if (data == NULL) {
1460		*unconsumed = 0;
1461		return (ARCHIVE_FATAL);
1462	}
1463	archive_entry_copy_mac_metadata(entry, data, msize);
1464	*unconsumed = (msize + 511) & ~ 511;
1465	tar_flush_unconsumed(a, unconsumed);
1466	return (tar_read_header(a, tar, entry, unconsumed));
1467}
1468
1469/*
1470 * Parse a file header for a pax extended archive entry.
1471 */
1472static int
1473header_pax_global(struct archive_read *a, struct tar *tar,
1474    struct archive_entry *entry, const void *h, size_t *unconsumed)
1475{
1476	int err;
1477
1478	err = read_body_to_string(a, tar, &(tar->pax_global), h, unconsumed);
1479	if (err != ARCHIVE_OK)
1480		return (err);
1481	err = tar_read_header(a, tar, entry, unconsumed);
1482	return (err);
1483}
1484
1485static int
1486header_pax_extensions(struct archive_read *a, struct tar *tar,
1487    struct archive_entry *entry, const void *h, size_t *unconsumed)
1488{
1489	int err, err2;
1490
1491	err = read_body_to_string(a, tar, &(tar->pax_header), h, unconsumed);
1492	if (err != ARCHIVE_OK)
1493		return (err);
1494
1495	/* Parse the next header. */
1496	err = tar_read_header(a, tar, entry, unconsumed);
1497	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1498		return (err);
1499
1500	/*
1501	 * TODO: Parse global/default options into 'entry' struct here
1502	 * before handling file-specific options.
1503	 *
1504	 * This design (parse standard header, then overwrite with pax
1505	 * extended attribute data) usually works well, but isn't ideal;
1506	 * it would be better to parse the pax extended attributes first
1507	 * and then skip any fields in the standard header that were
1508	 * defined in the pax header.
1509	 */
1510	err2 = pax_header(a, tar, entry, &tar->pax_header);
1511	err =  err_combine(err, err2);
1512	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1513	return (err);
1514}
1515
1516
1517/*
1518 * Parse a file header for a Posix "ustar" archive entry.  This also
1519 * handles "pax" or "extended ustar" entries.
1520 */
1521static int
1522header_ustar(struct archive_read *a, struct tar *tar,
1523    struct archive_entry *entry, const void *h)
1524{
1525	const struct archive_entry_header_ustar	*header;
1526	struct archive_string *as;
1527	int err = ARCHIVE_OK, r;
1528
1529	header = (const struct archive_entry_header_ustar *)h;
1530
1531	/* Copy name into an internal buffer to ensure null-termination. */
1532	as = &(tar->entry_pathname);
1533	if (header->prefix[0]) {
1534		archive_strncpy(as, header->prefix, sizeof(header->prefix));
1535		if (as->s[archive_strlen(as) - 1] != '/')
1536			archive_strappend_char(as, '/');
1537		archive_strncat(as, header->name, sizeof(header->name));
1538	} else {
1539		archive_strncpy(as, header->name, sizeof(header->name));
1540	}
1541	if (archive_entry_copy_pathname_l(entry, as->s, archive_strlen(as),
1542	    tar->sconv) != 0) {
1543		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1544		if (err == ARCHIVE_FATAL)
1545			return (err);
1546	}
1547
1548	/* Handle rest of common fields. */
1549	r = header_common(a, tar, entry, h);
1550	if (r == ARCHIVE_FATAL)
1551		return (r);
1552	if (r < err)
1553		err = r;
1554
1555	/* Handle POSIX ustar fields. */
1556	if (archive_entry_copy_uname_l(entry,
1557	    header->uname, sizeof(header->uname), tar->sconv) != 0) {
1558		err = set_conversion_failed_error(a, tar->sconv, "Uname");
1559		if (err == ARCHIVE_FATAL)
1560			return (err);
1561	}
1562
1563	if (archive_entry_copy_gname_l(entry,
1564	    header->gname, sizeof(header->gname), tar->sconv) != 0) {
1565		err = set_conversion_failed_error(a, tar->sconv, "Gname");
1566		if (err == ARCHIVE_FATAL)
1567			return (err);
1568	}
1569
1570	/* Parse out device numbers only for char and block specials. */
1571	if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
1572		archive_entry_set_rdevmajor(entry, (dev_t)
1573		    tar_atol(header->rdevmajor, sizeof(header->rdevmajor)));
1574		archive_entry_set_rdevminor(entry, (dev_t)
1575		    tar_atol(header->rdevminor, sizeof(header->rdevminor)));
1576	}
1577
1578	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1579
1580	return (err);
1581}
1582
1583
1584/*
1585 * Parse the pax extended attributes record.
1586 *
1587 * Returns non-zero if there's an error in the data.
1588 */
1589static int
1590pax_header(struct archive_read *a, struct tar *tar,
1591    struct archive_entry *entry, struct archive_string *in_as)
1592{
1593	size_t attr_length, l, line_length, value_length;
1594	char *p;
1595	char *key, *value;
1596	struct archive_string *as;
1597	struct archive_string_conv *sconv;
1598	int err, err2;
1599	char *attr = in_as->s;
1600
1601	attr_length = in_as->length;
1602	tar->pax_hdrcharset_binary = 0;
1603	archive_string_empty(&(tar->entry_gname));
1604	archive_string_empty(&(tar->entry_linkpath));
1605	archive_string_empty(&(tar->entry_pathname));
1606	archive_string_empty(&(tar->entry_pathname_override));
1607	archive_string_empty(&(tar->entry_uname));
1608	err = ARCHIVE_OK;
1609	while (attr_length > 0) {
1610		/* Parse decimal length field at start of line. */
1611		line_length = 0;
1612		l = attr_length;
1613		p = attr; /* Record start of line. */
1614		while (l>0) {
1615			if (*p == ' ') {
1616				p++;
1617				l--;
1618				break;
1619			}
1620			if (*p < '0' || *p > '9') {
1621				archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1622				    "Ignoring malformed pax extended attributes");
1623				return (ARCHIVE_WARN);
1624			}
1625			line_length *= 10;
1626			line_length += *p - '0';
1627			if (line_length > 999999) {
1628				archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1629				    "Rejecting pax extended attribute > 1MB");
1630				return (ARCHIVE_WARN);
1631			}
1632			p++;
1633			l--;
1634		}
1635
1636		/*
1637		 * Parsed length must be no bigger than available data,
1638		 * at least 1, and the last character of the line must
1639		 * be '\n'.
1640		 */
1641		if (line_length > attr_length
1642		    || line_length < 1
1643		    || attr[line_length - 1] != '\n')
1644		{
1645			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1646			    "Ignoring malformed pax extended attribute");
1647			return (ARCHIVE_WARN);
1648		}
1649
1650		/* Null-terminate the line. */
1651		attr[line_length - 1] = '\0';
1652
1653		/* Find end of key and null terminate it. */
1654		key = p;
1655		if (key[0] == '=')
1656			return (-1);
1657		while (*p && *p != '=')
1658			++p;
1659		if (*p == '\0') {
1660			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1661			    "Invalid pax extended attributes");
1662			return (ARCHIVE_WARN);
1663		}
1664		*p = '\0';
1665
1666		value = p + 1;
1667
1668		/* Some values may be binary data */
1669		value_length = attr + line_length - 1 - value;
1670
1671		/* Identify this attribute and set it in the entry. */
1672		err2 = pax_attribute(a, tar, entry, key, value, value_length);
1673		if (err2 == ARCHIVE_FATAL)
1674			return (err2);
1675		err = err_combine(err, err2);
1676
1677		/* Skip to next line */
1678		attr += line_length;
1679		attr_length -= line_length;
1680	}
1681
1682	/*
1683	 * PAX format uses UTF-8 as default charset for its metadata
1684	 * unless hdrcharset=BINARY is present in its header.
1685	 * We apply the charset specified by the hdrcharset option only
1686	 * when the hdrcharset attribute(in PAX header) is BINARY because
1687	 * we respect the charset described in PAX header and BINARY also
1688	 * means that metadata(filename,uname and gname) character-set
1689	 * is unknown.
1690	 */
1691	if (tar->pax_hdrcharset_binary)
1692		sconv = tar->opt_sconv;
1693	else {
1694		sconv = archive_string_conversion_from_charset(
1695		    &(a->archive), "UTF-8", 1);
1696		if (sconv == NULL)
1697			return (ARCHIVE_FATAL);
1698		if (tar->compat_2x)
1699			archive_string_conversion_set_opt(sconv,
1700			    SCONV_SET_OPT_UTF8_LIBARCHIVE2X);
1701	}
1702
1703	if (archive_strlen(&(tar->entry_gname)) > 0) {
1704		if (archive_entry_copy_gname_l(entry, tar->entry_gname.s,
1705		    archive_strlen(&(tar->entry_gname)), sconv) != 0) {
1706			err = set_conversion_failed_error(a, sconv, "Gname");
1707			if (err == ARCHIVE_FATAL)
1708				return (err);
1709			/* Use a converted an original name. */
1710			archive_entry_copy_gname(entry, tar->entry_gname.s);
1711		}
1712	}
1713	if (archive_strlen(&(tar->entry_linkpath)) > 0) {
1714		if (archive_entry_copy_link_l(entry, tar->entry_linkpath.s,
1715		    archive_strlen(&(tar->entry_linkpath)), sconv) != 0) {
1716			err = set_conversion_failed_error(a, sconv, "Linkname");
1717			if (err == ARCHIVE_FATAL)
1718				return (err);
1719			/* Use a converted an original name. */
1720			archive_entry_copy_link(entry, tar->entry_linkpath.s);
1721		}
1722	}
1723	/*
1724	 * Some extensions (such as the GNU sparse file extensions)
1725	 * deliberately store a synthetic name under the regular 'path'
1726	 * attribute and the real file name under a different attribute.
1727	 * Since we're supposed to not care about the order, we
1728	 * have no choice but to store all of the various filenames
1729	 * we find and figure it all out afterwards.  This is the
1730	 * figuring out part.
1731	 */
1732	as = NULL;
1733	if (archive_strlen(&(tar->entry_pathname_override)) > 0)
1734		as = &(tar->entry_pathname_override);
1735	else if (archive_strlen(&(tar->entry_pathname)) > 0)
1736		as = &(tar->entry_pathname);
1737	if (as != NULL) {
1738		if (archive_entry_copy_pathname_l(entry, as->s,
1739		    archive_strlen(as), sconv) != 0) {
1740			err = set_conversion_failed_error(a, sconv, "Pathname");
1741			if (err == ARCHIVE_FATAL)
1742				return (err);
1743			/* Use a converted an original name. */
1744			archive_entry_copy_pathname(entry, as->s);
1745		}
1746	}
1747	if (archive_strlen(&(tar->entry_uname)) > 0) {
1748		if (archive_entry_copy_uname_l(entry, tar->entry_uname.s,
1749		    archive_strlen(&(tar->entry_uname)), sconv) != 0) {
1750			err = set_conversion_failed_error(a, sconv, "Uname");
1751			if (err == ARCHIVE_FATAL)
1752				return (err);
1753			/* Use a converted an original name. */
1754			archive_entry_copy_uname(entry, tar->entry_uname.s);
1755		}
1756	}
1757	return (err);
1758}
1759
1760static int
1761pax_attribute_xattr(struct archive_entry *entry,
1762	const char *name, const char *value)
1763{
1764	char *name_decoded;
1765	void *value_decoded;
1766	size_t value_len;
1767
1768	if (strlen(name) < 18 || (memcmp(name, "LIBARCHIVE.xattr.", 17)) != 0)
1769		return 3;
1770
1771	name += 17;
1772
1773	/* URL-decode name */
1774	name_decoded = url_decode(name);
1775	if (name_decoded == NULL)
1776		return 2;
1777
1778	/* Base-64 decode value */
1779	value_decoded = base64_decode(value, strlen(value), &value_len);
1780	if (value_decoded == NULL) {
1781		free(name_decoded);
1782		return 1;
1783	}
1784
1785	archive_entry_xattr_add_entry(entry, name_decoded,
1786		value_decoded, value_len);
1787
1788	free(name_decoded);
1789	free(value_decoded);
1790	return 0;
1791}
1792
1793static int
1794pax_attribute_schily_xattr(struct archive_entry *entry,
1795	const char *name, const char *value, size_t value_length)
1796{
1797	if (strlen(name) < 14 || (memcmp(name, "SCHILY.xattr.", 13)) != 0)
1798		return 1;
1799
1800	name += 13;
1801
1802	archive_entry_xattr_add_entry(entry, name, value, value_length);
1803
1804	return 0;
1805}
1806
1807static int
1808pax_attribute_rht_security_selinux(struct archive_entry *entry,
1809	const char *value, size_t value_length)
1810{
1811	archive_entry_xattr_add_entry(entry, "security.selinux",
1812            value, value_length);
1813
1814	return 0;
1815}
1816
1817static int
1818pax_attribute_acl(struct archive_read *a, struct tar *tar,
1819    struct archive_entry *entry, const char *value, int type)
1820{
1821	int r;
1822	const char* errstr;
1823
1824	switch (type) {
1825	case ARCHIVE_ENTRY_ACL_TYPE_ACCESS:
1826		errstr = "SCHILY.acl.access";
1827		break;
1828	case ARCHIVE_ENTRY_ACL_TYPE_DEFAULT:
1829		errstr = "SCHILY.acl.default";
1830		break;
1831	case ARCHIVE_ENTRY_ACL_TYPE_NFS4:
1832		errstr = "SCHILY.acl.ace";
1833		break;
1834	default:
1835		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1836		    "Unknown ACL type: %d", type);
1837		return(ARCHIVE_FATAL);
1838	}
1839
1840	if (tar->sconv_acl == NULL) {
1841		tar->sconv_acl =
1842		    archive_string_conversion_from_charset(
1843			&(a->archive), "UTF-8", 1);
1844		if (tar->sconv_acl == NULL)
1845			return (ARCHIVE_FATAL);
1846	}
1847
1848	r = archive_acl_from_text_l(archive_entry_acl(entry), value, type,
1849	    tar->sconv_acl);
1850	if (r != ARCHIVE_OK) {
1851		if (r == ARCHIVE_FATAL) {
1852			archive_set_error(&a->archive, ENOMEM,
1853			    "%s %s", "Can't allocate memory for ",
1854			    errstr);
1855			return (r);
1856		}
1857		archive_set_error(&a->archive,
1858		    ARCHIVE_ERRNO_MISC, "%s %s", "Parse error: ", errstr);
1859	}
1860	return (r);
1861}
1862
1863/*
1864 * Parse a single key=value attribute.  key/value pointers are
1865 * assumed to point into reasonably long-lived storage.
1866 *
1867 * Note that POSIX reserves all-lowercase keywords.  Vendor-specific
1868 * extensions should always have keywords of the form "VENDOR.attribute"
1869 * In particular, it's quite feasible to support many different
1870 * vendor extensions here.  I'm using "LIBARCHIVE" for extensions
1871 * unique to this library.
1872 *
1873 * Investigate other vendor-specific extensions and see if
1874 * any of them look useful.
1875 */
1876static int
1877pax_attribute(struct archive_read *a, struct tar *tar,
1878    struct archive_entry *entry, const char *key, const char *value, size_t value_length)
1879{
1880	int64_t s;
1881	long n;
1882	int err = ARCHIVE_OK, r;
1883
1884#ifndef __FreeBSD__
1885	if (value == NULL)
1886		value = "";	/* Disable compiler warning; do not pass
1887				 * NULL pointer to strlen().  */
1888#endif
1889	switch (key[0]) {
1890	case 'G':
1891		/* Reject GNU.sparse.* headers on non-regular files. */
1892		if (strncmp(key, "GNU.sparse", 10) == 0 &&
1893		    !tar->sparse_allowed) {
1894			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1895			    "Non-regular file cannot be sparse");
1896			return (ARCHIVE_FATAL);
1897		}
1898
1899		/* GNU "0.0" sparse pax format. */
1900		if (strcmp(key, "GNU.sparse.numblocks") == 0) {
1901			tar->sparse_offset = -1;
1902			tar->sparse_numbytes = -1;
1903			tar->sparse_gnu_major = 0;
1904			tar->sparse_gnu_minor = 0;
1905		}
1906		if (strcmp(key, "GNU.sparse.offset") == 0) {
1907			tar->sparse_offset = tar_atol10(value, strlen(value));
1908			if (tar->sparse_numbytes != -1) {
1909				if (gnu_add_sparse_entry(a, tar,
1910				    tar->sparse_offset, tar->sparse_numbytes)
1911				    != ARCHIVE_OK)
1912					return (ARCHIVE_FATAL);
1913				tar->sparse_offset = -1;
1914				tar->sparse_numbytes = -1;
1915			}
1916		}
1917		if (strcmp(key, "GNU.sparse.numbytes") == 0) {
1918			tar->sparse_numbytes = tar_atol10(value, strlen(value));
1919			if (tar->sparse_offset != -1) {
1920				if (gnu_add_sparse_entry(a, tar,
1921				    tar->sparse_offset, tar->sparse_numbytes)
1922				    != ARCHIVE_OK)
1923					return (ARCHIVE_FATAL);
1924				tar->sparse_offset = -1;
1925				tar->sparse_numbytes = -1;
1926			}
1927		}
1928		if (strcmp(key, "GNU.sparse.size") == 0) {
1929			tar->realsize = tar_atol10(value, strlen(value));
1930			archive_entry_set_size(entry, tar->realsize);
1931			tar->realsize_override = 1;
1932		}
1933
1934		/* GNU "0.1" sparse pax format. */
1935		if (strcmp(key, "GNU.sparse.map") == 0) {
1936			tar->sparse_gnu_major = 0;
1937			tar->sparse_gnu_minor = 1;
1938			if (gnu_sparse_01_parse(a, tar, value) != ARCHIVE_OK)
1939				return (ARCHIVE_WARN);
1940		}
1941
1942		/* GNU "1.0" sparse pax format */
1943		if (strcmp(key, "GNU.sparse.major") == 0) {
1944			tar->sparse_gnu_major = (int)tar_atol10(value, strlen(value));
1945			tar->sparse_gnu_pending = 1;
1946		}
1947		if (strcmp(key, "GNU.sparse.minor") == 0) {
1948			tar->sparse_gnu_minor = (int)tar_atol10(value, strlen(value));
1949			tar->sparse_gnu_pending = 1;
1950		}
1951		if (strcmp(key, "GNU.sparse.name") == 0) {
1952			/*
1953			 * The real filename; when storing sparse
1954			 * files, GNU tar puts a synthesized name into
1955			 * the regular 'path' attribute in an attempt
1956			 * to limit confusion. ;-)
1957			 */
1958			archive_strcpy(&(tar->entry_pathname_override), value);
1959		}
1960		if (strcmp(key, "GNU.sparse.realsize") == 0) {
1961			tar->realsize = tar_atol10(value, strlen(value));
1962			archive_entry_set_size(entry, tar->realsize);
1963			tar->realsize_override = 1;
1964		}
1965		break;
1966	case 'L':
1967		/* Our extensions */
1968/* TODO: Handle arbitrary extended attributes... */
1969/*
1970		if (strcmp(key, "LIBARCHIVE.xxxxxxx") == 0)
1971			archive_entry_set_xxxxxx(entry, value);
1972*/
1973		if (strcmp(key, "LIBARCHIVE.creationtime") == 0) {
1974			pax_time(value, &s, &n);
1975			archive_entry_set_birthtime(entry, s, n);
1976		}
1977		if (strcmp(key, "LIBARCHIVE.symlinktype") == 0) {
1978			if (strcmp(value, "file") == 0) {
1979				archive_entry_set_symlink_type(entry,
1980				    AE_SYMLINK_TYPE_FILE);
1981			} else if (strcmp(value, "dir") == 0) {
1982				archive_entry_set_symlink_type(entry,
1983				    AE_SYMLINK_TYPE_DIRECTORY);
1984			}
1985		}
1986		if (memcmp(key, "LIBARCHIVE.xattr.", 17) == 0)
1987			pax_attribute_xattr(entry, key, value);
1988		break;
1989	case 'R':
1990		/* GNU tar uses RHT.security header to store SELinux xattrs
1991		 * SCHILY.xattr.security.selinux == RHT.security.selinux */
1992		if (strcmp(key, "RHT.security.selinux") == 0) {
1993			pax_attribute_rht_security_selinux(entry, value,
1994			    value_length);
1995			}
1996		break;
1997	case 'S':
1998		/* We support some keys used by the "star" archiver */
1999		if (strcmp(key, "SCHILY.acl.access") == 0) {
2000			r = pax_attribute_acl(a, tar, entry, value,
2001			    ARCHIVE_ENTRY_ACL_TYPE_ACCESS);
2002			if (r == ARCHIVE_FATAL)
2003				return (r);
2004		} else if (strcmp(key, "SCHILY.acl.default") == 0) {
2005			r = pax_attribute_acl(a, tar, entry, value,
2006			    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT);
2007			if (r == ARCHIVE_FATAL)
2008				return (r);
2009		} else if (strcmp(key, "SCHILY.acl.ace") == 0) {
2010			r = pax_attribute_acl(a, tar, entry, value,
2011			    ARCHIVE_ENTRY_ACL_TYPE_NFS4);
2012			if (r == ARCHIVE_FATAL)
2013				return (r);
2014		} else if (strcmp(key, "SCHILY.devmajor") == 0) {
2015			archive_entry_set_rdevmajor(entry,
2016			    (dev_t)tar_atol10(value, strlen(value)));
2017		} else if (strcmp(key, "SCHILY.devminor") == 0) {
2018			archive_entry_set_rdevminor(entry,
2019			    (dev_t)tar_atol10(value, strlen(value)));
2020		} else if (strcmp(key, "SCHILY.fflags") == 0) {
2021			archive_entry_copy_fflags_text(entry, value);
2022		} else if (strcmp(key, "SCHILY.dev") == 0) {
2023			archive_entry_set_dev(entry,
2024			    (dev_t)tar_atol10(value, strlen(value)));
2025		} else if (strcmp(key, "SCHILY.ino") == 0) {
2026			archive_entry_set_ino(entry,
2027			    tar_atol10(value, strlen(value)));
2028		} else if (strcmp(key, "SCHILY.nlink") == 0) {
2029			archive_entry_set_nlink(entry, (unsigned)
2030			    tar_atol10(value, strlen(value)));
2031		} else if (strcmp(key, "SCHILY.realsize") == 0) {
2032			tar->realsize = tar_atol10(value, strlen(value));
2033			tar->realsize_override = 1;
2034			archive_entry_set_size(entry, tar->realsize);
2035		} else if (strncmp(key, "SCHILY.xattr.", 13) == 0) {
2036			pax_attribute_schily_xattr(entry, key, value,
2037			    value_length);
2038		} else if (strcmp(key, "SUN.holesdata") == 0) {
2039			/* A Solaris extension for sparse. */
2040			r = solaris_sparse_parse(a, tar, entry, value);
2041			if (r < err) {
2042				if (r == ARCHIVE_FATAL)
2043					return (r);
2044				err = r;
2045				archive_set_error(&a->archive,
2046				    ARCHIVE_ERRNO_MISC,
2047				    "Parse error: SUN.holesdata");
2048			}
2049		}
2050		break;
2051	case 'a':
2052		if (strcmp(key, "atime") == 0) {
2053			pax_time(value, &s, &n);
2054			archive_entry_set_atime(entry, s, n);
2055		}
2056		break;
2057	case 'c':
2058		if (strcmp(key, "ctime") == 0) {
2059			pax_time(value, &s, &n);
2060			archive_entry_set_ctime(entry, s, n);
2061		} else if (strcmp(key, "charset") == 0) {
2062			/* TODO: Publish charset information in entry. */
2063		} else if (strcmp(key, "comment") == 0) {
2064			/* TODO: Publish comment in entry. */
2065		}
2066		break;
2067	case 'g':
2068		if (strcmp(key, "gid") == 0) {
2069			archive_entry_set_gid(entry,
2070			    tar_atol10(value, strlen(value)));
2071		} else if (strcmp(key, "gname") == 0) {
2072			archive_strcpy(&(tar->entry_gname), value);
2073		}
2074		break;
2075	case 'h':
2076		if (strcmp(key, "hdrcharset") == 0) {
2077			if (strcmp(value, "BINARY") == 0)
2078				/* Binary  mode. */
2079				tar->pax_hdrcharset_binary = 1;
2080			else if (strcmp(value, "ISO-IR 10646 2000 UTF-8") == 0)
2081				tar->pax_hdrcharset_binary = 0;
2082		}
2083		break;
2084	case 'l':
2085		/* pax interchange doesn't distinguish hardlink vs. symlink. */
2086		if (strcmp(key, "linkpath") == 0) {
2087			archive_strcpy(&(tar->entry_linkpath), value);
2088		}
2089		break;
2090	case 'm':
2091		if (strcmp(key, "mtime") == 0) {
2092			pax_time(value, &s, &n);
2093			archive_entry_set_mtime(entry, s, n);
2094		}
2095		break;
2096	case 'p':
2097		if (strcmp(key, "path") == 0) {
2098			archive_strcpy(&(tar->entry_pathname), value);
2099		}
2100		break;
2101	case 'r':
2102		/* POSIX has reserved 'realtime.*' */
2103		break;
2104	case 's':
2105		/* POSIX has reserved 'security.*' */
2106		/* Someday: if (strcmp(key, "security.acl") == 0) { ... } */
2107		if (strcmp(key, "size") == 0) {
2108			/* "size" is the size of the data in the entry. */
2109			tar->entry_bytes_remaining
2110			    = tar_atol10(value, strlen(value));
2111			if (tar->entry_bytes_remaining < 0) {
2112				tar->entry_bytes_remaining = 0;
2113				archive_set_error(&a->archive,
2114				    ARCHIVE_ERRNO_MISC,
2115				    "Tar size attribute is negative");
2116				return (ARCHIVE_FATAL);
2117			}
2118			if (tar->entry_bytes_remaining == INT64_MAX) {
2119				/* Note: tar_atol returns INT64_MAX on overflow */
2120				tar->entry_bytes_remaining = 0;
2121				archive_set_error(&a->archive,
2122				    ARCHIVE_ERRNO_MISC,
2123				    "Tar size attribute overflow");
2124				return (ARCHIVE_FATAL);
2125			}
2126			/*
2127			 * The "size" pax header keyword always overrides the
2128			 * "size" field in the tar header.
2129			 * GNU.sparse.realsize, GNU.sparse.size and
2130			 * SCHILY.realsize override this value.
2131			 */
2132			if (!tar->realsize_override) {
2133				archive_entry_set_size(entry,
2134				    tar->entry_bytes_remaining);
2135				tar->realsize
2136				    = tar->entry_bytes_remaining;
2137			}
2138		}
2139		break;
2140	case 'u':
2141		if (strcmp(key, "uid") == 0) {
2142			archive_entry_set_uid(entry,
2143			    tar_atol10(value, strlen(value)));
2144		} else if (strcmp(key, "uname") == 0) {
2145			archive_strcpy(&(tar->entry_uname), value);
2146		}
2147		break;
2148	}
2149	return (err);
2150}
2151
2152
2153
2154/*
2155 * parse a decimal time value, which may include a fractional portion
2156 */
2157static void
2158pax_time(const char *p, int64_t *ps, long *pn)
2159{
2160	char digit;
2161	int64_t	s;
2162	unsigned long l;
2163	int sign;
2164	int64_t limit, last_digit_limit;
2165
2166	limit = INT64_MAX / 10;
2167	last_digit_limit = INT64_MAX % 10;
2168
2169	s = 0;
2170	sign = 1;
2171	if (*p == '-') {
2172		sign = -1;
2173		p++;
2174	}
2175	while (*p >= '0' && *p <= '9') {
2176		digit = *p - '0';
2177		if (s > limit ||
2178		    (s == limit && digit > last_digit_limit)) {
2179			s = INT64_MAX;
2180			break;
2181		}
2182		s = (s * 10) + digit;
2183		++p;
2184	}
2185
2186	*ps = s * sign;
2187
2188	/* Calculate nanoseconds. */
2189	*pn = 0;
2190
2191	if (*p != '.')
2192		return;
2193
2194	l = 100000000UL;
2195	do {
2196		++p;
2197		if (*p >= '0' && *p <= '9')
2198			*pn += (*p - '0') * l;
2199		else
2200			break;
2201	} while (l /= 10);
2202}
2203
2204/*
2205 * Parse GNU tar header
2206 */
2207static int
2208header_gnutar(struct archive_read *a, struct tar *tar,
2209    struct archive_entry *entry, const void *h, size_t *unconsumed)
2210{
2211	const struct archive_entry_header_gnutar *header;
2212	int64_t t;
2213	int err = ARCHIVE_OK;
2214
2215	/*
2216	 * GNU header is like POSIX ustar, except 'prefix' is
2217	 * replaced with some other fields. This also means the
2218	 * filename is stored as in old-style archives.
2219	 */
2220
2221	/* Grab fields common to all tar variants. */
2222	err = header_common(a, tar, entry, h);
2223	if (err == ARCHIVE_FATAL)
2224		return (err);
2225
2226	/* Copy filename over (to ensure null termination). */
2227	header = (const struct archive_entry_header_gnutar *)h;
2228	if (archive_entry_copy_pathname_l(entry,
2229	    header->name, sizeof(header->name), tar->sconv) != 0) {
2230		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
2231		if (err == ARCHIVE_FATAL)
2232			return (err);
2233	}
2234
2235	/* Fields common to ustar and GNU */
2236	/* XXX Can the following be factored out since it's common
2237	 * to ustar and gnu tar?  Is it okay to move it down into
2238	 * header_common, perhaps?  */
2239	if (archive_entry_copy_uname_l(entry,
2240	    header->uname, sizeof(header->uname), tar->sconv) != 0) {
2241		err = set_conversion_failed_error(a, tar->sconv, "Uname");
2242		if (err == ARCHIVE_FATAL)
2243			return (err);
2244	}
2245
2246	if (archive_entry_copy_gname_l(entry,
2247	    header->gname, sizeof(header->gname), tar->sconv) != 0) {
2248		err = set_conversion_failed_error(a, tar->sconv, "Gname");
2249		if (err == ARCHIVE_FATAL)
2250			return (err);
2251	}
2252
2253	/* Parse out device numbers only for char and block specials */
2254	if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
2255		archive_entry_set_rdevmajor(entry, (dev_t)
2256		    tar_atol(header->rdevmajor, sizeof(header->rdevmajor)));
2257		archive_entry_set_rdevminor(entry, (dev_t)
2258		    tar_atol(header->rdevminor, sizeof(header->rdevminor)));
2259	} else
2260		archive_entry_set_rdev(entry, 0);
2261
2262	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
2263
2264	/* Grab GNU-specific fields. */
2265	t = tar_atol(header->atime, sizeof(header->atime));
2266	if (t > 0)
2267		archive_entry_set_atime(entry, t, 0);
2268	t = tar_atol(header->ctime, sizeof(header->ctime));
2269	if (t > 0)
2270		archive_entry_set_ctime(entry, t, 0);
2271
2272	if (header->realsize[0] != 0) {
2273		tar->realsize
2274		    = tar_atol(header->realsize, sizeof(header->realsize));
2275		archive_entry_set_size(entry, tar->realsize);
2276		tar->realsize_override = 1;
2277	}
2278
2279	if (header->sparse[0].offset[0] != 0) {
2280		if (gnu_sparse_old_read(a, tar, header, unconsumed)
2281		    != ARCHIVE_OK)
2282			return (ARCHIVE_FATAL);
2283	} else {
2284		if (header->isextended[0] != 0) {
2285			/* XXX WTF? XXX */
2286		}
2287	}
2288
2289	return (err);
2290}
2291
2292static int
2293gnu_add_sparse_entry(struct archive_read *a, struct tar *tar,
2294    int64_t offset, int64_t remaining)
2295{
2296	struct sparse_block *p;
2297
2298	p = (struct sparse_block *)calloc(1, sizeof(*p));
2299	if (p == NULL) {
2300		archive_set_error(&a->archive, ENOMEM, "Out of memory");
2301		return (ARCHIVE_FATAL);
2302	}
2303	if (tar->sparse_last != NULL)
2304		tar->sparse_last->next = p;
2305	else
2306		tar->sparse_list = p;
2307	tar->sparse_last = p;
2308	if (remaining < 0 || offset < 0 || offset > INT64_MAX - remaining) {
2309		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Malformed sparse map data");
2310		return (ARCHIVE_FATAL);
2311	}
2312	p->offset = offset;
2313	p->remaining = remaining;
2314	return (ARCHIVE_OK);
2315}
2316
2317static void
2318gnu_clear_sparse_list(struct tar *tar)
2319{
2320	struct sparse_block *p;
2321
2322	while (tar->sparse_list != NULL) {
2323		p = tar->sparse_list;
2324		tar->sparse_list = p->next;
2325		free(p);
2326	}
2327	tar->sparse_last = NULL;
2328}
2329
2330/*
2331 * GNU tar old-format sparse data.
2332 *
2333 * GNU old-format sparse data is stored in a fixed-field
2334 * format.  Offset/size values are 11-byte octal fields (same
2335 * format as 'size' field in ustart header).  These are
2336 * stored in the header, allocating subsequent header blocks
2337 * as needed.  Extending the header in this way is a pretty
2338 * severe POSIX violation; this design has earned GNU tar a
2339 * lot of criticism.
2340 */
2341
2342static int
2343gnu_sparse_old_read(struct archive_read *a, struct tar *tar,
2344    const struct archive_entry_header_gnutar *header, size_t *unconsumed)
2345{
2346	ssize_t bytes_read;
2347	const void *data;
2348	struct extended {
2349		struct gnu_sparse sparse[21];
2350		char	isextended[1];
2351		char	padding[7];
2352	};
2353	const struct extended *ext;
2354
2355	if (gnu_sparse_old_parse(a, tar, header->sparse, 4) != ARCHIVE_OK)
2356		return (ARCHIVE_FATAL);
2357	if (header->isextended[0] == 0)
2358		return (ARCHIVE_OK);
2359
2360	do {
2361		tar_flush_unconsumed(a, unconsumed);
2362		data = __archive_read_ahead(a, 512, &bytes_read);
2363		if (bytes_read < 0)
2364			return (ARCHIVE_FATAL);
2365		if (bytes_read < 512) {
2366			archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
2367			    "Truncated tar archive "
2368			    "detected while reading sparse file data");
2369			return (ARCHIVE_FATAL);
2370		}
2371		*unconsumed = 512;
2372		ext = (const struct extended *)data;
2373		if (gnu_sparse_old_parse(a, tar, ext->sparse, 21) != ARCHIVE_OK)
2374			return (ARCHIVE_FATAL);
2375	} while (ext->isextended[0] != 0);
2376	if (tar->sparse_list != NULL)
2377		tar->entry_offset = tar->sparse_list->offset;
2378	return (ARCHIVE_OK);
2379}
2380
2381static int
2382gnu_sparse_old_parse(struct archive_read *a, struct tar *tar,
2383    const struct gnu_sparse *sparse, int length)
2384{
2385	while (length > 0 && sparse->offset[0] != 0) {
2386		if (gnu_add_sparse_entry(a, tar,
2387		    tar_atol(sparse->offset, sizeof(sparse->offset)),
2388		    tar_atol(sparse->numbytes, sizeof(sparse->numbytes)))
2389		    != ARCHIVE_OK)
2390			return (ARCHIVE_FATAL);
2391		sparse++;
2392		length--;
2393	}
2394	return (ARCHIVE_OK);
2395}
2396
2397/*
2398 * GNU tar sparse format 0.0
2399 *
2400 * Beginning with GNU tar 1.15, sparse files are stored using
2401 * information in the pax extended header.  The GNU tar maintainers
2402 * have gone through a number of variations in the process of working
2403 * out this scheme; fortunately, they're all numbered.
2404 *
2405 * Sparse format 0.0 uses attribute GNU.sparse.numblocks to store the
2406 * number of blocks, and GNU.sparse.offset/GNU.sparse.numbytes to
2407 * store offset/size for each block.  The repeated instances of these
2408 * latter fields violate the pax specification (which frowns on
2409 * duplicate keys), so this format was quickly replaced.
2410 */
2411
2412/*
2413 * GNU tar sparse format 0.1
2414 *
2415 * This version replaced the offset/numbytes attributes with
2416 * a single "map" attribute that stored a list of integers.  This
2417 * format had two problems: First, the "map" attribute could be very
2418 * long, which caused problems for some implementations.  More
2419 * importantly, the sparse data was lost when extracted by archivers
2420 * that didn't recognize this extension.
2421 */
2422
2423static int
2424gnu_sparse_01_parse(struct archive_read *a, struct tar *tar, const char *p)
2425{
2426	const char *e;
2427	int64_t offset = -1, size = -1;
2428
2429	for (;;) {
2430		e = p;
2431		while (*e != '\0' && *e != ',') {
2432			if (*e < '0' || *e > '9')
2433				return (ARCHIVE_WARN);
2434			e++;
2435		}
2436		if (offset < 0) {
2437			offset = tar_atol10(p, e - p);
2438			if (offset < 0)
2439				return (ARCHIVE_WARN);
2440		} else {
2441			size = tar_atol10(p, e - p);
2442			if (size < 0)
2443				return (ARCHIVE_WARN);
2444			if (gnu_add_sparse_entry(a, tar, offset, size)
2445			    != ARCHIVE_OK)
2446				return (ARCHIVE_FATAL);
2447			offset = -1;
2448		}
2449		if (*e == '\0')
2450			return (ARCHIVE_OK);
2451		p = e + 1;
2452	}
2453}
2454
2455/*
2456 * GNU tar sparse format 1.0
2457 *
2458 * The idea: The offset/size data is stored as a series of base-10
2459 * ASCII numbers prepended to the file data, so that dearchivers that
2460 * don't support this format will extract the block map along with the
2461 * data and a separate post-process can restore the sparseness.
2462 *
2463 * Unfortunately, GNU tar 1.16 had a bug that added unnecessary
2464 * padding to the body of the file when using this format.  GNU tar
2465 * 1.17 corrected this bug without bumping the version number, so
2466 * it's not possible to support both variants.  This code supports
2467 * the later variant at the expense of not supporting the former.
2468 *
2469 * This variant also replaced GNU.sparse.size with GNU.sparse.realsize
2470 * and introduced the GNU.sparse.major/GNU.sparse.minor attributes.
2471 */
2472
2473/*
2474 * Read the next line from the input, and parse it as a decimal
2475 * integer followed by '\n'.  Returns positive integer value or
2476 * negative on error.
2477 */
2478static int64_t
2479gnu_sparse_10_atol(struct archive_read *a, struct tar *tar,
2480    int64_t *remaining, size_t *unconsumed)
2481{
2482	int64_t l, limit, last_digit_limit;
2483	const char *p;
2484	ssize_t bytes_read;
2485	int base, digit;
2486
2487	base = 10;
2488	limit = INT64_MAX / base;
2489	last_digit_limit = INT64_MAX % base;
2490
2491	/*
2492	 * Skip any lines starting with '#'; GNU tar specs
2493	 * don't require this, but they should.
2494	 */
2495	do {
2496		bytes_read = readline(a, tar, &p,
2497			(ssize_t)tar_min(*remaining, 100), unconsumed);
2498		if (bytes_read <= 0)
2499			return (ARCHIVE_FATAL);
2500		*remaining -= bytes_read;
2501	} while (p[0] == '#');
2502
2503	l = 0;
2504	while (bytes_read > 0) {
2505		if (*p == '\n')
2506			return (l);
2507		if (*p < '0' || *p >= '0' + base)
2508			return (ARCHIVE_WARN);
2509		digit = *p - '0';
2510		if (l > limit || (l == limit && digit > last_digit_limit))
2511			l = INT64_MAX; /* Truncate on overflow. */
2512		else
2513			l = (l * base) + digit;
2514		p++;
2515		bytes_read--;
2516	}
2517	/* TODO: Error message. */
2518	return (ARCHIVE_WARN);
2519}
2520
2521/*
2522 * Returns length (in bytes) of the sparse data description
2523 * that was read.
2524 */
2525static ssize_t
2526gnu_sparse_10_read(struct archive_read *a, struct tar *tar, size_t *unconsumed)
2527{
2528	ssize_t bytes_read;
2529	int entries;
2530	int64_t offset, size, to_skip, remaining;
2531
2532	/* Clear out the existing sparse list. */
2533	gnu_clear_sparse_list(tar);
2534
2535	remaining = tar->entry_bytes_remaining;
2536
2537	/* Parse entries. */
2538	entries = (int)gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2539	if (entries < 0)
2540		return (ARCHIVE_FATAL);
2541	/* Parse the individual entries. */
2542	while (entries-- > 0) {
2543		/* Parse offset/size */
2544		offset = gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2545		if (offset < 0)
2546			return (ARCHIVE_FATAL);
2547		size = gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2548		if (size < 0)
2549			return (ARCHIVE_FATAL);
2550		/* Add a new sparse entry. */
2551		if (gnu_add_sparse_entry(a, tar, offset, size) != ARCHIVE_OK)
2552			return (ARCHIVE_FATAL);
2553	}
2554	/* Skip rest of block... */
2555	tar_flush_unconsumed(a, unconsumed);
2556	bytes_read = (ssize_t)(tar->entry_bytes_remaining - remaining);
2557	to_skip = 0x1ff & -bytes_read;
2558	/* Fail if tar->entry_bytes_remaing would get negative */
2559	if (to_skip > remaining)
2560		return (ARCHIVE_FATAL);
2561	if (to_skip != __archive_read_consume(a, to_skip))
2562		return (ARCHIVE_FATAL);
2563	return ((ssize_t)(bytes_read + to_skip));
2564}
2565
2566/*
2567 * Solaris pax extension for a sparse file. This is recorded with the
2568 * data and hole pairs. The way recording sparse information by Solaris'
2569 * pax simply indicates where data and sparse are, so the stored contents
2570 * consist of both data and hole.
2571 */
2572static int
2573solaris_sparse_parse(struct archive_read *a, struct tar *tar,
2574    struct archive_entry *entry, const char *p)
2575{
2576	const char *e;
2577	int64_t start, end;
2578	int hole = 1;
2579
2580	(void)entry; /* UNUSED */
2581
2582	end = 0;
2583	if (*p == ' ')
2584		p++;
2585	else
2586		return (ARCHIVE_WARN);
2587	for (;;) {
2588		e = p;
2589		while (*e != '\0' && *e != ' ') {
2590			if (*e < '0' || *e > '9')
2591				return (ARCHIVE_WARN);
2592			e++;
2593		}
2594		start = end;
2595		end = tar_atol10(p, e - p);
2596		if (end < 0)
2597			return (ARCHIVE_WARN);
2598		if (start < end) {
2599			if (gnu_add_sparse_entry(a, tar, start,
2600			    end - start) != ARCHIVE_OK)
2601				return (ARCHIVE_FATAL);
2602			tar->sparse_last->hole = hole;
2603		}
2604		if (*e == '\0')
2605			return (ARCHIVE_OK);
2606		p = e + 1;
2607		hole = hole == 0;
2608	}
2609}
2610
2611/*-
2612 * Convert text->integer.
2613 *
2614 * Traditional tar formats (including POSIX) specify base-8 for
2615 * all of the standard numeric fields.  This is a significant limitation
2616 * in practice:
2617 *   = file size is limited to 8GB
2618 *   = rdevmajor and rdevminor are limited to 21 bits
2619 *   = uid/gid are limited to 21 bits
2620 *
2621 * There are two workarounds for this:
2622 *   = pax extended headers, which use variable-length string fields
2623 *   = GNU tar and STAR both allow either base-8 or base-256 in
2624 *      most fields.  The high bit is set to indicate base-256.
2625 *
2626 * On read, this implementation supports both extensions.
2627 */
2628static int64_t
2629tar_atol(const char *p, size_t char_cnt)
2630{
2631	/*
2632	 * Technically, GNU tar considers a field to be in base-256
2633	 * only if the first byte is 0xff or 0x80.
2634	 */
2635	if (*p & 0x80)
2636		return (tar_atol256(p, char_cnt));
2637	return (tar_atol8(p, char_cnt));
2638}
2639
2640/*
2641 * Note that this implementation does not (and should not!) obey
2642 * locale settings; you cannot simply substitute strtol here, since
2643 * it does obey locale.
2644 */
2645static int64_t
2646tar_atol_base_n(const char *p, size_t char_cnt, int base)
2647{
2648	int64_t	l, maxval, limit, last_digit_limit;
2649	int digit, sign;
2650
2651	maxval = INT64_MAX;
2652	limit = INT64_MAX / base;
2653	last_digit_limit = INT64_MAX % base;
2654
2655	/* the pointer will not be dereferenced if char_cnt is zero
2656	 * due to the way the && operator is evaluated.
2657	 */
2658	while (char_cnt != 0 && (*p == ' ' || *p == '\t')) {
2659		p++;
2660		char_cnt--;
2661	}
2662
2663	sign = 1;
2664	if (char_cnt != 0 && *p == '-') {
2665		sign = -1;
2666		p++;
2667		char_cnt--;
2668
2669		maxval = INT64_MIN;
2670		limit = -(INT64_MIN / base);
2671		last_digit_limit = -(INT64_MIN % base);
2672	}
2673
2674	l = 0;
2675	if (char_cnt != 0) {
2676		digit = *p - '0';
2677		while (digit >= 0 && digit < base  && char_cnt != 0) {
2678			if (l>limit || (l == limit && digit >= last_digit_limit)) {
2679				return maxval; /* Truncate on overflow. */
2680			}
2681			l = (l * base) + digit;
2682			digit = *++p - '0';
2683			char_cnt--;
2684		}
2685	}
2686	return (sign < 0) ? -l : l;
2687}
2688
2689static int64_t
2690tar_atol8(const char *p, size_t char_cnt)
2691{
2692	return tar_atol_base_n(p, char_cnt, 8);
2693}
2694
2695static int64_t
2696tar_atol10(const char *p, size_t char_cnt)
2697{
2698	return tar_atol_base_n(p, char_cnt, 10);
2699}
2700
2701/*
2702 * Parse a base-256 integer.  This is just a variable-length
2703 * twos-complement signed binary value in big-endian order, except
2704 * that the high-order bit is ignored.  The values here can be up to
2705 * 12 bytes, so we need to be careful about overflowing 64-bit
2706 * (8-byte) integers.
2707 *
2708 * This code unashamedly assumes that the local machine uses 8-bit
2709 * bytes and twos-complement arithmetic.
2710 */
2711static int64_t
2712tar_atol256(const char *_p, size_t char_cnt)
2713{
2714	uint64_t l;
2715	const unsigned char *p = (const unsigned char *)_p;
2716	unsigned char c, neg;
2717
2718	/* Extend 7-bit 2s-comp to 8-bit 2s-comp, decide sign. */
2719	c = *p;
2720	if (c & 0x40) {
2721		neg = 0xff;
2722		c |= 0x80;
2723		l = ~ARCHIVE_LITERAL_ULL(0);
2724	} else {
2725		neg = 0;
2726		c &= 0x7f;
2727		l = 0;
2728	}
2729
2730	/* If more than 8 bytes, check that we can ignore
2731	 * high-order bits without overflow. */
2732	while (char_cnt > sizeof(int64_t)) {
2733		--char_cnt;
2734		if (c != neg)
2735			return neg ? INT64_MIN : INT64_MAX;
2736		c = *++p;
2737	}
2738
2739	/* c is first byte that fits; if sign mismatch, return overflow */
2740	if ((c ^ neg) & 0x80) {
2741		return neg ? INT64_MIN : INT64_MAX;
2742	}
2743
2744	/* Accumulate remaining bytes. */
2745	while (--char_cnt > 0) {
2746		l = (l << 8) | c;
2747		c = *++p;
2748	}
2749	l = (l << 8) | c;
2750	/* Return signed twos-complement value. */
2751	return (int64_t)(l);
2752}
2753
2754/*
2755 * Returns length of line (including trailing newline)
2756 * or negative on error.  'start' argument is updated to
2757 * point to first character of line.  This avoids copying
2758 * when possible.
2759 */
2760static ssize_t
2761readline(struct archive_read *a, struct tar *tar, const char **start,
2762    ssize_t limit, size_t *unconsumed)
2763{
2764	ssize_t bytes_read;
2765	ssize_t total_size = 0;
2766	const void *t;
2767	const char *s;
2768	void *p;
2769
2770	tar_flush_unconsumed(a, unconsumed);
2771
2772	t = __archive_read_ahead(a, 1, &bytes_read);
2773	if (bytes_read <= 0)
2774		return (ARCHIVE_FATAL);
2775	s = t;  /* Start of line? */
2776	p = memchr(t, '\n', bytes_read);
2777	/* If we found '\n' in the read buffer, return pointer to that. */
2778	if (p != NULL) {
2779		bytes_read = 1 + ((const char *)p) - s;
2780		if (bytes_read > limit) {
2781			archive_set_error(&a->archive,
2782			    ARCHIVE_ERRNO_FILE_FORMAT,
2783			    "Line too long");
2784			return (ARCHIVE_FATAL);
2785		}
2786		*unconsumed = bytes_read;
2787		*start = s;
2788		return (bytes_read);
2789	}
2790	*unconsumed = bytes_read;
2791	/* Otherwise, we need to accumulate in a line buffer. */
2792	for (;;) {
2793		if (total_size + bytes_read > limit) {
2794			archive_set_error(&a->archive,
2795			    ARCHIVE_ERRNO_FILE_FORMAT,
2796			    "Line too long");
2797			return (ARCHIVE_FATAL);
2798		}
2799		if (archive_string_ensure(&tar->line, total_size + bytes_read) == NULL) {
2800			archive_set_error(&a->archive, ENOMEM,
2801			    "Can't allocate working buffer");
2802			return (ARCHIVE_FATAL);
2803		}
2804		memcpy(tar->line.s + total_size, t, bytes_read);
2805		tar_flush_unconsumed(a, unconsumed);
2806		total_size += bytes_read;
2807		/* If we found '\n', clean up and return. */
2808		if (p != NULL) {
2809			*start = tar->line.s;
2810			return (total_size);
2811		}
2812		/* Read some more. */
2813		t = __archive_read_ahead(a, 1, &bytes_read);
2814		if (bytes_read <= 0)
2815			return (ARCHIVE_FATAL);
2816		s = t;  /* Start of line? */
2817		p = memchr(t, '\n', bytes_read);
2818		/* If we found '\n', trim the read. */
2819		if (p != NULL) {
2820			bytes_read = 1 + ((const char *)p) - s;
2821		}
2822		*unconsumed = bytes_read;
2823	}
2824}
2825
2826/*
2827 * base64_decode - Base64 decode
2828 *
2829 * This accepts most variations of base-64 encoding, including:
2830 *    * with or without line breaks
2831 *    * with or without the final group padded with '=' or '_' characters
2832 * (The most economical Base-64 variant does not pad the last group and
2833 * omits line breaks; RFC1341 used for MIME requires both.)
2834 */
2835static char *
2836base64_decode(const char *s, size_t len, size_t *out_len)
2837{
2838	static const unsigned char digits[64] = {
2839		'A','B','C','D','E','F','G','H','I','J','K','L','M','N',
2840		'O','P','Q','R','S','T','U','V','W','X','Y','Z','a','b',
2841		'c','d','e','f','g','h','i','j','k','l','m','n','o','p',
2842		'q','r','s','t','u','v','w','x','y','z','0','1','2','3',
2843		'4','5','6','7','8','9','+','/' };
2844	static unsigned char decode_table[128];
2845	char *out, *d;
2846	const unsigned char *src = (const unsigned char *)s;
2847
2848	/* If the decode table is not yet initialized, prepare it. */
2849	if (decode_table[digits[1]] != 1) {
2850		unsigned i;
2851		memset(decode_table, 0xff, sizeof(decode_table));
2852		for (i = 0; i < sizeof(digits); i++)
2853			decode_table[digits[i]] = i;
2854	}
2855
2856	/* Allocate enough space to hold the entire output. */
2857	/* Note that we may not use all of this... */
2858	out = (char *)malloc(len - len / 4 + 1);
2859	if (out == NULL) {
2860		*out_len = 0;
2861		return (NULL);
2862	}
2863	d = out;
2864
2865	while (len > 0) {
2866		/* Collect the next group of (up to) four characters. */
2867		int v = 0;
2868		int group_size = 0;
2869		while (group_size < 4 && len > 0) {
2870			/* '=' or '_' padding indicates final group. */
2871			if (*src == '=' || *src == '_') {
2872				len = 0;
2873				break;
2874			}
2875			/* Skip illegal characters (including line breaks) */
2876			if (*src > 127 || *src < 32
2877			    || decode_table[*src] == 0xff) {
2878				len--;
2879				src++;
2880				continue;
2881			}
2882			v <<= 6;
2883			v |= decode_table[*src++];
2884			len --;
2885			group_size++;
2886		}
2887		/* Align a short group properly. */
2888		v <<= 6 * (4 - group_size);
2889		/* Unpack the group we just collected. */
2890		switch (group_size) {
2891		case 4: d[2] = v & 0xff;
2892			/* FALLTHROUGH */
2893		case 3: d[1] = (v >> 8) & 0xff;
2894			/* FALLTHROUGH */
2895		case 2: d[0] = (v >> 16) & 0xff;
2896			break;
2897		case 1: /* this is invalid! */
2898			break;
2899		}
2900		d += group_size * 3 / 4;
2901	}
2902
2903	*out_len = d - out;
2904	return (out);
2905}
2906
2907static char *
2908url_decode(const char *in)
2909{
2910	char *out, *d;
2911	const char *s;
2912
2913	out = (char *)malloc(strlen(in) + 1);
2914	if (out == NULL)
2915		return (NULL);
2916	for (s = in, d = out; *s != '\0'; ) {
2917		if (s[0] == '%' && s[1] != '\0' && s[2] != '\0') {
2918			/* Try to convert % escape */
2919			int digit1 = tohex(s[1]);
2920			int digit2 = tohex(s[2]);
2921			if (digit1 >= 0 && digit2 >= 0) {
2922				/* Looks good, consume three chars */
2923				s += 3;
2924				/* Convert output */
2925				*d++ = ((digit1 << 4) | digit2);
2926				continue;
2927			}
2928			/* Else fall through and treat '%' as normal char */
2929		}
2930		*d++ = *s++;
2931	}
2932	*d = '\0';
2933	return (out);
2934}
2935
2936static int
2937tohex(int c)
2938{
2939	if (c >= '0' && c <= '9')
2940		return (c - '0');
2941	else if (c >= 'A' && c <= 'F')
2942		return (c - 'A' + 10);
2943	else if (c >= 'a' && c <= 'f')
2944		return (c - 'a' + 10);
2945	else
2946		return (-1);
2947}
2948