archive_read_support_format_tar.c revision 305192
1/*-
2 * Copyright (c) 2003-2007 Tim Kientzle
3 * Copyright (c) 2011-2012 Michihiro NAKAJIMA
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "archive_platform.h"
28__FBSDID("$FreeBSD: stable/10/contrib/libarchive/libarchive/archive_read_support_format_tar.c 305192 2016-09-01 12:01:23Z mm $");
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	struct sparse_block	*sparse_list;
140	struct sparse_block	*sparse_last;
141	int64_t			 sparse_offset;
142	int64_t			 sparse_numbytes;
143	int			 sparse_gnu_major;
144	int			 sparse_gnu_minor;
145	char			 sparse_gnu_pending;
146
147	struct archive_string	 localname;
148	struct archive_string_conv *opt_sconv;
149	struct archive_string_conv *sconv;
150	struct archive_string_conv *sconv_acl;
151	struct archive_string_conv *sconv_default;
152	int			 init_default_conversion;
153	int			 compat_2x;
154	int			 process_mac_extensions;
155	int			 read_concatenated_archives;
156};
157
158static int	archive_block_is_null(const char *p);
159static char	*base64_decode(const char *, size_t, size_t *);
160static int	gnu_add_sparse_entry(struct archive_read *, struct tar *,
161		    int64_t offset, int64_t remaining);
162
163static void	gnu_clear_sparse_list(struct tar *);
164static int	gnu_sparse_old_read(struct archive_read *, struct tar *,
165		    const struct archive_entry_header_gnutar *header, size_t *);
166static int	gnu_sparse_old_parse(struct archive_read *, struct tar *,
167		    const struct gnu_sparse *sparse, int length);
168static int	gnu_sparse_01_parse(struct archive_read *, struct tar *,
169		    const char *);
170static ssize_t	gnu_sparse_10_read(struct archive_read *, struct tar *,
171			size_t *);
172static int	header_Solaris_ACL(struct archive_read *,  struct tar *,
173		    struct archive_entry *, const void *, size_t *);
174static int	header_common(struct archive_read *,  struct tar *,
175		    struct archive_entry *, const void *);
176static int	header_old_tar(struct archive_read *, struct tar *,
177		    struct archive_entry *, const void *);
178static int	header_pax_extensions(struct archive_read *, struct tar *,
179		    struct archive_entry *, const void *, size_t *);
180static int	header_pax_global(struct archive_read *, struct tar *,
181		    struct archive_entry *, const void *h, size_t *);
182static int	header_longlink(struct archive_read *, struct tar *,
183		    struct archive_entry *, const void *h, size_t *);
184static int	header_longname(struct archive_read *, struct tar *,
185		    struct archive_entry *, const void *h, size_t *);
186static int	read_mac_metadata_blob(struct archive_read *, struct tar *,
187		    struct archive_entry *, const void *h, size_t *);
188static int	header_volume(struct archive_read *, struct tar *,
189		    struct archive_entry *, const void *h, size_t *);
190static int	header_ustar(struct archive_read *, struct tar *,
191		    struct archive_entry *, const void *h);
192static int	header_gnutar(struct archive_read *, struct tar *,
193		    struct archive_entry *, const void *h, size_t *);
194static int	archive_read_format_tar_bid(struct archive_read *, int);
195static int	archive_read_format_tar_options(struct archive_read *,
196		    const char *, const char *);
197static int	archive_read_format_tar_cleanup(struct archive_read *);
198static int	archive_read_format_tar_read_data(struct archive_read *a,
199		    const void **buff, size_t *size, int64_t *offset);
200static int	archive_read_format_tar_skip(struct archive_read *a);
201static int	archive_read_format_tar_read_header(struct archive_read *,
202		    struct archive_entry *);
203static int	checksum(struct archive_read *, const void *);
204static int 	pax_attribute(struct archive_read *, struct tar *,
205		    struct archive_entry *, const char *key, const char *value);
206static int 	pax_header(struct archive_read *, struct tar *,
207		    struct archive_entry *, char *attr);
208static void	pax_time(const char *, int64_t *sec, long *nanos);
209static ssize_t	readline(struct archive_read *, struct tar *, const char **,
210		    ssize_t limit, size_t *);
211static int	read_body_to_string(struct archive_read *, struct tar *,
212		    struct archive_string *, const void *h, size_t *);
213static int	solaris_sparse_parse(struct archive_read *, struct tar *,
214		    struct archive_entry *, const char *);
215static int64_t	tar_atol(const char *, size_t);
216static int64_t	tar_atol10(const char *, size_t);
217static int64_t	tar_atol256(const char *, size_t);
218static int64_t	tar_atol8(const char *, size_t);
219static int	tar_read_header(struct archive_read *, struct tar *,
220		    struct archive_entry *, size_t *);
221static int	tohex(int c);
222static char	*url_decode(const char *);
223static void	tar_flush_unconsumed(struct archive_read *, size_t *);
224
225
226int
227archive_read_support_format_gnutar(struct archive *a)
228{
229	archive_check_magic(a, ARCHIVE_READ_MAGIC,
230	    ARCHIVE_STATE_NEW, "archive_read_support_format_gnutar");
231	return (archive_read_support_format_tar(a));
232}
233
234
235int
236archive_read_support_format_tar(struct archive *_a)
237{
238	struct archive_read *a = (struct archive_read *)_a;
239	struct tar *tar;
240	int r;
241
242	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
243	    ARCHIVE_STATE_NEW, "archive_read_support_format_tar");
244
245	tar = (struct tar *)calloc(1, sizeof(*tar));
246#ifdef HAVE_COPYFILE_H
247	/* Set this by default on Mac OS. */
248	tar->process_mac_extensions = 1;
249#endif
250	if (tar == NULL) {
251		archive_set_error(&a->archive, ENOMEM,
252		    "Can't allocate tar data");
253		return (ARCHIVE_FATAL);
254	}
255
256	r = __archive_read_register_format(a, tar, "tar",
257	    archive_read_format_tar_bid,
258	    archive_read_format_tar_options,
259	    archive_read_format_tar_read_header,
260	    archive_read_format_tar_read_data,
261	    archive_read_format_tar_skip,
262	    NULL,
263	    archive_read_format_tar_cleanup,
264	    NULL,
265	    NULL);
266
267	if (r != ARCHIVE_OK)
268		free(tar);
269	return (ARCHIVE_OK);
270}
271
272static int
273archive_read_format_tar_cleanup(struct archive_read *a)
274{
275	struct tar *tar;
276
277	tar = (struct tar *)(a->format->data);
278	gnu_clear_sparse_list(tar);
279	archive_string_free(&tar->acl_text);
280	archive_string_free(&tar->entry_pathname);
281	archive_string_free(&tar->entry_pathname_override);
282	archive_string_free(&tar->entry_linkpath);
283	archive_string_free(&tar->entry_uname);
284	archive_string_free(&tar->entry_gname);
285	archive_string_free(&tar->line);
286	archive_string_free(&tar->pax_global);
287	archive_string_free(&tar->pax_header);
288	archive_string_free(&tar->longname);
289	archive_string_free(&tar->longlink);
290	archive_string_free(&tar->localname);
291	free(tar);
292	(a->format->data) = NULL;
293	return (ARCHIVE_OK);
294}
295
296
297static int
298archive_read_format_tar_bid(struct archive_read *a, int best_bid)
299{
300	int bid;
301	const char *h;
302	const struct archive_entry_header_ustar *header;
303
304	(void)best_bid; /* UNUSED */
305
306	bid = 0;
307
308	/* Now let's look at the actual header and see if it matches. */
309	h = __archive_read_ahead(a, 512, NULL);
310	if (h == NULL)
311		return (-1);
312
313	/* If it's an end-of-archive mark, we can handle it. */
314	if (h[0] == 0 && archive_block_is_null(h)) {
315		/*
316		 * Usually, I bid the number of bits verified, but
317		 * in this case, 4096 seems excessive so I picked 10 as
318		 * an arbitrary but reasonable-seeming value.
319		 */
320		return (10);
321	}
322
323	/* If it's not an end-of-archive mark, it must have a valid checksum.*/
324	if (!checksum(a, h))
325		return (0);
326	bid += 48;  /* Checksum is usually 6 octal digits. */
327
328	header = (const struct archive_entry_header_ustar *)h;
329
330	/* Recognize POSIX formats. */
331	if ((memcmp(header->magic, "ustar\0", 6) == 0)
332	    && (memcmp(header->version, "00", 2) == 0))
333		bid += 56;
334
335	/* Recognize GNU tar format. */
336	if ((memcmp(header->magic, "ustar ", 6) == 0)
337	    && (memcmp(header->version, " \0", 2) == 0))
338		bid += 56;
339
340	/* Type flag must be null, digit or A-Z, a-z. */
341	if (header->typeflag[0] != 0 &&
342	    !( header->typeflag[0] >= '0' && header->typeflag[0] <= '9') &&
343	    !( header->typeflag[0] >= 'A' && header->typeflag[0] <= 'Z') &&
344	    !( header->typeflag[0] >= 'a' && header->typeflag[0] <= 'z') )
345		return (0);
346	bid += 2;  /* 6 bits of variation in an 8-bit field leaves 2 bits. */
347
348	/* Sanity check: Look at first byte of mode field. */
349	switch (255 & (unsigned)header->mode[0]) {
350	case 0: case 255:
351		/* Base-256 value: No further verification possible! */
352		break;
353	case ' ': /* Not recommended, but not illegal, either. */
354		break;
355	case '0': case '1': case '2': case '3':
356	case '4': case '5': case '6': case '7':
357		/* Octal Value. */
358		/* TODO: Check format of remainder of this field. */
359		break;
360	default:
361		/* Not a valid mode; bail out here. */
362		return (0);
363	}
364	/* TODO: Sanity test uid/gid/size/mtime/rdevmajor/rdevminor fields. */
365
366	return (bid);
367}
368
369static int
370archive_read_format_tar_options(struct archive_read *a,
371    const char *key, const char *val)
372{
373	struct tar *tar;
374	int ret = ARCHIVE_FAILED;
375
376	tar = (struct tar *)(a->format->data);
377	if (strcmp(key, "compat-2x")  == 0) {
378		/* Handle UTF-8 filnames as libarchive 2.x */
379		tar->compat_2x = (val != NULL && val[0] != 0);
380		tar->init_default_conversion = tar->compat_2x;
381		return (ARCHIVE_OK);
382	} else if (strcmp(key, "hdrcharset")  == 0) {
383		if (val == NULL || val[0] == 0)
384			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
385			    "tar: hdrcharset option needs a character-set name");
386		else {
387			tar->opt_sconv =
388			    archive_string_conversion_from_charset(
389				&a->archive, val, 0);
390			if (tar->opt_sconv != NULL)
391				ret = ARCHIVE_OK;
392			else
393				ret = ARCHIVE_FATAL;
394		}
395		return (ret);
396	} else if (strcmp(key, "mac-ext") == 0) {
397		tar->process_mac_extensions = (val != NULL && val[0] != 0);
398		return (ARCHIVE_OK);
399	} else if (strcmp(key, "read_concatenated_archives") == 0) {
400		tar->read_concatenated_archives = (val != NULL && val[0] != 0);
401		return (ARCHIVE_OK);
402	}
403
404	/* Note: The "warn" return is just to inform the options
405	 * supervisor that we didn't handle it.  It will generate
406	 * a suitable error if no one used this option. */
407	return (ARCHIVE_WARN);
408}
409
410/* utility function- this exists to centralize the logic of tracking
411 * how much unconsumed data we have floating around, and to consume
412 * anything outstanding since we're going to do read_aheads
413 */
414static void
415tar_flush_unconsumed(struct archive_read *a, size_t *unconsumed)
416{
417	if (*unconsumed) {
418/*
419		void *data = (void *)__archive_read_ahead(a, *unconsumed, NULL);
420		 * this block of code is to poison claimed unconsumed space, ensuring
421		 * things break if it is in use still.
422		 * currently it WILL break things, so enable it only for debugging this issue
423		if (data) {
424			memset(data, 0xff, *unconsumed);
425		}
426*/
427		__archive_read_consume(a, *unconsumed);
428		*unconsumed = 0;
429	}
430}
431
432/*
433 * The function invoked by archive_read_next_header().  This
434 * just sets up a few things and then calls the internal
435 * tar_read_header() function below.
436 */
437static int
438archive_read_format_tar_read_header(struct archive_read *a,
439    struct archive_entry *entry)
440{
441	/*
442	 * When converting tar archives to cpio archives, it is
443	 * essential that each distinct file have a distinct inode
444	 * number.  To simplify this, we keep a static count here to
445	 * assign fake dev/inode numbers to each tar entry.  Note that
446	 * pax format archives may overwrite this with something more
447	 * useful.
448	 *
449	 * Ideally, we would track every file read from the archive so
450	 * that we could assign the same dev/ino pair to hardlinks,
451	 * but the memory required to store a complete lookup table is
452	 * probably not worthwhile just to support the relatively
453	 * obscure tar->cpio conversion case.
454	 */
455	static int default_inode;
456	static int default_dev;
457	struct tar *tar;
458	const char *p;
459	const wchar_t *wp;
460	int r;
461	size_t l, unconsumed = 0;
462
463	/* Assign default device/inode values. */
464	archive_entry_set_dev(entry, 1 + default_dev); /* Don't use zero. */
465	archive_entry_set_ino(entry, ++default_inode); /* Don't use zero. */
466	/* Limit generated st_ino number to 16 bits. */
467	if (default_inode >= 0xffff) {
468		++default_dev;
469		default_inode = 0;
470	}
471
472	tar = (struct tar *)(a->format->data);
473	tar->entry_offset = 0;
474	gnu_clear_sparse_list(tar);
475	tar->realsize = -1; /* Mark this as "unset" */
476
477	/* Setup default string conversion. */
478	tar->sconv = tar->opt_sconv;
479	if (tar->sconv == NULL) {
480		if (!tar->init_default_conversion) {
481			tar->sconv_default =
482			    archive_string_default_conversion_for_read(&(a->archive));
483			tar->init_default_conversion = 1;
484		}
485		tar->sconv = tar->sconv_default;
486	}
487
488	r = tar_read_header(a, tar, entry, &unconsumed);
489
490	tar_flush_unconsumed(a, &unconsumed);
491
492	/*
493	 * "non-sparse" files are really just sparse files with
494	 * a single block.
495	 */
496	if (tar->sparse_list == NULL) {
497		if (gnu_add_sparse_entry(a, tar, 0, tar->entry_bytes_remaining)
498		    != ARCHIVE_OK)
499			return (ARCHIVE_FATAL);
500	} else {
501		struct sparse_block *sb;
502
503		for (sb = tar->sparse_list; sb != NULL; sb = sb->next) {
504			if (!sb->hole)
505				archive_entry_sparse_add_entry(entry,
506				    sb->offset, sb->remaining);
507		}
508	}
509
510	if (r == ARCHIVE_OK && archive_entry_filetype(entry) == AE_IFREG) {
511		/*
512		 * "Regular" entry with trailing '/' is really
513		 * directory: This is needed for certain old tar
514		 * variants and even for some broken newer ones.
515		 */
516		if ((wp = archive_entry_pathname_w(entry)) != NULL) {
517			l = wcslen(wp);
518			if (l > 0 && wp[l - 1] == L'/') {
519				archive_entry_set_filetype(entry, AE_IFDIR);
520			}
521		} else if ((p = archive_entry_pathname(entry)) != NULL) {
522			l = strlen(p);
523			if (l > 0 && p[l - 1] == '/') {
524				archive_entry_set_filetype(entry, AE_IFDIR);
525			}
526		}
527	}
528	return (r);
529}
530
531static int
532archive_read_format_tar_read_data(struct archive_read *a,
533    const void **buff, size_t *size, int64_t *offset)
534{
535	ssize_t bytes_read;
536	struct tar *tar;
537	struct sparse_block *p;
538
539	tar = (struct tar *)(a->format->data);
540
541	for (;;) {
542		/* Remove exhausted entries from sparse list. */
543		while (tar->sparse_list != NULL &&
544		    tar->sparse_list->remaining == 0) {
545			p = tar->sparse_list;
546			tar->sparse_list = p->next;
547			free(p);
548		}
549
550		if (tar->entry_bytes_unconsumed) {
551			__archive_read_consume(a, tar->entry_bytes_unconsumed);
552			tar->entry_bytes_unconsumed = 0;
553		}
554
555		/* If we're at end of file, return EOF. */
556		if (tar->sparse_list == NULL ||
557		    tar->entry_bytes_remaining == 0) {
558			if (__archive_read_consume(a, tar->entry_padding) < 0)
559				return (ARCHIVE_FATAL);
560			tar->entry_padding = 0;
561			*buff = NULL;
562			*size = 0;
563			*offset = tar->realsize;
564			return (ARCHIVE_EOF);
565		}
566
567		*buff = __archive_read_ahead(a, 1, &bytes_read);
568		if (bytes_read < 0)
569			return (ARCHIVE_FATAL);
570		if (*buff == NULL) {
571			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
572			    "Truncated tar archive");
573			return (ARCHIVE_FATAL);
574		}
575		if (bytes_read > tar->entry_bytes_remaining)
576			bytes_read = (ssize_t)tar->entry_bytes_remaining;
577		/* Don't read more than is available in the
578		 * current sparse block. */
579		if (tar->sparse_list->remaining < bytes_read)
580			bytes_read = (ssize_t)tar->sparse_list->remaining;
581		*size = bytes_read;
582		*offset = tar->sparse_list->offset;
583		tar->sparse_list->remaining -= bytes_read;
584		tar->sparse_list->offset += bytes_read;
585		tar->entry_bytes_remaining -= bytes_read;
586		tar->entry_bytes_unconsumed = bytes_read;
587
588		if (!tar->sparse_list->hole)
589			return (ARCHIVE_OK);
590		/* Current is hole data and skip this. */
591	}
592}
593
594static int
595archive_read_format_tar_skip(struct archive_read *a)
596{
597	int64_t bytes_skipped;
598	int64_t request;
599	struct sparse_block *p;
600	struct tar* tar;
601
602	tar = (struct tar *)(a->format->data);
603
604	/* Do not consume the hole of a sparse file. */
605	request = 0;
606	for (p = tar->sparse_list; p != NULL; p = p->next) {
607		if (!p->hole) {
608			if (p->remaining >= INT64_MAX - request) {
609				return ARCHIVE_FATAL;
610			}
611			request += p->remaining;
612		}
613	}
614	if (request > tar->entry_bytes_remaining)
615		request = tar->entry_bytes_remaining;
616	request += tar->entry_padding + tar->entry_bytes_unconsumed;
617
618	bytes_skipped = __archive_read_consume(a, request);
619	if (bytes_skipped < 0)
620		return (ARCHIVE_FATAL);
621
622	tar->entry_bytes_remaining = 0;
623	tar->entry_bytes_unconsumed = 0;
624	tar->entry_padding = 0;
625
626	/* Free the sparse list. */
627	gnu_clear_sparse_list(tar);
628
629	return (ARCHIVE_OK);
630}
631
632/*
633 * This function recursively interprets all of the headers associated
634 * with a single entry.
635 */
636static int
637tar_read_header(struct archive_read *a, struct tar *tar,
638    struct archive_entry *entry, size_t *unconsumed)
639{
640	ssize_t bytes;
641	int err;
642	const char *h;
643	const struct archive_entry_header_ustar *header;
644	const struct archive_entry_header_gnutar *gnuheader;
645
646	/* Loop until we find a workable header record. */
647	for (;;) {
648		tar_flush_unconsumed(a, unconsumed);
649
650		/* Read 512-byte header record */
651		h = __archive_read_ahead(a, 512, &bytes);
652		if (bytes < 0)
653			return ((int)bytes);
654		if (bytes == 0) { /* EOF at a block boundary. */
655			/* Some writers do omit the block of nulls. <sigh> */
656			return (ARCHIVE_EOF);
657		}
658		if (bytes < 512) {  /* Short block at EOF; this is bad. */
659			archive_set_error(&a->archive,
660			    ARCHIVE_ERRNO_FILE_FORMAT,
661			    "Truncated tar archive");
662			return (ARCHIVE_FATAL);
663		}
664		*unconsumed = 512;
665
666		/* Header is workable if it's not an end-of-archive mark. */
667		if (h[0] != 0 || !archive_block_is_null(h))
668			break;
669
670		/* Ensure format is set for archives with only null blocks. */
671		if (a->archive.archive_format_name == NULL) {
672			a->archive.archive_format = ARCHIVE_FORMAT_TAR;
673			a->archive.archive_format_name = "tar";
674		}
675
676		if (!tar->read_concatenated_archives) {
677			/* Try to consume a second all-null record, as well. */
678			tar_flush_unconsumed(a, unconsumed);
679			h = __archive_read_ahead(a, 512, NULL);
680			if (h != NULL && h[0] == 0 && archive_block_is_null(h))
681				__archive_read_consume(a, 512);
682			archive_clear_error(&a->archive);
683			return (ARCHIVE_EOF);
684		}
685
686		/*
687		 * We're reading concatenated archives, ignore this block and
688		 * loop to get the next.
689		 */
690	}
691
692	/*
693	 * Note: If the checksum fails and we return ARCHIVE_RETRY,
694	 * then the client is likely to just retry.  This is a very
695	 * crude way to search for the next valid header!
696	 *
697	 * TODO: Improve this by implementing a real header scan.
698	 */
699	if (!checksum(a, h)) {
700		tar_flush_unconsumed(a, unconsumed);
701		archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
702		return (ARCHIVE_RETRY); /* Retryable: Invalid header */
703	}
704
705	if (++tar->header_recursion_depth > 32) {
706		tar_flush_unconsumed(a, unconsumed);
707		archive_set_error(&a->archive, EINVAL, "Too many special headers");
708		return (ARCHIVE_WARN);
709	}
710
711	/* Determine the format variant. */
712	header = (const struct archive_entry_header_ustar *)h;
713
714	switch(header->typeflag[0]) {
715	case 'A': /* Solaris tar ACL */
716		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
717		a->archive.archive_format_name = "Solaris tar";
718		err = header_Solaris_ACL(a, tar, entry, h, unconsumed);
719		break;
720	case 'g': /* POSIX-standard 'g' header. */
721		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
722		a->archive.archive_format_name = "POSIX pax interchange format";
723		err = header_pax_global(a, tar, entry, h, unconsumed);
724		if (err == ARCHIVE_EOF)
725			return (err);
726		break;
727	case 'K': /* Long link name (GNU tar, others) */
728		err = header_longlink(a, tar, entry, h, unconsumed);
729		break;
730	case 'L': /* Long filename (GNU tar, others) */
731		err = header_longname(a, tar, entry, h, unconsumed);
732		break;
733	case 'V': /* GNU volume header */
734		err = header_volume(a, tar, entry, h, unconsumed);
735		break;
736	case 'X': /* Used by SUN tar; same as 'x'. */
737		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
738		a->archive.archive_format_name =
739		    "POSIX pax interchange format (Sun variant)";
740		err = header_pax_extensions(a, tar, entry, h, unconsumed);
741		break;
742	case 'x': /* POSIX-standard 'x' header. */
743		a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
744		a->archive.archive_format_name = "POSIX pax interchange format";
745		err = header_pax_extensions(a, tar, entry, h, unconsumed);
746		break;
747	default:
748		gnuheader = (const struct archive_entry_header_gnutar *)h;
749		if (memcmp(gnuheader->magic, "ustar  \0", 8) == 0) {
750			a->archive.archive_format = ARCHIVE_FORMAT_TAR_GNUTAR;
751			a->archive.archive_format_name = "GNU tar format";
752			err = header_gnutar(a, tar, entry, h, unconsumed);
753		} else if (memcmp(header->magic, "ustar", 5) == 0) {
754			if (a->archive.archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
755				a->archive.archive_format = ARCHIVE_FORMAT_TAR_USTAR;
756				a->archive.archive_format_name = "POSIX ustar format";
757			}
758			err = header_ustar(a, tar, entry, h);
759		} else {
760			a->archive.archive_format = ARCHIVE_FORMAT_TAR;
761			a->archive.archive_format_name = "tar (non-POSIX)";
762			err = header_old_tar(a, tar, entry, h);
763		}
764	}
765	if (err == ARCHIVE_FATAL)
766		return (err);
767
768	tar_flush_unconsumed(a, unconsumed);
769
770	h = NULL;
771	header = NULL;
772
773	--tar->header_recursion_depth;
774	/* Yuck.  Apple's design here ends up storing long pathname
775	 * extensions for both the AppleDouble extension entry and the
776	 * regular entry.
777	 */
778	if ((err == ARCHIVE_WARN || err == ARCHIVE_OK) &&
779	    tar->header_recursion_depth == 0 &&
780	    tar->process_mac_extensions) {
781		int err2 = read_mac_metadata_blob(a, tar, entry, h, unconsumed);
782		if (err2 < err)
783			err = err2;
784	}
785
786	/* We return warnings or success as-is.  Anything else is fatal. */
787	if (err == ARCHIVE_WARN || err == ARCHIVE_OK) {
788		if (tar->sparse_gnu_pending) {
789			if (tar->sparse_gnu_major == 1 &&
790			    tar->sparse_gnu_minor == 0) {
791				ssize_t bytes_read;
792
793				tar->sparse_gnu_pending = 0;
794				/* Read initial sparse map. */
795				bytes_read = gnu_sparse_10_read(a, tar, unconsumed);
796				tar->entry_bytes_remaining -= bytes_read;
797				if (bytes_read < 0)
798					return ((int)bytes_read);
799			} else {
800				archive_set_error(&a->archive,
801				    ARCHIVE_ERRNO_MISC,
802				    "Unrecognized GNU sparse file format");
803				return (ARCHIVE_WARN);
804			}
805			tar->sparse_gnu_pending = 0;
806		}
807		return (err);
808	}
809	if (err == ARCHIVE_EOF)
810		/* EOF when recursively reading a header is bad. */
811		archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
812	return (ARCHIVE_FATAL);
813}
814
815/*
816 * Return true if block checksum is correct.
817 */
818static int
819checksum(struct archive_read *a, const void *h)
820{
821	const unsigned char *bytes;
822	const struct archive_entry_header_ustar	*header;
823	int check, sum;
824	size_t i;
825
826	(void)a; /* UNUSED */
827	bytes = (const unsigned char *)h;
828	header = (const struct archive_entry_header_ustar *)h;
829
830	/* Checksum field must hold an octal number */
831	for (i = 0; i < sizeof(header->checksum); ++i) {
832		char c = header->checksum[i];
833		if (c != ' ' && c != '\0' && (c < '0' || c > '7'))
834			return 0;
835	}
836
837	/*
838	 * Test the checksum.  Note that POSIX specifies _unsigned_
839	 * bytes for this calculation.
840	 */
841	sum = (int)tar_atol(header->checksum, sizeof(header->checksum));
842	check = 0;
843	for (i = 0; i < 148; i++)
844		check += (unsigned char)bytes[i];
845	for (; i < 156; i++)
846		check += 32;
847	for (; i < 512; i++)
848		check += (unsigned char)bytes[i];
849	if (sum == check)
850		return (1);
851
852	/*
853	 * Repeat test with _signed_ bytes, just in case this archive
854	 * was created by an old BSD, Solaris, or HP-UX tar with a
855	 * broken checksum calculation.
856	 */
857	check = 0;
858	for (i = 0; i < 148; i++)
859		check += (signed char)bytes[i];
860	for (; i < 156; i++)
861		check += 32;
862	for (; i < 512; i++)
863		check += (signed char)bytes[i];
864	if (sum == check)
865		return (1);
866
867	return (0);
868}
869
870/*
871 * Return true if this block contains only nulls.
872 */
873static int
874archive_block_is_null(const char *p)
875{
876	unsigned i;
877
878	for (i = 0; i < 512; i++)
879		if (*p++)
880			return (0);
881	return (1);
882}
883
884/*
885 * Interpret 'A' Solaris ACL header
886 */
887static int
888header_Solaris_ACL(struct archive_read *a, struct tar *tar,
889    struct archive_entry *entry, const void *h, size_t *unconsumed)
890{
891	const struct archive_entry_header_ustar *header;
892	size_t size;
893	int err;
894	int64_t type;
895	char *acl, *p;
896
897	/*
898	 * read_body_to_string adds a NUL terminator, but we need a little
899	 * more to make sure that we don't overrun acl_text later.
900	 */
901	header = (const struct archive_entry_header_ustar *)h;
902	size = (size_t)tar_atol(header->size, sizeof(header->size));
903	err = read_body_to_string(a, tar, &(tar->acl_text), h, unconsumed);
904	if (err != ARCHIVE_OK)
905		return (err);
906
907	/* Recursively read next header */
908	err = tar_read_header(a, tar, entry, unconsumed);
909	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
910		return (err);
911
912	/* TODO: Examine the first characters to see if this
913	 * is an AIX ACL descriptor.  We'll likely never support
914	 * them, but it would be polite to recognize and warn when
915	 * we do see them. */
916
917	/* Leading octal number indicates ACL type and number of entries. */
918	p = acl = tar->acl_text.s;
919	type = 0;
920	while (*p != '\0' && p < acl + size) {
921		if (*p < '0' || *p > '7') {
922			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
923			    "Malformed Solaris ACL attribute (invalid digit)");
924			return(ARCHIVE_WARN);
925		}
926		type <<= 3;
927		type += *p - '0';
928		if (type > 077777777) {
929			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
930			    "Malformed Solaris ACL attribute (count too large)");
931			return (ARCHIVE_WARN);
932		}
933		p++;
934	}
935	switch ((int)type & ~0777777) {
936	case 01000000:
937		/* POSIX.1e ACL */
938		break;
939	case 03000000:
940		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
941		    "Solaris NFSv4 ACLs not supported");
942		return (ARCHIVE_WARN);
943	default:
944		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
945		    "Malformed Solaris ACL attribute (unsupported type %o)",
946		    (int)type);
947		return (ARCHIVE_WARN);
948	}
949	p++;
950
951	if (p >= acl + size) {
952		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
953		    "Malformed Solaris ACL attribute (body overflow)");
954		return(ARCHIVE_WARN);
955	}
956
957	/* ACL text is null-terminated; find the end. */
958	size -= (p - acl);
959	acl = p;
960
961	while (*p != '\0' && p < acl + size)
962		p++;
963
964	if (tar->sconv_acl == NULL) {
965		tar->sconv_acl = archive_string_conversion_from_charset(
966		    &(a->archive), "UTF-8", 1);
967		if (tar->sconv_acl == NULL)
968			return (ARCHIVE_FATAL);
969	}
970	archive_strncpy(&(tar->localname), acl, p - acl);
971	err = archive_acl_parse_l(archive_entry_acl(entry),
972	    tar->localname.s, ARCHIVE_ENTRY_ACL_TYPE_ACCESS, tar->sconv_acl);
973	if (err != ARCHIVE_OK) {
974		if (errno == ENOMEM) {
975			archive_set_error(&a->archive, ENOMEM,
976			    "Can't allocate memory for ACL");
977		} else
978			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
979			    "Malformed Solaris ACL attribute (unparsable)");
980	}
981	return (err);
982}
983
984/*
985 * Interpret 'K' long linkname header.
986 */
987static int
988header_longlink(struct archive_read *a, struct tar *tar,
989    struct archive_entry *entry, const void *h, size_t *unconsumed)
990{
991	int err;
992
993	err = read_body_to_string(a, tar, &(tar->longlink), h, unconsumed);
994	if (err != ARCHIVE_OK)
995		return (err);
996	err = tar_read_header(a, tar, entry, unconsumed);
997	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
998		return (err);
999	/* Set symlink if symlink already set, else hardlink. */
1000	archive_entry_copy_link(entry, tar->longlink.s);
1001	return (ARCHIVE_OK);
1002}
1003
1004static int
1005set_conversion_failed_error(struct archive_read *a,
1006    struct archive_string_conv *sconv, const char *name)
1007{
1008	if (errno == ENOMEM) {
1009		archive_set_error(&a->archive, ENOMEM,
1010		    "Can't allocate memory for %s", name);
1011		return (ARCHIVE_FATAL);
1012	}
1013	archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
1014	    "%s can't be converted from %s to current locale.",
1015	    name, archive_string_conversion_charset_name(sconv));
1016	return (ARCHIVE_WARN);
1017}
1018
1019/*
1020 * Interpret 'L' long filename header.
1021 */
1022static int
1023header_longname(struct archive_read *a, struct tar *tar,
1024    struct archive_entry *entry, const void *h, size_t *unconsumed)
1025{
1026	int err;
1027
1028	err = read_body_to_string(a, tar, &(tar->longname), h, unconsumed);
1029	if (err != ARCHIVE_OK)
1030		return (err);
1031	/* Read and parse "real" header, then override name. */
1032	err = tar_read_header(a, tar, entry, unconsumed);
1033	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1034		return (err);
1035	if (archive_entry_copy_pathname_l(entry, tar->longname.s,
1036	    archive_strlen(&(tar->longname)), tar->sconv) != 0)
1037		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1038	return (err);
1039}
1040
1041
1042/*
1043 * Interpret 'V' GNU tar volume header.
1044 */
1045static int
1046header_volume(struct archive_read *a, struct tar *tar,
1047    struct archive_entry *entry, const void *h, size_t *unconsumed)
1048{
1049	(void)h;
1050
1051	/* Just skip this and read the next header. */
1052	return (tar_read_header(a, tar, entry, unconsumed));
1053}
1054
1055/*
1056 * Read body of an archive entry into an archive_string object.
1057 */
1058static int
1059read_body_to_string(struct archive_read *a, struct tar *tar,
1060    struct archive_string *as, const void *h, size_t *unconsumed)
1061{
1062	int64_t size;
1063	const struct archive_entry_header_ustar *header;
1064	const void *src;
1065
1066	(void)tar; /* UNUSED */
1067	header = (const struct archive_entry_header_ustar *)h;
1068	size  = tar_atol(header->size, sizeof(header->size));
1069	if ((size > 1048576) || (size < 0)) {
1070		archive_set_error(&a->archive, EINVAL,
1071		    "Special header too large");
1072		return (ARCHIVE_FATAL);
1073	}
1074
1075	/* Fail if we can't make our buffer big enough. */
1076	if (archive_string_ensure(as, (size_t)size+1) == NULL) {
1077		archive_set_error(&a->archive, ENOMEM,
1078		    "No memory");
1079		return (ARCHIVE_FATAL);
1080	}
1081
1082	tar_flush_unconsumed(a, unconsumed);
1083
1084	/* Read the body into the string. */
1085	*unconsumed = (size_t)((size + 511) & ~ 511);
1086	src = __archive_read_ahead(a, *unconsumed, NULL);
1087	if (src == NULL) {
1088		*unconsumed = 0;
1089		return (ARCHIVE_FATAL);
1090	}
1091	memcpy(as->s, src, (size_t)size);
1092	as->s[size] = '\0';
1093	as->length = (size_t)size;
1094	return (ARCHIVE_OK);
1095}
1096
1097/*
1098 * Parse out common header elements.
1099 *
1100 * This would be the same as header_old_tar, except that the
1101 * filename is handled slightly differently for old and POSIX
1102 * entries  (POSIX entries support a 'prefix').  This factoring
1103 * allows header_old_tar and header_ustar
1104 * to handle filenames differently, while still putting most of the
1105 * common parsing into one place.
1106 */
1107static int
1108header_common(struct archive_read *a, struct tar *tar,
1109    struct archive_entry *entry, const void *h)
1110{
1111	const struct archive_entry_header_ustar	*header;
1112	char	tartype;
1113	int     err = ARCHIVE_OK;
1114
1115	header = (const struct archive_entry_header_ustar *)h;
1116	if (header->linkname[0])
1117		archive_strncpy(&(tar->entry_linkpath),
1118		    header->linkname, sizeof(header->linkname));
1119	else
1120		archive_string_empty(&(tar->entry_linkpath));
1121
1122	/* Parse out the numeric fields (all are octal) */
1123	archive_entry_set_mode(entry,
1124		(mode_t)tar_atol(header->mode, sizeof(header->mode)));
1125	archive_entry_set_uid(entry, tar_atol(header->uid, sizeof(header->uid)));
1126	archive_entry_set_gid(entry, tar_atol(header->gid, sizeof(header->gid)));
1127	tar->entry_bytes_remaining = tar_atol(header->size, sizeof(header->size));
1128	if (tar->entry_bytes_remaining < 0) {
1129		tar->entry_bytes_remaining = 0;
1130		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1131		    "Tar entry has negative size");
1132		return (ARCHIVE_FATAL);
1133	}
1134	if (tar->entry_bytes_remaining == INT64_MAX) {
1135		/* Note: tar_atol returns INT64_MAX on overflow */
1136		tar->entry_bytes_remaining = 0;
1137		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1138		    "Tar entry size overflow");
1139		return (ARCHIVE_FATAL);
1140	}
1141	tar->realsize = tar->entry_bytes_remaining;
1142	archive_entry_set_size(entry, tar->entry_bytes_remaining);
1143	archive_entry_set_mtime(entry, tar_atol(header->mtime, sizeof(header->mtime)), 0);
1144
1145	/* Handle the tar type flag appropriately. */
1146	tartype = header->typeflag[0];
1147
1148	switch (tartype) {
1149	case '1': /* Hard link */
1150		if (archive_entry_copy_hardlink_l(entry, tar->entry_linkpath.s,
1151		    archive_strlen(&(tar->entry_linkpath)), tar->sconv) != 0) {
1152			err = set_conversion_failed_error(a, tar->sconv,
1153			    "Linkname");
1154			if (err == ARCHIVE_FATAL)
1155				return (err);
1156		}
1157		/*
1158		 * The following may seem odd, but: Technically, tar
1159		 * does not store the file type for a "hard link"
1160		 * entry, only the fact that it is a hard link.  So, I
1161		 * leave the type zero normally.  But, pax interchange
1162		 * format allows hard links to have data, which
1163		 * implies that the underlying entry is a regular
1164		 * file.
1165		 */
1166		if (archive_entry_size(entry) > 0)
1167			archive_entry_set_filetype(entry, AE_IFREG);
1168
1169		/*
1170		 * A tricky point: Traditionally, tar readers have
1171		 * ignored the size field when reading hardlink
1172		 * entries, and some writers put non-zero sizes even
1173		 * though the body is empty.  POSIX blessed this
1174		 * convention in the 1988 standard, but broke with
1175		 * this tradition in 2001 by permitting hardlink
1176		 * entries to store valid bodies in pax interchange
1177		 * format, but not in ustar format.  Since there is no
1178		 * hard and fast way to distinguish pax interchange
1179		 * from earlier archives (the 'x' and 'g' entries are
1180		 * optional, after all), we need a heuristic.
1181		 */
1182		if (archive_entry_size(entry) == 0) {
1183			/* If the size is already zero, we're done. */
1184		}  else if (a->archive.archive_format
1185		    == ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
1186			/* Definitely pax extended; must obey hardlink size. */
1187		} else if (a->archive.archive_format == ARCHIVE_FORMAT_TAR
1188		    || a->archive.archive_format == ARCHIVE_FORMAT_TAR_GNUTAR)
1189		{
1190			/* Old-style or GNU tar: we must ignore the size. */
1191			archive_entry_set_size(entry, 0);
1192			tar->entry_bytes_remaining = 0;
1193		} else if (archive_read_format_tar_bid(a, 50) > 50) {
1194			/*
1195			 * We don't know if it's pax: If the bid
1196			 * function sees a valid ustar header
1197			 * immediately following, then let's ignore
1198			 * the hardlink size.
1199			 */
1200			archive_entry_set_size(entry, 0);
1201			tar->entry_bytes_remaining = 0;
1202		}
1203		/*
1204		 * TODO: There are still two cases I'd like to handle:
1205		 *   = a ustar non-pax archive with a hardlink entry at
1206		 *     end-of-archive.  (Look for block of nulls following?)
1207		 *   = a pax archive that has not seen any pax headers
1208		 *     and has an entry which is a hardlink entry storing
1209		 *     a body containing an uncompressed tar archive.
1210		 * The first is worth addressing; I don't see any reliable
1211		 * way to deal with the second possibility.
1212		 */
1213		break;
1214	case '2': /* Symlink */
1215		archive_entry_set_filetype(entry, AE_IFLNK);
1216		archive_entry_set_size(entry, 0);
1217		tar->entry_bytes_remaining = 0;
1218		if (archive_entry_copy_symlink_l(entry, tar->entry_linkpath.s,
1219		    archive_strlen(&(tar->entry_linkpath)), tar->sconv) != 0) {
1220			err = set_conversion_failed_error(a, tar->sconv,
1221			    "Linkname");
1222			if (err == ARCHIVE_FATAL)
1223				return (err);
1224		}
1225		break;
1226	case '3': /* Character device */
1227		archive_entry_set_filetype(entry, AE_IFCHR);
1228		archive_entry_set_size(entry, 0);
1229		tar->entry_bytes_remaining = 0;
1230		break;
1231	case '4': /* Block device */
1232		archive_entry_set_filetype(entry, AE_IFBLK);
1233		archive_entry_set_size(entry, 0);
1234		tar->entry_bytes_remaining = 0;
1235		break;
1236	case '5': /* Dir */
1237		archive_entry_set_filetype(entry, AE_IFDIR);
1238		archive_entry_set_size(entry, 0);
1239		tar->entry_bytes_remaining = 0;
1240		break;
1241	case '6': /* FIFO device */
1242		archive_entry_set_filetype(entry, AE_IFIFO);
1243		archive_entry_set_size(entry, 0);
1244		tar->entry_bytes_remaining = 0;
1245		break;
1246	case 'D': /* GNU incremental directory type */
1247		/*
1248		 * No special handling is actually required here.
1249		 * It might be nice someday to preprocess the file list and
1250		 * provide it to the client, though.
1251		 */
1252		archive_entry_set_filetype(entry, AE_IFDIR);
1253		break;
1254	case 'M': /* GNU "Multi-volume" (remainder of file from last archive)*/
1255		/*
1256		 * As far as I can tell, this is just like a regular file
1257		 * entry, except that the contents should be _appended_ to
1258		 * the indicated file at the indicated offset.  This may
1259		 * require some API work to fully support.
1260		 */
1261		break;
1262	case 'N': /* Old GNU "long filename" entry. */
1263		/* The body of this entry is a script for renaming
1264		 * previously-extracted entries.  Ugh.  It will never
1265		 * be supported by libarchive. */
1266		archive_entry_set_filetype(entry, AE_IFREG);
1267		break;
1268	case 'S': /* GNU sparse files */
1269		/*
1270		 * Sparse files are really just regular files with
1271		 * sparse information in the extended area.
1272		 */
1273		/* FALLTHROUGH */
1274	default: /* Regular file  and non-standard types */
1275		/*
1276		 * Per POSIX: non-recognized types should always be
1277		 * treated as regular files.
1278		 */
1279		archive_entry_set_filetype(entry, AE_IFREG);
1280		break;
1281	}
1282	return (err);
1283}
1284
1285/*
1286 * Parse out header elements for "old-style" tar archives.
1287 */
1288static int
1289header_old_tar(struct archive_read *a, struct tar *tar,
1290    struct archive_entry *entry, const void *h)
1291{
1292	const struct archive_entry_header_ustar	*header;
1293	int err = ARCHIVE_OK, err2;
1294
1295	/* Copy filename over (to ensure null termination). */
1296	header = (const struct archive_entry_header_ustar *)h;
1297	if (archive_entry_copy_pathname_l(entry,
1298	    header->name, sizeof(header->name), tar->sconv) != 0) {
1299		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1300		if (err == ARCHIVE_FATAL)
1301			return (err);
1302	}
1303
1304	/* Grab rest of common fields */
1305	err2 = header_common(a, tar, entry, h);
1306	if (err > err2)
1307		err = err2;
1308
1309	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1310	return (err);
1311}
1312
1313/*
1314 * Read a Mac AppleDouble-encoded blob of file metadata,
1315 * if there is one.
1316 */
1317static int
1318read_mac_metadata_blob(struct archive_read *a, struct tar *tar,
1319    struct archive_entry *entry, const void *h, size_t *unconsumed)
1320{
1321	int64_t size;
1322	const void *data;
1323	const char *p, *name;
1324	const wchar_t *wp, *wname;
1325
1326	(void)h; /* UNUSED */
1327
1328	wname = wp = archive_entry_pathname_w(entry);
1329	if (wp != NULL) {
1330		/* Find the last path element. */
1331		for (; *wp != L'\0'; ++wp) {
1332			if (wp[0] == '/' && wp[1] != L'\0')
1333				wname = wp + 1;
1334		}
1335		/*
1336		 * If last path element starts with "._", then
1337		 * this is a Mac extension.
1338		 */
1339		if (wname[0] != L'.' || wname[1] != L'_' || wname[2] == L'\0')
1340			return ARCHIVE_OK;
1341	} else {
1342		/* Find the last path element. */
1343		name = p = archive_entry_pathname(entry);
1344		if (p == NULL)
1345			return (ARCHIVE_FAILED);
1346		for (; *p != '\0'; ++p) {
1347			if (p[0] == '/' && p[1] != '\0')
1348				name = p + 1;
1349		}
1350		/*
1351		 * If last path element starts with "._", then
1352		 * this is a Mac extension.
1353		 */
1354		if (name[0] != '.' || name[1] != '_' || name[2] == '\0')
1355			return ARCHIVE_OK;
1356	}
1357
1358 	/* Read the body as a Mac OS metadata blob. */
1359	size = archive_entry_size(entry);
1360
1361	/*
1362	 * TODO: Look beyond the body here to peek at the next header.
1363	 * If it's a regular header (not an extension header)
1364	 * that has the wrong name, just return the current
1365	 * entry as-is, without consuming the body here.
1366	 * That would reduce the risk of us mis-identifying
1367	 * an ordinary file that just happened to have
1368	 * a name starting with "._".
1369	 *
1370	 * Q: Is the above idea really possible?  Even
1371	 * when there are GNU or pax extension entries?
1372	 */
1373	data = __archive_read_ahead(a, (size_t)size, NULL);
1374	if (data == NULL) {
1375		*unconsumed = 0;
1376		return (ARCHIVE_FATAL);
1377	}
1378	archive_entry_copy_mac_metadata(entry, data, (size_t)size);
1379	*unconsumed = (size_t)((size + 511) & ~ 511);
1380	tar_flush_unconsumed(a, unconsumed);
1381	return (tar_read_header(a, tar, entry, unconsumed));
1382}
1383
1384/*
1385 * Parse a file header for a pax extended archive entry.
1386 */
1387static int
1388header_pax_global(struct archive_read *a, struct tar *tar,
1389    struct archive_entry *entry, const void *h, size_t *unconsumed)
1390{
1391	int err;
1392
1393	err = read_body_to_string(a, tar, &(tar->pax_global), h, unconsumed);
1394	if (err != ARCHIVE_OK)
1395		return (err);
1396	err = tar_read_header(a, tar, entry, unconsumed);
1397	return (err);
1398}
1399
1400static int
1401header_pax_extensions(struct archive_read *a, struct tar *tar,
1402    struct archive_entry *entry, const void *h, size_t *unconsumed)
1403{
1404	int err, err2;
1405
1406	err = read_body_to_string(a, tar, &(tar->pax_header), h, unconsumed);
1407	if (err != ARCHIVE_OK)
1408		return (err);
1409
1410	/* Parse the next header. */
1411	err = tar_read_header(a, tar, entry, unconsumed);
1412	if ((err != ARCHIVE_OK) && (err != ARCHIVE_WARN))
1413		return (err);
1414
1415	/*
1416	 * TODO: Parse global/default options into 'entry' struct here
1417	 * before handling file-specific options.
1418	 *
1419	 * This design (parse standard header, then overwrite with pax
1420	 * extended attribute data) usually works well, but isn't ideal;
1421	 * it would be better to parse the pax extended attributes first
1422	 * and then skip any fields in the standard header that were
1423	 * defined in the pax header.
1424	 */
1425	err2 = pax_header(a, tar, entry, tar->pax_header.s);
1426	err =  err_combine(err, err2);
1427	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1428	return (err);
1429}
1430
1431
1432/*
1433 * Parse a file header for a Posix "ustar" archive entry.  This also
1434 * handles "pax" or "extended ustar" entries.
1435 */
1436static int
1437header_ustar(struct archive_read *a, struct tar *tar,
1438    struct archive_entry *entry, const void *h)
1439{
1440	const struct archive_entry_header_ustar	*header;
1441	struct archive_string *as;
1442	int err = ARCHIVE_OK, r;
1443
1444	header = (const struct archive_entry_header_ustar *)h;
1445
1446	/* Copy name into an internal buffer to ensure null-termination. */
1447	as = &(tar->entry_pathname);
1448	if (header->prefix[0]) {
1449		archive_strncpy(as, header->prefix, sizeof(header->prefix));
1450		if (as->s[archive_strlen(as) - 1] != '/')
1451			archive_strappend_char(as, '/');
1452		archive_strncat(as, header->name, sizeof(header->name));
1453	} else {
1454		archive_strncpy(as, header->name, sizeof(header->name));
1455	}
1456	if (archive_entry_copy_pathname_l(entry, as->s, archive_strlen(as),
1457	    tar->sconv) != 0) {
1458		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
1459		if (err == ARCHIVE_FATAL)
1460			return (err);
1461	}
1462
1463	/* Handle rest of common fields. */
1464	r = header_common(a, tar, entry, h);
1465	if (r == ARCHIVE_FATAL)
1466		return (r);
1467	if (r < err)
1468		err = r;
1469
1470	/* Handle POSIX ustar fields. */
1471	if (archive_entry_copy_uname_l(entry,
1472	    header->uname, sizeof(header->uname), tar->sconv) != 0) {
1473		err = set_conversion_failed_error(a, tar->sconv, "Uname");
1474		if (err == ARCHIVE_FATAL)
1475			return (err);
1476	}
1477
1478	if (archive_entry_copy_gname_l(entry,
1479	    header->gname, sizeof(header->gname), tar->sconv) != 0) {
1480		err = set_conversion_failed_error(a, tar->sconv, "Gname");
1481		if (err == ARCHIVE_FATAL)
1482			return (err);
1483	}
1484
1485	/* Parse out device numbers only for char and block specials. */
1486	if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
1487		archive_entry_set_rdevmajor(entry, (dev_t)
1488		    tar_atol(header->rdevmajor, sizeof(header->rdevmajor)));
1489		archive_entry_set_rdevminor(entry, (dev_t)
1490		    tar_atol(header->rdevminor, sizeof(header->rdevminor)));
1491	}
1492
1493	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
1494
1495	return (err);
1496}
1497
1498
1499/*
1500 * Parse the pax extended attributes record.
1501 *
1502 * Returns non-zero if there's an error in the data.
1503 */
1504static int
1505pax_header(struct archive_read *a, struct tar *tar,
1506    struct archive_entry *entry, char *attr)
1507{
1508	size_t attr_length, l, line_length;
1509	char *p;
1510	char *key, *value;
1511	struct archive_string *as;
1512	struct archive_string_conv *sconv;
1513	int err, err2;
1514
1515	attr_length = strlen(attr);
1516	tar->pax_hdrcharset_binary = 0;
1517	archive_string_empty(&(tar->entry_gname));
1518	archive_string_empty(&(tar->entry_linkpath));
1519	archive_string_empty(&(tar->entry_pathname));
1520	archive_string_empty(&(tar->entry_pathname_override));
1521	archive_string_empty(&(tar->entry_uname));
1522	err = ARCHIVE_OK;
1523	while (attr_length > 0) {
1524		/* Parse decimal length field at start of line. */
1525		line_length = 0;
1526		l = attr_length;
1527		p = attr; /* Record start of line. */
1528		while (l>0) {
1529			if (*p == ' ') {
1530				p++;
1531				l--;
1532				break;
1533			}
1534			if (*p < '0' || *p > '9') {
1535				archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1536				    "Ignoring malformed pax extended attributes");
1537				return (ARCHIVE_WARN);
1538			}
1539			line_length *= 10;
1540			line_length += *p - '0';
1541			if (line_length > 999999) {
1542				archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1543				    "Rejecting pax extended attribute > 1MB");
1544				return (ARCHIVE_WARN);
1545			}
1546			p++;
1547			l--;
1548		}
1549
1550		/*
1551		 * Parsed length must be no bigger than available data,
1552		 * at least 1, and the last character of the line must
1553		 * be '\n'.
1554		 */
1555		if (line_length > attr_length
1556		    || line_length < 1
1557		    || attr[line_length - 1] != '\n')
1558		{
1559			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1560			    "Ignoring malformed pax extended attribute");
1561			return (ARCHIVE_WARN);
1562		}
1563
1564		/* Null-terminate the line. */
1565		attr[line_length - 1] = '\0';
1566
1567		/* Find end of key and null terminate it. */
1568		key = p;
1569		if (key[0] == '=')
1570			return (-1);
1571		while (*p && *p != '=')
1572			++p;
1573		if (*p == '\0') {
1574			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
1575			    "Invalid pax extended attributes");
1576			return (ARCHIVE_WARN);
1577		}
1578		*p = '\0';
1579
1580		/* Identify null-terminated 'value' portion. */
1581		value = p + 1;
1582
1583		/* Identify this attribute and set it in the entry. */
1584		err2 = pax_attribute(a, tar, entry, key, value);
1585		if (err2 == ARCHIVE_FATAL)
1586			return (err2);
1587		err = err_combine(err, err2);
1588
1589		/* Skip to next line */
1590		attr += line_length;
1591		attr_length -= line_length;
1592	}
1593
1594	/*
1595	 * PAX format uses UTF-8 as default charset for its metadata
1596	 * unless hdrcharset=BINARY is present in its header.
1597	 * We apply the charset specified by the hdrcharset option only
1598	 * when the hdrcharset attribute(in PAX header) is BINARY because
1599	 * we respect the charset described in PAX header and BINARY also
1600	 * means that metadata(filename,uname and gname) character-set
1601	 * is unknown.
1602	 */
1603	if (tar->pax_hdrcharset_binary)
1604		sconv = tar->opt_sconv;
1605	else {
1606		sconv = archive_string_conversion_from_charset(
1607		    &(a->archive), "UTF-8", 1);
1608		if (sconv == NULL)
1609			return (ARCHIVE_FATAL);
1610		if (tar->compat_2x)
1611			archive_string_conversion_set_opt(sconv,
1612			    SCONV_SET_OPT_UTF8_LIBARCHIVE2X);
1613	}
1614
1615	if (archive_strlen(&(tar->entry_gname)) > 0) {
1616		if (archive_entry_copy_gname_l(entry, tar->entry_gname.s,
1617		    archive_strlen(&(tar->entry_gname)), sconv) != 0) {
1618			err = set_conversion_failed_error(a, sconv, "Gname");
1619			if (err == ARCHIVE_FATAL)
1620				return (err);
1621			/* Use a converted an original name. */
1622			archive_entry_copy_gname(entry, tar->entry_gname.s);
1623		}
1624	}
1625	if (archive_strlen(&(tar->entry_linkpath)) > 0) {
1626		if (archive_entry_copy_link_l(entry, tar->entry_linkpath.s,
1627		    archive_strlen(&(tar->entry_linkpath)), sconv) != 0) {
1628			err = set_conversion_failed_error(a, sconv, "Linkname");
1629			if (err == ARCHIVE_FATAL)
1630				return (err);
1631			/* Use a converted an original name. */
1632			archive_entry_copy_link(entry, tar->entry_linkpath.s);
1633		}
1634	}
1635	/*
1636	 * Some extensions (such as the GNU sparse file extensions)
1637	 * deliberately store a synthetic name under the regular 'path'
1638	 * attribute and the real file name under a different attribute.
1639	 * Since we're supposed to not care about the order, we
1640	 * have no choice but to store all of the various filenames
1641	 * we find and figure it all out afterwards.  This is the
1642	 * figuring out part.
1643	 */
1644	as = NULL;
1645	if (archive_strlen(&(tar->entry_pathname_override)) > 0)
1646		as = &(tar->entry_pathname_override);
1647	else if (archive_strlen(&(tar->entry_pathname)) > 0)
1648		as = &(tar->entry_pathname);
1649	if (as != NULL) {
1650		if (archive_entry_copy_pathname_l(entry, as->s,
1651		    archive_strlen(as), sconv) != 0) {
1652			err = set_conversion_failed_error(a, sconv, "Pathname");
1653			if (err == ARCHIVE_FATAL)
1654				return (err);
1655			/* Use a converted an original name. */
1656			archive_entry_copy_pathname(entry, as->s);
1657		}
1658	}
1659	if (archive_strlen(&(tar->entry_uname)) > 0) {
1660		if (archive_entry_copy_uname_l(entry, tar->entry_uname.s,
1661		    archive_strlen(&(tar->entry_uname)), sconv) != 0) {
1662			err = set_conversion_failed_error(a, sconv, "Uname");
1663			if (err == ARCHIVE_FATAL)
1664				return (err);
1665			/* Use a converted an original name. */
1666			archive_entry_copy_uname(entry, tar->entry_uname.s);
1667		}
1668	}
1669	return (err);
1670}
1671
1672static int
1673pax_attribute_xattr(struct archive_entry *entry,
1674	const char *name, const char *value)
1675{
1676	char *name_decoded;
1677	void *value_decoded;
1678	size_t value_len;
1679
1680	if (strlen(name) < 18 || (memcmp(name, "LIBARCHIVE.xattr.", 17)) != 0)
1681		return 3;
1682
1683	name += 17;
1684
1685	/* URL-decode name */
1686	name_decoded = url_decode(name);
1687	if (name_decoded == NULL)
1688		return 2;
1689
1690	/* Base-64 decode value */
1691	value_decoded = base64_decode(value, strlen(value), &value_len);
1692	if (value_decoded == NULL) {
1693		free(name_decoded);
1694		return 1;
1695	}
1696
1697	archive_entry_xattr_add_entry(entry, name_decoded,
1698		value_decoded, value_len);
1699
1700	free(name_decoded);
1701	free(value_decoded);
1702	return 0;
1703}
1704
1705/*
1706 * Parse a single key=value attribute.  key/value pointers are
1707 * assumed to point into reasonably long-lived storage.
1708 *
1709 * Note that POSIX reserves all-lowercase keywords.  Vendor-specific
1710 * extensions should always have keywords of the form "VENDOR.attribute"
1711 * In particular, it's quite feasible to support many different
1712 * vendor extensions here.  I'm using "LIBARCHIVE" for extensions
1713 * unique to this library.
1714 *
1715 * Investigate other vendor-specific extensions and see if
1716 * any of them look useful.
1717 */
1718static int
1719pax_attribute(struct archive_read *a, struct tar *tar,
1720    struct archive_entry *entry, const char *key, const char *value)
1721{
1722	int64_t s;
1723	long n;
1724	int err = ARCHIVE_OK, r;
1725
1726#ifndef __FreeBSD__
1727	if (value == NULL)
1728		value = "";	/* Disable compiler warning; do not pass
1729				 * NULL pointer to strlen().  */
1730#endif
1731	switch (key[0]) {
1732	case 'G':
1733		/* GNU "0.0" sparse pax format. */
1734		if (strcmp(key, "GNU.sparse.numblocks") == 0) {
1735			tar->sparse_offset = -1;
1736			tar->sparse_numbytes = -1;
1737			tar->sparse_gnu_major = 0;
1738			tar->sparse_gnu_minor = 0;
1739		}
1740		if (strcmp(key, "GNU.sparse.offset") == 0) {
1741			tar->sparse_offset = tar_atol10(value, strlen(value));
1742			if (tar->sparse_numbytes != -1) {
1743				if (gnu_add_sparse_entry(a, tar,
1744				    tar->sparse_offset, tar->sparse_numbytes)
1745				    != ARCHIVE_OK)
1746					return (ARCHIVE_FATAL);
1747				tar->sparse_offset = -1;
1748				tar->sparse_numbytes = -1;
1749			}
1750		}
1751		if (strcmp(key, "GNU.sparse.numbytes") == 0) {
1752			tar->sparse_numbytes = tar_atol10(value, strlen(value));
1753			if (tar->sparse_numbytes != -1) {
1754				if (gnu_add_sparse_entry(a, tar,
1755				    tar->sparse_offset, tar->sparse_numbytes)
1756				    != ARCHIVE_OK)
1757					return (ARCHIVE_FATAL);
1758				tar->sparse_offset = -1;
1759				tar->sparse_numbytes = -1;
1760			}
1761		}
1762		if (strcmp(key, "GNU.sparse.size") == 0) {
1763			tar->realsize = tar_atol10(value, strlen(value));
1764			archive_entry_set_size(entry, tar->realsize);
1765		}
1766
1767		/* GNU "0.1" sparse pax format. */
1768		if (strcmp(key, "GNU.sparse.map") == 0) {
1769			tar->sparse_gnu_major = 0;
1770			tar->sparse_gnu_minor = 1;
1771			if (gnu_sparse_01_parse(a, tar, value) != ARCHIVE_OK)
1772				return (ARCHIVE_WARN);
1773		}
1774
1775		/* GNU "1.0" sparse pax format */
1776		if (strcmp(key, "GNU.sparse.major") == 0) {
1777			tar->sparse_gnu_major = (int)tar_atol10(value, strlen(value));
1778			tar->sparse_gnu_pending = 1;
1779		}
1780		if (strcmp(key, "GNU.sparse.minor") == 0) {
1781			tar->sparse_gnu_minor = (int)tar_atol10(value, strlen(value));
1782			tar->sparse_gnu_pending = 1;
1783		}
1784		if (strcmp(key, "GNU.sparse.name") == 0) {
1785			/*
1786			 * The real filename; when storing sparse
1787			 * files, GNU tar puts a synthesized name into
1788			 * the regular 'path' attribute in an attempt
1789			 * to limit confusion. ;-)
1790			 */
1791			archive_strcpy(&(tar->entry_pathname_override), value);
1792		}
1793		if (strcmp(key, "GNU.sparse.realsize") == 0) {
1794			tar->realsize = tar_atol10(value, strlen(value));
1795			archive_entry_set_size(entry, tar->realsize);
1796		}
1797		break;
1798	case 'L':
1799		/* Our extensions */
1800/* TODO: Handle arbitrary extended attributes... */
1801/*
1802		if (strcmp(key, "LIBARCHIVE.xxxxxxx") == 0)
1803			archive_entry_set_xxxxxx(entry, value);
1804*/
1805		if (strcmp(key, "LIBARCHIVE.creationtime") == 0) {
1806			pax_time(value, &s, &n);
1807			archive_entry_set_birthtime(entry, s, n);
1808		}
1809		if (memcmp(key, "LIBARCHIVE.xattr.", 17) == 0)
1810			pax_attribute_xattr(entry, key, value);
1811		break;
1812	case 'S':
1813		/* We support some keys used by the "star" archiver */
1814		if (strcmp(key, "SCHILY.acl.access") == 0) {
1815			if (tar->sconv_acl == NULL) {
1816				tar->sconv_acl =
1817				    archive_string_conversion_from_charset(
1818					&(a->archive), "UTF-8", 1);
1819				if (tar->sconv_acl == NULL)
1820					return (ARCHIVE_FATAL);
1821			}
1822
1823			r = archive_acl_parse_l(archive_entry_acl(entry),
1824			    value, ARCHIVE_ENTRY_ACL_TYPE_ACCESS,
1825			    tar->sconv_acl);
1826			if (r != ARCHIVE_OK) {
1827				err = r;
1828				if (err == ARCHIVE_FATAL) {
1829					archive_set_error(&a->archive, ENOMEM,
1830					    "Can't allocate memory for "
1831					    "SCHILY.acl.access");
1832					return (err);
1833				}
1834				archive_set_error(&a->archive,
1835				    ARCHIVE_ERRNO_MISC,
1836				    "Parse error: SCHILY.acl.access");
1837			}
1838		} else if (strcmp(key, "SCHILY.acl.default") == 0) {
1839			if (tar->sconv_acl == NULL) {
1840				tar->sconv_acl =
1841				    archive_string_conversion_from_charset(
1842					&(a->archive), "UTF-8", 1);
1843				if (tar->sconv_acl == NULL)
1844					return (ARCHIVE_FATAL);
1845			}
1846
1847			r = archive_acl_parse_l(archive_entry_acl(entry),
1848			    value, ARCHIVE_ENTRY_ACL_TYPE_DEFAULT,
1849			    tar->sconv_acl);
1850			if (r != ARCHIVE_OK) {
1851				err = r;
1852				if (err == ARCHIVE_FATAL) {
1853					archive_set_error(&a->archive, ENOMEM,
1854					    "Can't allocate memory for "
1855					    "SCHILY.acl.default");
1856					return (err);
1857				}
1858				archive_set_error(&a->archive,
1859				    ARCHIVE_ERRNO_MISC,
1860				    "Parse error: SCHILY.acl.default");
1861			}
1862		} else if (strcmp(key, "SCHILY.devmajor") == 0) {
1863			archive_entry_set_rdevmajor(entry,
1864			    (dev_t)tar_atol10(value, strlen(value)));
1865		} else if (strcmp(key, "SCHILY.devminor") == 0) {
1866			archive_entry_set_rdevminor(entry,
1867			    (dev_t)tar_atol10(value, strlen(value)));
1868		} else if (strcmp(key, "SCHILY.fflags") == 0) {
1869			archive_entry_copy_fflags_text(entry, value);
1870		} else if (strcmp(key, "SCHILY.dev") == 0) {
1871			archive_entry_set_dev(entry,
1872			    (dev_t)tar_atol10(value, strlen(value)));
1873		} else if (strcmp(key, "SCHILY.ino") == 0) {
1874			archive_entry_set_ino(entry,
1875			    tar_atol10(value, strlen(value)));
1876		} else if (strcmp(key, "SCHILY.nlink") == 0) {
1877			archive_entry_set_nlink(entry, (unsigned)
1878			    tar_atol10(value, strlen(value)));
1879		} else if (strcmp(key, "SCHILY.realsize") == 0) {
1880			tar->realsize = tar_atol10(value, strlen(value));
1881			archive_entry_set_size(entry, tar->realsize);
1882		} else if (strcmp(key, "SUN.holesdata") == 0) {
1883			/* A Solaris extension for sparse. */
1884			r = solaris_sparse_parse(a, tar, entry, value);
1885			if (r < err) {
1886				if (r == ARCHIVE_FATAL)
1887					return (r);
1888				err = r;
1889				archive_set_error(&a->archive,
1890				    ARCHIVE_ERRNO_MISC,
1891				    "Parse error: SUN.holesdata");
1892			}
1893		}
1894		break;
1895	case 'a':
1896		if (strcmp(key, "atime") == 0) {
1897			pax_time(value, &s, &n);
1898			archive_entry_set_atime(entry, s, n);
1899		}
1900		break;
1901	case 'c':
1902		if (strcmp(key, "ctime") == 0) {
1903			pax_time(value, &s, &n);
1904			archive_entry_set_ctime(entry, s, n);
1905		} else if (strcmp(key, "charset") == 0) {
1906			/* TODO: Publish charset information in entry. */
1907		} else if (strcmp(key, "comment") == 0) {
1908			/* TODO: Publish comment in entry. */
1909		}
1910		break;
1911	case 'g':
1912		if (strcmp(key, "gid") == 0) {
1913			archive_entry_set_gid(entry,
1914			    tar_atol10(value, strlen(value)));
1915		} else if (strcmp(key, "gname") == 0) {
1916			archive_strcpy(&(tar->entry_gname), value);
1917		}
1918		break;
1919	case 'h':
1920		if (strcmp(key, "hdrcharset") == 0) {
1921			if (strcmp(value, "BINARY") == 0)
1922				/* Binary  mode. */
1923				tar->pax_hdrcharset_binary = 1;
1924			else if (strcmp(value, "ISO-IR 10646 2000 UTF-8") == 0)
1925				tar->pax_hdrcharset_binary = 0;
1926		}
1927		break;
1928	case 'l':
1929		/* pax interchange doesn't distinguish hardlink vs. symlink. */
1930		if (strcmp(key, "linkpath") == 0) {
1931			archive_strcpy(&(tar->entry_linkpath), value);
1932		}
1933		break;
1934	case 'm':
1935		if (strcmp(key, "mtime") == 0) {
1936			pax_time(value, &s, &n);
1937			archive_entry_set_mtime(entry, s, n);
1938		}
1939		break;
1940	case 'p':
1941		if (strcmp(key, "path") == 0) {
1942			archive_strcpy(&(tar->entry_pathname), value);
1943		}
1944		break;
1945	case 'r':
1946		/* POSIX has reserved 'realtime.*' */
1947		break;
1948	case 's':
1949		/* POSIX has reserved 'security.*' */
1950		/* Someday: if (strcmp(key, "security.acl") == 0) { ... } */
1951		if (strcmp(key, "size") == 0) {
1952			/* "size" is the size of the data in the entry. */
1953			tar->entry_bytes_remaining
1954			    = tar_atol10(value, strlen(value));
1955			/*
1956			 * But, "size" is not necessarily the size of
1957			 * the file on disk; if this is a sparse file,
1958			 * the disk size may have already been set from
1959			 * GNU.sparse.realsize or GNU.sparse.size or
1960			 * an old GNU header field or SCHILY.realsize
1961			 * or ....
1962			 */
1963			if (tar->realsize < 0) {
1964				archive_entry_set_size(entry,
1965				    tar->entry_bytes_remaining);
1966				tar->realsize
1967				    = tar->entry_bytes_remaining;
1968			}
1969		}
1970		break;
1971	case 'u':
1972		if (strcmp(key, "uid") == 0) {
1973			archive_entry_set_uid(entry,
1974			    tar_atol10(value, strlen(value)));
1975		} else if (strcmp(key, "uname") == 0) {
1976			archive_strcpy(&(tar->entry_uname), value);
1977		}
1978		break;
1979	}
1980	return (err);
1981}
1982
1983
1984
1985/*
1986 * parse a decimal time value, which may include a fractional portion
1987 */
1988static void
1989pax_time(const char *p, int64_t *ps, long *pn)
1990{
1991	char digit;
1992	int64_t	s;
1993	unsigned long l;
1994	int sign;
1995	int64_t limit, last_digit_limit;
1996
1997	limit = INT64_MAX / 10;
1998	last_digit_limit = INT64_MAX % 10;
1999
2000	s = 0;
2001	sign = 1;
2002	if (*p == '-') {
2003		sign = -1;
2004		p++;
2005	}
2006	while (*p >= '0' && *p <= '9') {
2007		digit = *p - '0';
2008		if (s > limit ||
2009		    (s == limit && digit > last_digit_limit)) {
2010			s = INT64_MAX;
2011			break;
2012		}
2013		s = (s * 10) + digit;
2014		++p;
2015	}
2016
2017	*ps = s * sign;
2018
2019	/* Calculate nanoseconds. */
2020	*pn = 0;
2021
2022	if (*p != '.')
2023		return;
2024
2025	l = 100000000UL;
2026	do {
2027		++p;
2028		if (*p >= '0' && *p <= '9')
2029			*pn += (*p - '0') * l;
2030		else
2031			break;
2032	} while (l /= 10);
2033}
2034
2035/*
2036 * Parse GNU tar header
2037 */
2038static int
2039header_gnutar(struct archive_read *a, struct tar *tar,
2040    struct archive_entry *entry, const void *h, size_t *unconsumed)
2041{
2042	const struct archive_entry_header_gnutar *header;
2043	int64_t t;
2044	int err = ARCHIVE_OK;
2045
2046	/*
2047	 * GNU header is like POSIX ustar, except 'prefix' is
2048	 * replaced with some other fields. This also means the
2049	 * filename is stored as in old-style archives.
2050	 */
2051
2052	/* Grab fields common to all tar variants. */
2053	err = header_common(a, tar, entry, h);
2054	if (err == ARCHIVE_FATAL)
2055		return (err);
2056
2057	/* Copy filename over (to ensure null termination). */
2058	header = (const struct archive_entry_header_gnutar *)h;
2059	if (archive_entry_copy_pathname_l(entry,
2060	    header->name, sizeof(header->name), tar->sconv) != 0) {
2061		err = set_conversion_failed_error(a, tar->sconv, "Pathname");
2062		if (err == ARCHIVE_FATAL)
2063			return (err);
2064	}
2065
2066	/* Fields common to ustar and GNU */
2067	/* XXX Can the following be factored out since it's common
2068	 * to ustar and gnu tar?  Is it okay to move it down into
2069	 * header_common, perhaps?  */
2070	if (archive_entry_copy_uname_l(entry,
2071	    header->uname, sizeof(header->uname), tar->sconv) != 0) {
2072		err = set_conversion_failed_error(a, tar->sconv, "Uname");
2073		if (err == ARCHIVE_FATAL)
2074			return (err);
2075	}
2076
2077	if (archive_entry_copy_gname_l(entry,
2078	    header->gname, sizeof(header->gname), tar->sconv) != 0) {
2079		err = set_conversion_failed_error(a, tar->sconv, "Gname");
2080		if (err == ARCHIVE_FATAL)
2081			return (err);
2082	}
2083
2084	/* Parse out device numbers only for char and block specials */
2085	if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
2086		archive_entry_set_rdevmajor(entry, (dev_t)
2087		    tar_atol(header->rdevmajor, sizeof(header->rdevmajor)));
2088		archive_entry_set_rdevminor(entry, (dev_t)
2089		    tar_atol(header->rdevminor, sizeof(header->rdevminor)));
2090	} else
2091		archive_entry_set_rdev(entry, 0);
2092
2093	tar->entry_padding = 0x1ff & (-tar->entry_bytes_remaining);
2094
2095	/* Grab GNU-specific fields. */
2096	t = tar_atol(header->atime, sizeof(header->atime));
2097	if (t > 0)
2098		archive_entry_set_atime(entry, t, 0);
2099	t = tar_atol(header->ctime, sizeof(header->ctime));
2100	if (t > 0)
2101		archive_entry_set_ctime(entry, t, 0);
2102
2103	if (header->realsize[0] != 0) {
2104		tar->realsize
2105		    = tar_atol(header->realsize, sizeof(header->realsize));
2106		archive_entry_set_size(entry, tar->realsize);
2107	}
2108
2109	if (header->sparse[0].offset[0] != 0) {
2110		if (gnu_sparse_old_read(a, tar, header, unconsumed)
2111		    != ARCHIVE_OK)
2112			return (ARCHIVE_FATAL);
2113	} else {
2114		if (header->isextended[0] != 0) {
2115			/* XXX WTF? XXX */
2116		}
2117	}
2118
2119	return (err);
2120}
2121
2122static int
2123gnu_add_sparse_entry(struct archive_read *a, struct tar *tar,
2124    int64_t offset, int64_t remaining)
2125{
2126	struct sparse_block *p;
2127
2128	p = (struct sparse_block *)malloc(sizeof(*p));
2129	if (p == NULL) {
2130		archive_set_error(&a->archive, ENOMEM, "Out of memory");
2131		return (ARCHIVE_FATAL);
2132	}
2133	memset(p, 0, sizeof(*p));
2134	if (tar->sparse_last != NULL)
2135		tar->sparse_last->next = p;
2136	else
2137		tar->sparse_list = p;
2138	tar->sparse_last = p;
2139	if (remaining < 0 || offset < 0) {
2140		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Malformed sparse map data");
2141		return (ARCHIVE_FATAL);
2142	}
2143	p->offset = offset;
2144	p->remaining = remaining;
2145	return (ARCHIVE_OK);
2146}
2147
2148static void
2149gnu_clear_sparse_list(struct tar *tar)
2150{
2151	struct sparse_block *p;
2152
2153	while (tar->sparse_list != NULL) {
2154		p = tar->sparse_list;
2155		tar->sparse_list = p->next;
2156		free(p);
2157	}
2158	tar->sparse_last = NULL;
2159}
2160
2161/*
2162 * GNU tar old-format sparse data.
2163 *
2164 * GNU old-format sparse data is stored in a fixed-field
2165 * format.  Offset/size values are 11-byte octal fields (same
2166 * format as 'size' field in ustart header).  These are
2167 * stored in the header, allocating subsequent header blocks
2168 * as needed.  Extending the header in this way is a pretty
2169 * severe POSIX violation; this design has earned GNU tar a
2170 * lot of criticism.
2171 */
2172
2173static int
2174gnu_sparse_old_read(struct archive_read *a, struct tar *tar,
2175    const struct archive_entry_header_gnutar *header, size_t *unconsumed)
2176{
2177	ssize_t bytes_read;
2178	const void *data;
2179	struct extended {
2180		struct gnu_sparse sparse[21];
2181		char	isextended[1];
2182		char	padding[7];
2183	};
2184	const struct extended *ext;
2185
2186	if (gnu_sparse_old_parse(a, tar, header->sparse, 4) != ARCHIVE_OK)
2187		return (ARCHIVE_FATAL);
2188	if (header->isextended[0] == 0)
2189		return (ARCHIVE_OK);
2190
2191	do {
2192		tar_flush_unconsumed(a, unconsumed);
2193		data = __archive_read_ahead(a, 512, &bytes_read);
2194		if (bytes_read < 0)
2195			return (ARCHIVE_FATAL);
2196		if (bytes_read < 512) {
2197			archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
2198			    "Truncated tar archive "
2199			    "detected while reading sparse file data");
2200			return (ARCHIVE_FATAL);
2201		}
2202		*unconsumed = 512;
2203		ext = (const struct extended *)data;
2204		if (gnu_sparse_old_parse(a, tar, ext->sparse, 21) != ARCHIVE_OK)
2205			return (ARCHIVE_FATAL);
2206	} while (ext->isextended[0] != 0);
2207	if (tar->sparse_list != NULL)
2208		tar->entry_offset = tar->sparse_list->offset;
2209	return (ARCHIVE_OK);
2210}
2211
2212static int
2213gnu_sparse_old_parse(struct archive_read *a, struct tar *tar,
2214    const struct gnu_sparse *sparse, int length)
2215{
2216	while (length > 0 && sparse->offset[0] != 0) {
2217		if (gnu_add_sparse_entry(a, tar,
2218		    tar_atol(sparse->offset, sizeof(sparse->offset)),
2219		    tar_atol(sparse->numbytes, sizeof(sparse->numbytes)))
2220		    != ARCHIVE_OK)
2221			return (ARCHIVE_FATAL);
2222		sparse++;
2223		length--;
2224	}
2225	return (ARCHIVE_OK);
2226}
2227
2228/*
2229 * GNU tar sparse format 0.0
2230 *
2231 * Beginning with GNU tar 1.15, sparse files are stored using
2232 * information in the pax extended header.  The GNU tar maintainers
2233 * have gone through a number of variations in the process of working
2234 * out this scheme; fortunately, they're all numbered.
2235 *
2236 * Sparse format 0.0 uses attribute GNU.sparse.numblocks to store the
2237 * number of blocks, and GNU.sparse.offset/GNU.sparse.numbytes to
2238 * store offset/size for each block.  The repeated instances of these
2239 * latter fields violate the pax specification (which frowns on
2240 * duplicate keys), so this format was quickly replaced.
2241 */
2242
2243/*
2244 * GNU tar sparse format 0.1
2245 *
2246 * This version replaced the offset/numbytes attributes with
2247 * a single "map" attribute that stored a list of integers.  This
2248 * format had two problems: First, the "map" attribute could be very
2249 * long, which caused problems for some implementations.  More
2250 * importantly, the sparse data was lost when extracted by archivers
2251 * that didn't recognize this extension.
2252 */
2253
2254static int
2255gnu_sparse_01_parse(struct archive_read *a, struct tar *tar, const char *p)
2256{
2257	const char *e;
2258	int64_t offset = -1, size = -1;
2259
2260	for (;;) {
2261		e = p;
2262		while (*e != '\0' && *e != ',') {
2263			if (*e < '0' || *e > '9')
2264				return (ARCHIVE_WARN);
2265			e++;
2266		}
2267		if (offset < 0) {
2268			offset = tar_atol10(p, e - p);
2269			if (offset < 0)
2270				return (ARCHIVE_WARN);
2271		} else {
2272			size = tar_atol10(p, e - p);
2273			if (size < 0)
2274				return (ARCHIVE_WARN);
2275			if (gnu_add_sparse_entry(a, tar, offset, size)
2276			    != ARCHIVE_OK)
2277				return (ARCHIVE_FATAL);
2278			offset = -1;
2279		}
2280		if (*e == '\0')
2281			return (ARCHIVE_OK);
2282		p = e + 1;
2283	}
2284}
2285
2286/*
2287 * GNU tar sparse format 1.0
2288 *
2289 * The idea: The offset/size data is stored as a series of base-10
2290 * ASCII numbers prepended to the file data, so that dearchivers that
2291 * don't support this format will extract the block map along with the
2292 * data and a separate post-process can restore the sparseness.
2293 *
2294 * Unfortunately, GNU tar 1.16 had a bug that added unnecessary
2295 * padding to the body of the file when using this format.  GNU tar
2296 * 1.17 corrected this bug without bumping the version number, so
2297 * it's not possible to support both variants.  This code supports
2298 * the later variant at the expense of not supporting the former.
2299 *
2300 * This variant also replaced GNU.sparse.size with GNU.sparse.realsize
2301 * and introduced the GNU.sparse.major/GNU.sparse.minor attributes.
2302 */
2303
2304/*
2305 * Read the next line from the input, and parse it as a decimal
2306 * integer followed by '\n'.  Returns positive integer value or
2307 * negative on error.
2308 */
2309static int64_t
2310gnu_sparse_10_atol(struct archive_read *a, struct tar *tar,
2311    int64_t *remaining, size_t *unconsumed)
2312{
2313	int64_t l, limit, last_digit_limit;
2314	const char *p;
2315	ssize_t bytes_read;
2316	int base, digit;
2317
2318	base = 10;
2319	limit = INT64_MAX / base;
2320	last_digit_limit = INT64_MAX % base;
2321
2322	/*
2323	 * Skip any lines starting with '#'; GNU tar specs
2324	 * don't require this, but they should.
2325	 */
2326	do {
2327		bytes_read = readline(a, tar, &p,
2328			(ssize_t)tar_min(*remaining, 100), unconsumed);
2329		if (bytes_read <= 0)
2330			return (ARCHIVE_FATAL);
2331		*remaining -= bytes_read;
2332	} while (p[0] == '#');
2333
2334	l = 0;
2335	while (bytes_read > 0) {
2336		if (*p == '\n')
2337			return (l);
2338		if (*p < '0' || *p >= '0' + base)
2339			return (ARCHIVE_WARN);
2340		digit = *p - '0';
2341		if (l > limit || (l == limit && digit > last_digit_limit))
2342			l = INT64_MAX; /* Truncate on overflow. */
2343		else
2344			l = (l * base) + digit;
2345		p++;
2346		bytes_read--;
2347	}
2348	/* TODO: Error message. */
2349	return (ARCHIVE_WARN);
2350}
2351
2352/*
2353 * Returns length (in bytes) of the sparse data description
2354 * that was read.
2355 */
2356static ssize_t
2357gnu_sparse_10_read(struct archive_read *a, struct tar *tar, size_t *unconsumed)
2358{
2359	ssize_t bytes_read;
2360	int entries;
2361	int64_t offset, size, to_skip, remaining;
2362
2363	/* Clear out the existing sparse list. */
2364	gnu_clear_sparse_list(tar);
2365
2366	remaining = tar->entry_bytes_remaining;
2367
2368	/* Parse entries. */
2369	entries = (int)gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2370	if (entries < 0)
2371		return (ARCHIVE_FATAL);
2372	/* Parse the individual entries. */
2373	while (entries-- > 0) {
2374		/* Parse offset/size */
2375		offset = gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2376		if (offset < 0)
2377			return (ARCHIVE_FATAL);
2378		size = gnu_sparse_10_atol(a, tar, &remaining, unconsumed);
2379		if (size < 0)
2380			return (ARCHIVE_FATAL);
2381		/* Add a new sparse entry. */
2382		if (gnu_add_sparse_entry(a, tar, offset, size) != ARCHIVE_OK)
2383			return (ARCHIVE_FATAL);
2384	}
2385	/* Skip rest of block... */
2386	tar_flush_unconsumed(a, unconsumed);
2387	bytes_read = (ssize_t)(tar->entry_bytes_remaining - remaining);
2388	to_skip = 0x1ff & -bytes_read;
2389	if (to_skip != __archive_read_consume(a, to_skip))
2390		return (ARCHIVE_FATAL);
2391	return ((ssize_t)(bytes_read + to_skip));
2392}
2393
2394/*
2395 * Solaris pax extension for a sparse file. This is recorded with the
2396 * data and hole pairs. The way recording sparse information by Solaris'
2397 * pax simply indicates where data and sparse are, so the stored contents
2398 * consist of both data and hole.
2399 */
2400static int
2401solaris_sparse_parse(struct archive_read *a, struct tar *tar,
2402    struct archive_entry *entry, const char *p)
2403{
2404	const char *e;
2405	int64_t start, end;
2406	int hole = 1;
2407
2408	(void)entry; /* UNUSED */
2409
2410	end = 0;
2411	if (*p == ' ')
2412		p++;
2413	else
2414		return (ARCHIVE_WARN);
2415	for (;;) {
2416		e = p;
2417		while (*e != '\0' && *e != ' ') {
2418			if (*e < '0' || *e > '9')
2419				return (ARCHIVE_WARN);
2420			e++;
2421		}
2422		start = end;
2423		end = tar_atol10(p, e - p);
2424		if (end < 0)
2425			return (ARCHIVE_WARN);
2426		if (start < end) {
2427			if (gnu_add_sparse_entry(a, tar, start,
2428			    end - start) != ARCHIVE_OK)
2429				return (ARCHIVE_FATAL);
2430			tar->sparse_last->hole = hole;
2431		}
2432		if (*e == '\0')
2433			return (ARCHIVE_OK);
2434		p = e + 1;
2435		hole = hole == 0;
2436	}
2437}
2438
2439/*-
2440 * Convert text->integer.
2441 *
2442 * Traditional tar formats (including POSIX) specify base-8 for
2443 * all of the standard numeric fields.  This is a significant limitation
2444 * in practice:
2445 *   = file size is limited to 8GB
2446 *   = rdevmajor and rdevminor are limited to 21 bits
2447 *   = uid/gid are limited to 21 bits
2448 *
2449 * There are two workarounds for this:
2450 *   = pax extended headers, which use variable-length string fields
2451 *   = GNU tar and STAR both allow either base-8 or base-256 in
2452 *      most fields.  The high bit is set to indicate base-256.
2453 *
2454 * On read, this implementation supports both extensions.
2455 */
2456static int64_t
2457tar_atol(const char *p, size_t char_cnt)
2458{
2459	/*
2460	 * Technically, GNU tar considers a field to be in base-256
2461	 * only if the first byte is 0xff or 0x80.
2462	 */
2463	if (*p & 0x80)
2464		return (tar_atol256(p, char_cnt));
2465	return (tar_atol8(p, char_cnt));
2466}
2467
2468/*
2469 * Note that this implementation does not (and should not!) obey
2470 * locale settings; you cannot simply substitute strtol here, since
2471 * it does obey locale.
2472 */
2473static int64_t
2474tar_atol_base_n(const char *p, size_t char_cnt, int base)
2475{
2476	int64_t	l, maxval, limit, last_digit_limit;
2477	int digit, sign;
2478
2479	maxval = INT64_MAX;
2480	limit = INT64_MAX / base;
2481	last_digit_limit = INT64_MAX % base;
2482
2483	/* the pointer will not be dereferenced if char_cnt is zero
2484	 * due to the way the && operator is evaulated.
2485	 */
2486	while (char_cnt != 0 && (*p == ' ' || *p == '\t')) {
2487		p++;
2488		char_cnt--;
2489	}
2490
2491	sign = 1;
2492	if (char_cnt != 0 && *p == '-') {
2493		sign = -1;
2494		p++;
2495		char_cnt--;
2496
2497		maxval = INT64_MIN;
2498		limit = -(INT64_MIN / base);
2499		last_digit_limit = INT64_MIN % base;
2500	}
2501
2502	l = 0;
2503	if (char_cnt != 0) {
2504		digit = *p - '0';
2505		while (digit >= 0 && digit < base  && char_cnt != 0) {
2506			if (l>limit || (l == limit && digit > last_digit_limit)) {
2507				return maxval; /* Truncate on overflow. */
2508			}
2509			l = (l * base) + digit;
2510			digit = *++p - '0';
2511			char_cnt--;
2512		}
2513	}
2514	return (sign < 0) ? -l : l;
2515}
2516
2517static int64_t
2518tar_atol8(const char *p, size_t char_cnt)
2519{
2520	return tar_atol_base_n(p, char_cnt, 8);
2521}
2522
2523static int64_t
2524tar_atol10(const char *p, size_t char_cnt)
2525{
2526	return tar_atol_base_n(p, char_cnt, 10);
2527}
2528
2529/*
2530 * Parse a base-256 integer.  This is just a variable-length
2531 * twos-complement signed binary value in big-endian order, except
2532 * that the high-order bit is ignored.  The values here can be up to
2533 * 12 bytes, so we need to be careful about overflowing 64-bit
2534 * (8-byte) integers.
2535 *
2536 * This code unashamedly assumes that the local machine uses 8-bit
2537 * bytes and twos-complement arithmetic.
2538 */
2539static int64_t
2540tar_atol256(const char *_p, size_t char_cnt)
2541{
2542	uint64_t l;
2543	const unsigned char *p = (const unsigned char *)_p;
2544	unsigned char c, neg;
2545
2546	/* Extend 7-bit 2s-comp to 8-bit 2s-comp, decide sign. */
2547	c = *p;
2548	if (c & 0x40) {
2549		neg = 0xff;
2550		c |= 0x80;
2551		l = ~ARCHIVE_LITERAL_ULL(0);
2552	} else {
2553		neg = 0;
2554		c &= 0x7f;
2555		l = 0;
2556	}
2557
2558	/* If more than 8 bytes, check that we can ignore
2559	 * high-order bits without overflow. */
2560	while (char_cnt > sizeof(int64_t)) {
2561		--char_cnt;
2562		if (c != neg)
2563			return neg ? INT64_MIN : INT64_MAX;
2564		c = *++p;
2565	}
2566
2567	/* c is first byte that fits; if sign mismatch, return overflow */
2568	if ((c ^ neg) & 0x80) {
2569		return neg ? INT64_MIN : INT64_MAX;
2570	}
2571
2572	/* Accumulate remaining bytes. */
2573	while (--char_cnt > 0) {
2574		l = (l << 8) | c;
2575		c = *++p;
2576	}
2577	l = (l << 8) | c;
2578	/* Return signed twos-complement value. */
2579	return (int64_t)(l);
2580}
2581
2582/*
2583 * Returns length of line (including trailing newline)
2584 * or negative on error.  'start' argument is updated to
2585 * point to first character of line.  This avoids copying
2586 * when possible.
2587 */
2588static ssize_t
2589readline(struct archive_read *a, struct tar *tar, const char **start,
2590    ssize_t limit, size_t *unconsumed)
2591{
2592	ssize_t bytes_read;
2593	ssize_t total_size = 0;
2594	const void *t;
2595	const char *s;
2596	void *p;
2597
2598	tar_flush_unconsumed(a, unconsumed);
2599
2600	t = __archive_read_ahead(a, 1, &bytes_read);
2601	if (bytes_read <= 0)
2602		return (ARCHIVE_FATAL);
2603	s = t;  /* Start of line? */
2604	p = memchr(t, '\n', bytes_read);
2605	/* If we found '\n' in the read buffer, return pointer to that. */
2606	if (p != NULL) {
2607		bytes_read = 1 + ((const char *)p) - s;
2608		if (bytes_read > limit) {
2609			archive_set_error(&a->archive,
2610			    ARCHIVE_ERRNO_FILE_FORMAT,
2611			    "Line too long");
2612			return (ARCHIVE_FATAL);
2613		}
2614		*unconsumed = bytes_read;
2615		*start = s;
2616		return (bytes_read);
2617	}
2618	*unconsumed = bytes_read;
2619	/* Otherwise, we need to accumulate in a line buffer. */
2620	for (;;) {
2621		if (total_size + bytes_read > limit) {
2622			archive_set_error(&a->archive,
2623			    ARCHIVE_ERRNO_FILE_FORMAT,
2624			    "Line too long");
2625			return (ARCHIVE_FATAL);
2626		}
2627		if (archive_string_ensure(&tar->line, total_size + bytes_read) == NULL) {
2628			archive_set_error(&a->archive, ENOMEM,
2629			    "Can't allocate working buffer");
2630			return (ARCHIVE_FATAL);
2631		}
2632		memcpy(tar->line.s + total_size, t, bytes_read);
2633		tar_flush_unconsumed(a, unconsumed);
2634		total_size += bytes_read;
2635		/* If we found '\n', clean up and return. */
2636		if (p != NULL) {
2637			*start = tar->line.s;
2638			return (total_size);
2639		}
2640		/* Read some more. */
2641		t = __archive_read_ahead(a, 1, &bytes_read);
2642		if (bytes_read <= 0)
2643			return (ARCHIVE_FATAL);
2644		s = t;  /* Start of line? */
2645		p = memchr(t, '\n', bytes_read);
2646		/* If we found '\n', trim the read. */
2647		if (p != NULL) {
2648			bytes_read = 1 + ((const char *)p) - s;
2649		}
2650		*unconsumed = bytes_read;
2651	}
2652}
2653
2654/*
2655 * base64_decode - Base64 decode
2656 *
2657 * This accepts most variations of base-64 encoding, including:
2658 *    * with or without line breaks
2659 *    * with or without the final group padded with '=' or '_' characters
2660 * (The most economical Base-64 variant does not pad the last group and
2661 * omits line breaks; RFC1341 used for MIME requires both.)
2662 */
2663static char *
2664base64_decode(const char *s, size_t len, size_t *out_len)
2665{
2666	static const unsigned char digits[64] = {
2667		'A','B','C','D','E','F','G','H','I','J','K','L','M','N',
2668		'O','P','Q','R','S','T','U','V','W','X','Y','Z','a','b',
2669		'c','d','e','f','g','h','i','j','k','l','m','n','o','p',
2670		'q','r','s','t','u','v','w','x','y','z','0','1','2','3',
2671		'4','5','6','7','8','9','+','/' };
2672	static unsigned char decode_table[128];
2673	char *out, *d;
2674	const unsigned char *src = (const unsigned char *)s;
2675
2676	/* If the decode table is not yet initialized, prepare it. */
2677	if (decode_table[digits[1]] != 1) {
2678		unsigned i;
2679		memset(decode_table, 0xff, sizeof(decode_table));
2680		for (i = 0; i < sizeof(digits); i++)
2681			decode_table[digits[i]] = i;
2682	}
2683
2684	/* Allocate enough space to hold the entire output. */
2685	/* Note that we may not use all of this... */
2686	out = (char *)malloc(len - len / 4 + 1);
2687	if (out == NULL) {
2688		*out_len = 0;
2689		return (NULL);
2690	}
2691	d = out;
2692
2693	while (len > 0) {
2694		/* Collect the next group of (up to) four characters. */
2695		int v = 0;
2696		int group_size = 0;
2697		while (group_size < 4 && len > 0) {
2698			/* '=' or '_' padding indicates final group. */
2699			if (*src == '=' || *src == '_') {
2700				len = 0;
2701				break;
2702			}
2703			/* Skip illegal characters (including line breaks) */
2704			if (*src > 127 || *src < 32
2705			    || decode_table[*src] == 0xff) {
2706				len--;
2707				src++;
2708				continue;
2709			}
2710			v <<= 6;
2711			v |= decode_table[*src++];
2712			len --;
2713			group_size++;
2714		}
2715		/* Align a short group properly. */
2716		v <<= 6 * (4 - group_size);
2717		/* Unpack the group we just collected. */
2718		switch (group_size) {
2719		case 4: d[2] = v & 0xff;
2720			/* FALLTHROUGH */
2721		case 3: d[1] = (v >> 8) & 0xff;
2722			/* FALLTHROUGH */
2723		case 2: d[0] = (v >> 16) & 0xff;
2724			break;
2725		case 1: /* this is invalid! */
2726			break;
2727		}
2728		d += group_size * 3 / 4;
2729	}
2730
2731	*out_len = d - out;
2732	return (out);
2733}
2734
2735static char *
2736url_decode(const char *in)
2737{
2738	char *out, *d;
2739	const char *s;
2740
2741	out = (char *)malloc(strlen(in) + 1);
2742	if (out == NULL)
2743		return (NULL);
2744	for (s = in, d = out; *s != '\0'; ) {
2745		if (s[0] == '%' && s[1] != '\0' && s[2] != '\0') {
2746			/* Try to convert % escape */
2747			int digit1 = tohex(s[1]);
2748			int digit2 = tohex(s[2]);
2749			if (digit1 >= 0 && digit2 >= 0) {
2750				/* Looks good, consume three chars */
2751				s += 3;
2752				/* Convert output */
2753				*d++ = ((digit1 << 4) | digit2);
2754				continue;
2755			}
2756			/* Else fall through and treat '%' as normal char */
2757		}
2758		*d++ = *s++;
2759	}
2760	*d = '\0';
2761	return (out);
2762}
2763
2764static int
2765tohex(int c)
2766{
2767	if (c >= '0' && c <= '9')
2768		return (c - '0');
2769	else if (c >= 'A' && c <= 'F')
2770		return (c - 'A' + 10);
2771	else if (c >= 'a' && c <= 'f')
2772		return (c - 'a' + 10);
2773	else
2774		return (-1);
2775}
2776