1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini tar implementation for busybox
4  *
5  * Modified to use common extraction code used by ar, cpio, dpkg-deb, dpkg
6  *  by Glenn McGrath
7  *
8  * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
9  * ground up.  It still has remnants of the old code lying about, but it is
10  * very different now (i.e., cleaner, less global variables, etc.)
11  *
12  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
13  *
14  * Based in part in the tar implementation in sash
15  *  Copyright (c) 1999 by David I. Bell
16  *  Permission is granted to use, distribute, or modify this source,
17  *  provided that this copyright notice remains intact.
18  *  Permission to distribute sash derived code under GPL has been granted.
19  *
20  * Based in part on the tar implementation from busybox-0.28
21  *  Copyright (C) 1995 Bruce Perens
22  *
23  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
24  */
25 /* TODO: security with -C DESTDIR option can be enhanced.
26  * Consider tar file created via:
27  * $ tar cvf bug.tar anything.txt
28  * $ ln -s /tmp symlink
29  * $ tar --append -f bug.tar symlink
30  * $ rm symlink
31  * $ mkdir symlink
32  * $ tar --append -f bug.tar symlink/evil.py
33  *
34  * This will result in an archive which contains:
35  * $ tar --list -f bug.tar
36  * anything.txt
37  * symlink
38  * symlink/evil.py
39  *
40  * Untarring it puts evil.py in '/tmp' even if the -C DESTDIR is given.
41  * This doesn't feel right, and IIRC GNU tar doesn't do that.
42  */
43 
44 //config:config TAR
45 //config:	bool "tar"
46 //config:	default y
47 //config:	help
48 //config:	  tar is an archiving program. It's commonly used with gzip to
49 //config:	  create compressed archives. It's probably the most widely used
50 //config:	  UNIX archive program.
51 //config:
52 //config:config FEATURE_TAR_CREATE
53 //config:	bool "Enable archive creation"
54 //config:	default y
55 //config:	depends on TAR
56 //config:	help
57 //config:	  If you enable this option you'll be able to create
58 //config:	  tar archives using the `-c' option.
59 //config:
60 //config:config FEATURE_TAR_AUTODETECT
61 //config:	bool "Autodetect compressed tarballs"
62 //config:	default y
63 //config:	depends on TAR && (FEATURE_SEAMLESS_Z || FEATURE_SEAMLESS_GZ || FEATURE_SEAMLESS_BZ2 || FEATURE_SEAMLESS_LZMA || FEATURE_SEAMLESS_XZ)
64 //config:	help
65 //config:	  With this option tar can automatically detect compressed
66 //config:	  tarballs. Currently it works only on files (not pipes etc).
67 //config:
68 //config:config FEATURE_TAR_FROM
69 //config:	bool "Enable -X (exclude from) and -T (include from) options)"
70 //config:	default y
71 //config:	depends on TAR
72 //config:	help
73 //config:	  If you enable this option you'll be able to specify
74 //config:	  a list of files to include or exclude from an archive.
75 //config:
76 //config:config FEATURE_TAR_OLDGNU_COMPATIBILITY
77 //config:	bool "Support for old tar header format"
78 //config:	default y
79 //config:	depends on TAR || DPKG
80 //config:	help
81 //config:	  This option is required to unpack archives created in
82 //config:	  the old GNU format; help to kill this old format by
83 //config:	  repacking your ancient archives with the new format.
84 //config:
85 //config:config FEATURE_TAR_OLDSUN_COMPATIBILITY
86 //config:	bool "Enable untarring of tarballs with checksums produced by buggy Sun tar"
87 //config:	default y
88 //config:	depends on TAR || DPKG
89 //config:	help
90 //config:	  This option is required to unpack archives created by some old
91 //config:	  version of Sun's tar (it was calculating checksum using signed
92 //config:	  arithmetic). It is said to be fixed in newer Sun tar, but "old"
93 //config:	  tarballs still exist.
94 //config:
95 //config:config FEATURE_TAR_GNU_EXTENSIONS
96 //config:	bool "Support for GNU tar extensions (long filenames)"
97 //config:	default y
98 //config:	depends on TAR || DPKG
99 //config:	help
100 //config:	  With this option busybox supports GNU long filenames and
101 //config:	  linknames.
102 //config:
103 //config:config FEATURE_TAR_LONG_OPTIONS
104 //config:	bool "Enable long options"
105 //config:	default y
106 //config:	depends on TAR && LONG_OPTS
107 //config:	help
108 //config:	  Enable use of long options, increases size by about 400 Bytes
109 //config:
110 //config:config FEATURE_TAR_TO_COMMAND
111 //config:	bool "Support for writing to an external program"
112 //config:	default y
113 //config:	depends on TAR && FEATURE_TAR_LONG_OPTIONS
114 //config:	help
115 //config:	  If you enable this option you'll be able to instruct tar to send
116 //config:	  the contents of each extracted file to the standard input of an
117 //config:	  external program.
118 //config:
119 //config:config FEATURE_TAR_UNAME_GNAME
120 //config:	bool "Enable use of user and group names"
121 //config:	default y
122 //config:	depends on TAR
123 //config:	help
124 //config:	  Enables use of user and group names in tar. This affects contents
125 //config:	  listings (-t) and preserving permissions when unpacking (-p).
126 //config:	  +200 bytes.
127 //config:
128 //config:config FEATURE_TAR_NOPRESERVE_TIME
129 //config:	bool "Enable -m (do not preserve time) option"
130 //config:	default y
131 //config:	depends on TAR
132 //config:	help
133 //config:	  With this option busybox supports GNU tar -m
134 //config:	  (do not preserve time) option.
135 //config:
136 //config:config FEATURE_TAR_SELINUX
137 //config:	bool "Support for extracting SELinux labels"
138 //config:	default n
139 //config:	depends on TAR && SELINUX
140 //config:	help
141 //config:	  With this option busybox supports restoring SELinux labels
142 //config:	  when extracting files from tar archives.
143 
144 //applet:IF_TAR(APPLET(tar, BB_DIR_BIN, BB_SUID_DROP))
145 //kbuild:lib-$(CONFIG_TAR) += tar.o
146 
147 #include <fnmatch.h>
148 #include "libbb.h"
149 #include "common_bufsiz.h"
150 #include "bb_archive.h"
151 /* FIXME: Stop using this non-standard feature */
152 #ifndef FNM_LEADING_DIR
153 # define FNM_LEADING_DIR 0
154 #endif
155 
156 #if 0
157 # define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
158 #else
159 # define DBG(...) ((void)0)
160 #endif
161 #define DBG_OPTION_PARSING 0
162 
163 
164 #define block_buf bb_common_bufsiz1
165 #define INIT_G() do { setup_common_bufsiz(); } while (0)
166 
167 
168 #if ENABLE_FEATURE_TAR_CREATE
169 
170 /*
171 ** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
172 ** the only functions that deal with the HardLinkInfo structure.
173 ** Even these functions use the xxxHardLinkInfo() functions.
174 */
175 typedef struct HardLinkInfo {
176 	struct HardLinkInfo *next; /* Next entry in list */
177 	dev_t dev;                 /* Device number */
178 	ino_t ino;                 /* Inode number */
179 //	short linkCount;           /* (Hard) Link Count */
180 	char name[1];              /* Start of filename (must be last) */
181 } HardLinkInfo;
182 
183 /* Some info to be carried along when creating a new tarball */
184 typedef struct TarBallInfo {
185 	int tarFd;                      /* Open-for-write file descriptor
186 	                                 * for the tarball */
187 	int verboseFlag;                /* Whether to print extra stuff or not */
188 	const llist_t *excludeList;     /* List of files to not include */
189 	HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
190 	HardLinkInfo *hlInfo;           /* Hard Link Info for the current file */
191 //TODO: save only st_dev + st_ino
192 	struct stat tarFileStatBuf;     /* Stat info for the tarball, letting
193 	                                 * us know the inode and device that the
194 	                                 * tarball lives, so we can avoid trying
195 	                                 * to include the tarball into itself */
196 } TarBallInfo;
197 
198 /* A nice enum with all the possible tar file content types */
199 enum {
200 	REGTYPE = '0',		/* regular file */
201 	REGTYPE0 = '\0',	/* regular file (ancient bug compat) */
202 	LNKTYPE = '1',		/* hard link */
203 	SYMTYPE = '2',		/* symbolic link */
204 	CHRTYPE = '3',		/* character special */
205 	BLKTYPE = '4',		/* block special */
206 	DIRTYPE = '5',		/* directory */
207 	FIFOTYPE = '6',		/* FIFO special */
208 	CONTTYPE = '7',		/* reserved */
209 	GNULONGLINK = 'K',	/* GNU long (>100 chars) link name */
210 	GNULONGNAME = 'L',	/* GNU long (>100 chars) file name */
211 };
212 
213 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,struct stat * statbuf,const char * fileName)214 static void addHardLinkInfo(HardLinkInfo **hlInfoHeadPtr,
215 					struct stat *statbuf,
216 					const char *fileName)
217 {
218 	/* Note: hlInfoHeadPtr can never be NULL! */
219 	HardLinkInfo *hlInfo;
220 
221 	hlInfo = xmalloc(sizeof(HardLinkInfo) + strlen(fileName));
222 	hlInfo->next = *hlInfoHeadPtr;
223 	*hlInfoHeadPtr = hlInfo;
224 	hlInfo->dev = statbuf->st_dev;
225 	hlInfo->ino = statbuf->st_ino;
226 //	hlInfo->linkCount = statbuf->st_nlink;
227 	strcpy(hlInfo->name, fileName);
228 }
229 
freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)230 static void freeHardLinkInfo(HardLinkInfo **hlInfoHeadPtr)
231 {
232 	HardLinkInfo *hlInfo;
233 	HardLinkInfo *hlInfoNext;
234 
235 	if (hlInfoHeadPtr) {
236 		hlInfo = *hlInfoHeadPtr;
237 		while (hlInfo) {
238 			hlInfoNext = hlInfo->next;
239 			free(hlInfo);
240 			hlInfo = hlInfoNext;
241 		}
242 		*hlInfoHeadPtr = NULL;
243 	}
244 }
245 
246 /* Might be faster (and bigger) if the dev/ino were stored in numeric order ;) */
findHardLinkInfo(HardLinkInfo * hlInfo,struct stat * statbuf)247 static HardLinkInfo *findHardLinkInfo(HardLinkInfo *hlInfo, struct stat *statbuf)
248 {
249 	while (hlInfo) {
250 		if (statbuf->st_ino == hlInfo->ino
251 		 && statbuf->st_dev == hlInfo->dev
252 		) {
253 			DBG("found hardlink:'%s'", hlInfo->name);
254 			break;
255 		}
256 		hlInfo = hlInfo->next;
257 	}
258 	return hlInfo;
259 }
260 
261 /* Put an octal string into the specified buffer.
262  * The number is zero padded and possibly null terminated.
263  * Stores low-order bits only if whole value does not fit. */
putOctal(char * cp,int len,off_t value)264 static void putOctal(char *cp, int len, off_t value)
265 {
266 	char tempBuffer[sizeof(off_t)*3 + 1];
267 	char *tempString = tempBuffer;
268 	int width;
269 
270 	width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
271 	tempString += (width - len);
272 
273 	/* If string has leading zeroes, we can drop one */
274 	/* and field will have trailing '\0' */
275 	/* (increases chances of compat with other tars) */
276 	if (tempString[0] == '0')
277 		tempString++;
278 
279 	/* Copy the string to the field */
280 	memcpy(cp, tempString, len);
281 }
282 #define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
283 
chksum_and_xwrite(int fd,struct tar_header_t * hp)284 static void chksum_and_xwrite(int fd, struct tar_header_t* hp)
285 {
286 	/* POSIX says that checksum is done on unsigned bytes
287 	 * (Sun and HP-UX gets it wrong... more details in
288 	 * GNU tar source) */
289 	const unsigned char *cp;
290 	int chksum, size;
291 
292 	strcpy(hp->magic, "ustar  ");
293 
294 	/* Calculate and store the checksum (i.e., the sum of all of the bytes of
295 	 * the header).  The checksum field must be filled with blanks for the
296 	 * calculation.  The checksum field is formatted differently from the
297 	 * other fields: it has 6 digits, a null, then a space -- rather than
298 	 * digits, followed by a null like the other fields... */
299 	memset(hp->chksum, ' ', sizeof(hp->chksum));
300 	cp = (const unsigned char *) hp;
301 	chksum = 0;
302 	size = sizeof(*hp);
303 	do { chksum += *cp++; } while (--size);
304 	putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);
305 
306 	/* Now write the header out to disk */
307 	xwrite(fd, hp, sizeof(*hp));
308 }
309 
310 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
writeLongname(int fd,int type,const char * name,int dir)311 static void writeLongname(int fd, int type, const char *name, int dir)
312 {
313 	static const struct {
314 		char mode[8];             /* 100-107 */
315 		char uid[8];              /* 108-115 */
316 		char gid[8];              /* 116-123 */
317 		char size[12];            /* 124-135 */
318 		char mtime[12];           /* 136-147 */
319 	} prefilled = {
320 		"0000000",
321 		"0000000",
322 		"0000000",
323 		"00000000000",
324 		"00000000000",
325 	};
326 	struct tar_header_t header;
327 	int size;
328 
329 	dir = !!dir; /* normalize: 0/1 */
330 	size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
331 	/* + dir: account for possible '/' */
332 
333 	memset(&header, 0, sizeof(header));
334 	strcpy(header.name, "././@LongLink");
335 	memcpy(header.mode, prefilled.mode, sizeof(prefilled));
336 	PUT_OCTAL(header.size, size);
337 	header.typeflag = type;
338 	chksum_and_xwrite(fd, &header);
339 
340 	/* Write filename[/] and pad the block. */
341 	/* dir=0: writes 'name<NUL>', pads */
342 	/* dir=1: writes 'name', writes '/<NUL>', pads */
343 	dir *= 2;
344 	xwrite(fd, name, size - dir);
345 	xwrite(fd, "/", dir);
346 	size = (-size) & (TAR_BLOCK_SIZE-1);
347 	memset(&header, 0, size);
348 	xwrite(fd, &header, size);
349 }
350 #endif
351 
352 /* Write out a tar header for the specified file/directory/whatever */
writeTarHeader(struct TarBallInfo * tbInfo,const char * header_name,const char * fileName,struct stat * statbuf)353 static int writeTarHeader(struct TarBallInfo *tbInfo,
354 		const char *header_name, const char *fileName, struct stat *statbuf)
355 {
356 	struct tar_header_t header;
357 
358 	memset(&header, 0, sizeof(header));
359 
360 	strncpy(header.name, header_name, sizeof(header.name));
361 
362 	/* POSIX says to mask mode with 07777. */
363 	PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
364 	PUT_OCTAL(header.uid, statbuf->st_uid);
365 	PUT_OCTAL(header.gid, statbuf->st_gid);
366 	memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
367 	/* users report that files with negative st_mtime cause trouble, so: */
368 	PUT_OCTAL(header.mtime, statbuf->st_mtime >= 0 ? statbuf->st_mtime : 0);
369 
370 	/* Enter the user and group names */
371 	safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
372 	safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
373 
374 	if (tbInfo->hlInfo) {
375 		/* This is a hard link */
376 		header.typeflag = LNKTYPE;
377 		strncpy(header.linkname, tbInfo->hlInfo->name,
378 				sizeof(header.linkname));
379 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
380 		/* Write out long linkname if needed */
381 		if (header.linkname[sizeof(header.linkname)-1])
382 			writeLongname(tbInfo->tarFd, GNULONGLINK,
383 					tbInfo->hlInfo->name, 0);
384 #endif
385 	} else if (S_ISLNK(statbuf->st_mode)) {
386 		char *lpath = xmalloc_readlink_or_warn(fileName);
387 		if (!lpath)
388 			return FALSE;
389 		header.typeflag = SYMTYPE;
390 		strncpy(header.linkname, lpath, sizeof(header.linkname));
391 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
392 		/* Write out long linkname if needed */
393 		if (header.linkname[sizeof(header.linkname)-1])
394 			writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
395 #else
396 		/* If it is larger than 100 bytes, bail out */
397 		if (header.linkname[sizeof(header.linkname)-1]) {
398 			free(lpath);
399 			bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
400 			return FALSE;
401 		}
402 #endif
403 		free(lpath);
404 	} else if (S_ISDIR(statbuf->st_mode)) {
405 		header.typeflag = DIRTYPE;
406 		/* Append '/' only if there is a space for it */
407 		if (!header.name[sizeof(header.name)-1])
408 			header.name[strlen(header.name)] = '/';
409 	} else if (S_ISCHR(statbuf->st_mode)) {
410 		header.typeflag = CHRTYPE;
411 		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
412 		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
413 	} else if (S_ISBLK(statbuf->st_mode)) {
414 		header.typeflag = BLKTYPE;
415 		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
416 		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
417 	} else if (S_ISFIFO(statbuf->st_mode)) {
418 		header.typeflag = FIFOTYPE;
419 	} else if (S_ISREG(statbuf->st_mode)) {
420 		/* header.size field is 12 bytes long */
421 		/* Does octal-encoded size fit? */
422 		uoff_t filesize = statbuf->st_size;
423 		if (sizeof(filesize) <= 4
424 		 || filesize <= (uoff_t)0777777777777LL
425 		) {
426 			PUT_OCTAL(header.size, filesize);
427 		}
428 		/* Does base256-encoded size fit?
429 		 * It always does unless off_t is wider than 64 bits.
430 		 */
431 		else if (ENABLE_FEATURE_TAR_GNU_EXTENSIONS
432 #if ULLONG_MAX > 0xffffffffffffffffLL /* 2^64-1 */
433 		 && (filesize <= 0x3fffffffffffffffffffffffLL)
434 #endif
435 		) {
436 			/* GNU tar uses "base-256 encoding" for very large numbers.
437 			 * Encoding is binary, with highest bit always set as a marker
438 			 * and sign in next-highest bit:
439 			 * 80 00 .. 00 - zero
440 			 * bf ff .. ff - largest positive number
441 			 * ff ff .. ff - minus 1
442 			 * c0 00 .. 00 - smallest negative number
443 			 */
444 			char *p8 = header.size + sizeof(header.size);
445 			do {
446 				*--p8 = (uint8_t)filesize;
447 				filesize >>= 8;
448 			} while (p8 != header.size);
449 			*p8 |= 0x80;
450 		} else {
451 			bb_error_msg_and_die("can't store file '%s' "
452 				"of size %"OFF_FMT"u, aborting",
453 				fileName, statbuf->st_size);
454 		}
455 		header.typeflag = REGTYPE;
456 	} else {
457 		bb_error_msg("%s: unknown file type", fileName);
458 		return FALSE;
459 	}
460 
461 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
462 	/* Write out long name if needed */
463 	/* (we, like GNU tar, output long linkname *before* long name) */
464 	if (header.name[sizeof(header.name)-1])
465 		writeLongname(tbInfo->tarFd, GNULONGNAME,
466 				header_name, S_ISDIR(statbuf->st_mode));
467 #endif
468 
469 	/* Now write the header out to disk */
470 	chksum_and_xwrite(tbInfo->tarFd, &header);
471 
472 	/* Now do the verbose thing (or not) */
473 	if (tbInfo->verboseFlag) {
474 		FILE *vbFd = stdout;
475 
476 		/* If archive goes to stdout, verbose goes to stderr */
477 		if (tbInfo->tarFd == STDOUT_FILENO)
478 			vbFd = stderr;
479 		/* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
480 		/* We don't have such excesses here: for us "v" == "vv" */
481 		/* '/' is probably a GNUism */
482 		fprintf(vbFd, "%s%s\n", header_name,
483 				S_ISDIR(statbuf->st_mode) ? "/" : "");
484 	}
485 
486 	return TRUE;
487 }
488 
489 #if ENABLE_FEATURE_TAR_FROM
exclude_file(const llist_t * excluded_files,const char * file)490 static int exclude_file(const llist_t *excluded_files, const char *file)
491 {
492 	while (excluded_files) {
493 		if (excluded_files->data[0] == '/') {
494 			if (fnmatch(excluded_files->data, file,
495 					FNM_PATHNAME | FNM_LEADING_DIR) == 0)
496 				return 1;
497 		} else {
498 			const char *p;
499 
500 			for (p = file; p[0] != '\0'; p++) {
501 				if ((p == file || p[-1] == '/')
502 				 && p[0] != '/'
503 				 && fnmatch(excluded_files->data, p,
504 						FNM_PATHNAME | FNM_LEADING_DIR) == 0
505 				) {
506 					return 1;
507 				}
508 			}
509 		}
510 		excluded_files = excluded_files->link;
511 	}
512 
513 	return 0;
514 }
515 #else
516 # define exclude_file(excluded_files, file) 0
517 #endif
518 
writeFileToTarball(const char * fileName,struct stat * statbuf,void * userData,int depth UNUSED_PARAM)519 static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statbuf,
520 			void *userData, int depth UNUSED_PARAM)
521 {
522 	struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
523 	const char *header_name;
524 	int inputFileFd = -1;
525 
526 	DBG("writeFileToTarball('%s')", fileName);
527 
528 	/* Strip leading '/' and such (must be before memorizing hardlink's name) */
529 	header_name = strip_unsafe_prefix(fileName);
530 
531 	if (header_name[0] == '\0')
532 		return TRUE;
533 
534 	/* It is against the rules to archive a socket */
535 	if (S_ISSOCK(statbuf->st_mode)) {
536 		bb_error_msg("%s: socket ignored", fileName);
537 		return TRUE;
538 	}
539 
540 	/*
541 	 * Check to see if we are dealing with a hard link.
542 	 * If so -
543 	 * Treat the first occurance of a given dev/inode as a file while
544 	 * treating any additional occurances as hard links.  This is done
545 	 * by adding the file information to the HardLinkInfo linked list.
546 	 */
547 	tbInfo->hlInfo = NULL;
548 	if (!S_ISDIR(statbuf->st_mode) && statbuf->st_nlink > 1) {
549 		DBG("'%s': st_nlink > 1", header_name);
550 		tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
551 		if (tbInfo->hlInfo == NULL) {
552 			DBG("'%s': addHardLinkInfo", header_name);
553 			addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, header_name);
554 		}
555 	}
556 
557 	/* It is a bad idea to store the archive we are in the process of creating,
558 	 * so check the device and inode to be sure that this particular file isn't
559 	 * the new tarball */
560 	if (tbInfo->tarFileStatBuf.st_dev == statbuf->st_dev
561 	 && tbInfo->tarFileStatBuf.st_ino == statbuf->st_ino
562 	) {
563 		bb_error_msg("%s: file is the archive; skipping", fileName);
564 		return TRUE;
565 	}
566 
567 	if (exclude_file(tbInfo->excludeList, header_name))
568 		return SKIP;
569 
570 #if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
571 	if (strlen(header_name) >= NAME_SIZE) {
572 		bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
573 		return TRUE;
574 	}
575 #endif
576 
577 	/* Is this a regular file? */
578 	if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
579 		/* open the file we want to archive, and make sure all is well */
580 		inputFileFd = open_or_warn(fileName, O_RDONLY);
581 		if (inputFileFd < 0) {
582 			return FALSE;
583 		}
584 	}
585 
586 	/* Add an entry to the tarball */
587 	if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
588 		return FALSE;
589 	}
590 
591 	/* If it was a regular file, write out the body */
592 	if (inputFileFd >= 0) {
593 		size_t readSize;
594 		/* Write the file to the archive. */
595 		/* We record size into header first, */
596 		/* and then write out file. If file shrinks in between, */
597 		/* tar will be corrupted. So we don't allow for that. */
598 		/* NB: GNU tar 1.16 warns and pads with zeroes */
599 		/* or even seeks back and updates header */
600 		bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
601 		////off_t readSize;
602 		////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
603 		////if (readSize != statbuf->st_size && readSize >= 0) {
604 		////	bb_error_msg_and_die("short read from %s, aborting", fileName);
605 		////}
606 
607 		/* Check that file did not grow in between? */
608 		/* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
609 
610 		close(inputFileFd);
611 
612 		/* Pad the file up to the tar block size */
613 		/* (a few tricks here in the name of code size) */
614 		readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
615 		memset(block_buf, 0, readSize);
616 		xwrite(tbInfo->tarFd, block_buf, readSize);
617 	}
618 
619 	return TRUE;
620 }
621 
622 #if SEAMLESS_COMPRESSION
623 /* Don't inline: vfork scares gcc and pessimizes code */
vfork_compressor(int tar_fd,const char * gzip)624 static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
625 {
626 	pid_t gzipPid;
627 
628 	// On Linux, vfork never unpauses parent early, although standard
629 	// allows for that. Do we want to waste bytes checking for it?
630 # define WAIT_FOR_CHILD 0
631 	volatile int vfork_exec_errno = 0;
632 	struct fd_pair gzipDataPipe;
633 # if WAIT_FOR_CHILD
634 	struct fd_pair gzipStatusPipe;
635 	xpiped_pair(gzipStatusPipe);
636 # endif
637 	xpiped_pair(gzipDataPipe);
638 
639 	signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
640 
641 	gzipPid = xvfork();
642 
643 	if (gzipPid == 0) {
644 		/* child */
645 		/* NB: close _first_, then move fds! */
646 		close(gzipDataPipe.wr);
647 # if WAIT_FOR_CHILD
648 		close(gzipStatusPipe.rd);
649 		/* gzipStatusPipe.wr will close only on exec -
650 		 * parent waits for this close to happen */
651 		fcntl(gzipStatusPipe.wr, F_SETFD, FD_CLOEXEC);
652 # endif
653 		xmove_fd(gzipDataPipe.rd, 0);
654 		xmove_fd(tar_fd, 1);
655 		/* exec gzip/bzip2 program/applet */
656 		BB_EXECLP(gzip, gzip, "-f", (char *)0);
657 		vfork_exec_errno = errno;
658 		_exit(EXIT_FAILURE);
659 	}
660 
661 	/* parent */
662 	xmove_fd(gzipDataPipe.wr, tar_fd);
663 	close(gzipDataPipe.rd);
664 # if WAIT_FOR_CHILD
665 	close(gzipStatusPipe.wr);
666 	while (1) {
667 		char buf;
668 		int n;
669 
670 		/* Wait until child execs (or fails to) */
671 		n = full_read(gzipStatusPipe.rd, &buf, 1);
672 		if (n < 0 /* && errno == EAGAIN */)
673 			continue;	/* try it again */
674 	}
675 	close(gzipStatusPipe.rd);
676 # endif
677 	if (vfork_exec_errno) {
678 		errno = vfork_exec_errno;
679 		bb_perror_msg_and_die("can't execute '%s'", gzip);
680 	}
681 }
682 #endif /* SEAMLESS_COMPRESSION */
683 
684 
685 #if !SEAMLESS_COMPRESSION
686 /* Do not pass gzip flag to writeTarFile() */
687 #define writeTarFile(tar_fd, verboseFlag, recurseFlags, include, exclude, gzip) \
688 	writeTarFile(tar_fd, verboseFlag, recurseFlags, include, exclude)
689 #endif
690 /* gcc 4.2.1 inlines it, making code bigger */
writeTarFile(int tar_fd,int verboseFlag,int recurseFlags,const llist_t * include,const llist_t * exclude,const char * gzip)691 static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
692 	int recurseFlags, const llist_t *include,
693 	const llist_t *exclude, const char *gzip)
694 {
695 	int errorFlag = FALSE;
696 	struct TarBallInfo tbInfo;
697 
698 	tbInfo.hlInfoHead = NULL;
699 	tbInfo.tarFd = tar_fd;
700 	tbInfo.verboseFlag = verboseFlag;
701 
702 	/* Store the stat info for the tarball's file, so
703 	 * can avoid including the tarball into itself....  */
704 	xfstat(tbInfo.tarFd, &tbInfo.tarFileStatBuf, "can't stat tar file");
705 
706 #if SEAMLESS_COMPRESSION
707 	if (gzip)
708 		vfork_compressor(tbInfo.tarFd, gzip);
709 #endif
710 
711 	tbInfo.excludeList = exclude;
712 
713 	/* Read the directory/files and iterate over them one at a time */
714 	while (include) {
715 		if (!recursive_action(include->data, recurseFlags,
716 				writeFileToTarball, writeFileToTarball, &tbInfo, 0)
717 		) {
718 			errorFlag = TRUE;
719 		}
720 		include = include->link;
721 	}
722 	/* Write two empty blocks to the end of the archive */
723 	memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
724 	xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
725 
726 	/* To be pedantically correct, we would check if the tarball
727 	 * is smaller than 20 tar blocks, and pad it if it was smaller,
728 	 * but that isn't necessary for GNU tar interoperability, and
729 	 * so is considered a waste of space */
730 
731 	/* Close so the child process (if any) will exit */
732 	close(tbInfo.tarFd);
733 
734 	/* Hang up the tools, close up shop, head home */
735 	if (ENABLE_FEATURE_CLEAN_UP)
736 		freeHardLinkInfo(&tbInfo.hlInfoHead);
737 
738 	if (errorFlag)
739 		bb_error_msg("error exit delayed from previous errors");
740 
741 #if SEAMLESS_COMPRESSION
742 	if (gzip) {
743 		int status;
744 		if (safe_waitpid(-1, &status, 0) == -1)
745 			bb_perror_msg("waitpid");
746 		else if (!WIFEXITED(status) || WEXITSTATUS(status))
747 			/* gzip was killed or has exited with nonzero! */
748 			errorFlag = TRUE;
749 	}
750 #endif
751 	return errorFlag;
752 }
753 #else /* !FEATURE_TAR_CREATE */
754 # define writeTarFile(...) 0
755 #endif
756 
757 #if ENABLE_FEATURE_TAR_FROM
append_file_list_to_list(llist_t * list)758 static llist_t *append_file_list_to_list(llist_t *list)
759 {
760 	FILE *src_stream;
761 	char *line;
762 	llist_t *newlist = NULL;
763 
764 	while (list) {
765 		src_stream = xfopen_stdin(llist_pop(&list));
766 		while ((line = xmalloc_fgetline(src_stream)) != NULL) {
767 			/* kill trailing '/' unless the string is just "/" */
768 			char *cp = last_char_is(line, '/');
769 			if (cp > line)
770 				*cp = '\0';
771 			llist_add_to_end(&newlist, line);
772 		}
773 		fclose(src_stream);
774 	}
775 	return newlist;
776 }
777 #endif
778 
779 //usage:#define tar_trivial_usage
780 //usage:	"-[" IF_FEATURE_TAR_CREATE("c") "xt"
781 //usage:	IF_FEATURE_SEAMLESS_Z("Z")
782 //usage:	IF_FEATURE_SEAMLESS_GZ("z")
783 //usage:	IF_FEATURE_SEAMLESS_XZ("J")
784 //usage:	IF_FEATURE_SEAMLESS_BZ2("j")
785 //usage:	IF_FEATURE_SEAMLESS_LZMA("a")
786 //usage:	IF_FEATURE_TAR_CREATE("h")
787 //usage:	IF_FEATURE_TAR_NOPRESERVE_TIME("m")
788 //usage:	"vO] "
789 //usage:	IF_FEATURE_TAR_FROM("[-X FILE] [-T FILE] ")
790 //usage:	"[-f TARFILE] [-C DIR] [FILE]..."
791 //usage:#define tar_full_usage "\n\n"
792 //usage:	IF_FEATURE_TAR_CREATE("Create, extract, ")
793 //usage:	IF_NOT_FEATURE_TAR_CREATE("Extract ")
794 //usage:	"or list files from a tar file\n"
795 //usage:     "\nOperation:"
796 //usage:	IF_FEATURE_TAR_CREATE(
797 //usage:     "\n	c	Create"
798 //usage:	)
799 //usage:     "\n	x	Extract"
800 //usage:     "\n	t	List"
801 //usage:     "\n	f	Name of TARFILE ('-' for stdin/out)"
802 //usage:     "\n	C	Change to DIR before operation"
803 //usage:     "\n	v	Verbose"
804 //usage:	IF_FEATURE_SEAMLESS_Z(
805 //usage:     "\n	Z	(De)compress using compress"
806 //usage:	)
807 //usage:	IF_FEATURE_SEAMLESS_GZ(
808 //usage:     "\n	z	(De)compress using gzip"
809 //usage:	)
810 //usage:	IF_FEATURE_SEAMLESS_XZ(
811 //usage:     "\n	J	(De)compress using xz"
812 //usage:	)
813 //usage:	IF_FEATURE_SEAMLESS_BZ2(
814 //usage:     "\n	j	(De)compress using bzip2"
815 //usage:	)
816 //usage:	IF_FEATURE_SEAMLESS_LZMA(
817 //usage:     "\n	a	(De)compress using lzma"
818 //usage:	)
819 //usage:     "\n	O	Extract to stdout"
820 //usage:	IF_FEATURE_TAR_CREATE(
821 //usage:     "\n	h	Follow symlinks"
822 //usage:	)
823 //usage:	IF_FEATURE_TAR_NOPRESERVE_TIME(
824 //usage:     "\n	m	Don't restore mtime"
825 //usage:	)
826 //usage:	IF_FEATURE_TAR_FROM(
827 //usage:	IF_FEATURE_TAR_LONG_OPTIONS(
828 //usage:     "\n	exclude	File to exclude"
829 //usage:	)
830 //usage:     "\n	X	File with names to exclude"
831 //usage:     "\n	T	File with names to include"
832 //usage:	)
833 //usage:
834 //usage:#define tar_example_usage
835 //usage:       "$ zcat /tmp/tarball.tar.gz | tar -xf -\n"
836 //usage:       "$ tar -cf /tmp/tarball.tar /usr/local\n"
837 
838 // Supported but aren't in --help:
839 //	o	no-same-owner
840 //	p	same-permissions
841 //	k	keep-old
842 //	no-recursion
843 //	numeric-owner
844 //	no-same-permissions
845 //	overwrite
846 //IF_FEATURE_TAR_TO_COMMAND(
847 //	to-command
848 //)
849 
850 enum {
851 	OPTBIT_KEEP_OLD = 8,
852 	IF_FEATURE_TAR_CREATE(   OPTBIT_CREATE      ,)
853 	IF_FEATURE_TAR_CREATE(   OPTBIT_DEREFERENCE ,)
854 	IF_FEATURE_SEAMLESS_BZ2( OPTBIT_BZIP2       ,)
855 	IF_FEATURE_SEAMLESS_LZMA(OPTBIT_LZMA        ,)
856 	IF_FEATURE_TAR_FROM(     OPTBIT_INCLUDE_FROM,)
857 	IF_FEATURE_TAR_FROM(     OPTBIT_EXCLUDE_FROM,)
858 	IF_FEATURE_SEAMLESS_GZ(  OPTBIT_GZIP        ,)
859 	IF_FEATURE_SEAMLESS_XZ(  OPTBIT_XZ          ,) // 16th bit
860 	IF_FEATURE_SEAMLESS_Z(   OPTBIT_COMPRESS    ,)
861 	IF_FEATURE_TAR_NOPRESERVE_TIME(OPTBIT_NOPRESERVE_TIME,)
862 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
863 	OPTBIT_STRIP_COMPONENTS,
864 	OPTBIT_NORECURSION,
865 	IF_FEATURE_TAR_TO_COMMAND(OPTBIT_2COMMAND   ,)
866 	OPTBIT_NUMERIC_OWNER,
867 	OPTBIT_NOPRESERVE_PERM,
868 	OPTBIT_OVERWRITE,
869 #endif
870 	OPT_TEST         = 1 << 0, // t
871 	OPT_EXTRACT      = 1 << 1, // x
872 	OPT_BASEDIR      = 1 << 2, // C
873 	OPT_TARNAME      = 1 << 3, // f
874 	OPT_2STDOUT      = 1 << 4, // O
875 	OPT_NOPRESERVE_OWNER = 1 << 5, // o == no-same-owner
876 	OPT_P            = 1 << 6, // p
877 	OPT_VERBOSE      = 1 << 7, // v
878 	OPT_KEEP_OLD     = 1 << 8, // k
879 	OPT_CREATE       = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_CREATE      )) + 0, // c
880 	OPT_DEREFERENCE  = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_DEREFERENCE )) + 0, // h
881 	OPT_BZIP2        = IF_FEATURE_SEAMLESS_BZ2( (1 << OPTBIT_BZIP2       )) + 0, // j
882 	OPT_LZMA         = IF_FEATURE_SEAMLESS_LZMA((1 << OPTBIT_LZMA        )) + 0, // a
883 	OPT_INCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_INCLUDE_FROM)) + 0, // T
884 	OPT_EXCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_EXCLUDE_FROM)) + 0, // X
885 	OPT_GZIP         = IF_FEATURE_SEAMLESS_GZ(  (1 << OPTBIT_GZIP        )) + 0, // z
886 	OPT_XZ           = IF_FEATURE_SEAMLESS_XZ(  (1 << OPTBIT_XZ          )) + 0, // J
887 	OPT_COMPRESS     = IF_FEATURE_SEAMLESS_Z(   (1 << OPTBIT_COMPRESS    )) + 0, // Z
888 	OPT_NOPRESERVE_TIME  = IF_FEATURE_TAR_NOPRESERVE_TIME((1 << OPTBIT_NOPRESERVE_TIME)) + 0, // m
889 	OPT_STRIP_COMPONENTS = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_STRIP_COMPONENTS)) + 0, // strip-components
890 	OPT_NORECURSION      = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NORECURSION    )) + 0, // no-recursion
891 	OPT_2COMMAND         = IF_FEATURE_TAR_TO_COMMAND(  (1 << OPTBIT_2COMMAND       )) + 0, // to-command
892 	OPT_NUMERIC_OWNER    = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NUMERIC_OWNER  )) + 0, // numeric-owner
893 	OPT_NOPRESERVE_PERM  = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOPRESERVE_PERM)) + 0, // no-same-permissions
894 	OPT_OVERWRITE        = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_OVERWRITE      )) + 0, // overwrite
895 
896 	OPT_ANY_COMPRESS = (OPT_BZIP2 | OPT_LZMA | OPT_GZIP | OPT_XZ | OPT_COMPRESS),
897 };
898 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
899 static const char tar_longopts[] ALIGN1 =
900 	"list\0"                No_argument       "t"
901 	"extract\0"             No_argument       "x"
902 	"directory\0"           Required_argument "C"
903 	"file\0"                Required_argument "f"
904 	"to-stdout\0"           No_argument       "O"
905 	/* do not restore owner */
906 	/* Note: GNU tar handles 'o' as no-same-owner only on extract,
907 	 * on create, 'o' is --old-archive. We do not support --old-archive. */
908 	"no-same-owner\0"       No_argument       "o"
909 	"same-permissions\0"    No_argument       "p"
910 	"verbose\0"             No_argument       "v"
911 	"keep-old\0"            No_argument       "k"
912 # if ENABLE_FEATURE_TAR_CREATE
913 	"create\0"              No_argument       "c"
914 	"dereference\0"         No_argument       "h"
915 # endif
916 # if ENABLE_FEATURE_SEAMLESS_BZ2
917 	"bzip2\0"               No_argument       "j"
918 # endif
919 # if ENABLE_FEATURE_SEAMLESS_LZMA
920 	"lzma\0"                No_argument       "a"
921 # endif
922 # if ENABLE_FEATURE_TAR_FROM
923 	"files-from\0"          Required_argument "T"
924 	"exclude-from\0"        Required_argument "X"
925 # endif
926 # if ENABLE_FEATURE_SEAMLESS_GZ
927 	"gzip\0"                No_argument       "z"
928 # endif
929 # if ENABLE_FEATURE_SEAMLESS_XZ
930 	"xz\0"                  No_argument       "J"
931 # endif
932 # if ENABLE_FEATURE_SEAMLESS_Z
933 	"compress\0"            No_argument       "Z"
934 # endif
935 # if ENABLE_FEATURE_TAR_NOPRESERVE_TIME
936 	"touch\0"               No_argument       "m"
937 # endif
938 	"strip-components\0"	Required_argument "\xf9"
939 	"no-recursion\0"	No_argument       "\xfa"
940 # if ENABLE_FEATURE_TAR_TO_COMMAND
941 	"to-command\0"		Required_argument "\xfb"
942 # endif
943 	/* use numeric uid/gid from tar header, not textual */
944 	"numeric-owner\0"       No_argument       "\xfc"
945 	/* do not restore mode */
946 	"no-same-permissions\0" No_argument       "\xfd"
947 	/* on unpack, open with O_TRUNC and !O_EXCL */
948 	"overwrite\0"           No_argument       "\xfe"
949 	/* --exclude takes next bit position in option mask, */
950 	/* therefore we have to put it _after_ --no-same-permissions */
951 # if ENABLE_FEATURE_TAR_FROM
952 	"exclude\0"             Required_argument "\xff"
953 # endif
954 	;
955 #endif
956 
957 int tar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
tar_main(int argc UNUSED_PARAM,char ** argv)958 int tar_main(int argc UNUSED_PARAM, char **argv)
959 {
960 	archive_handle_t *tar_handle;
961 	char *base_dir = NULL;
962 	const char *tar_filename = "-";
963 	unsigned opt;
964 	int verboseFlag = 0;
965 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
966 	llist_t *excludes = NULL;
967 #endif
968 	INIT_G();
969 
970 	/* Initialise default values */
971 	tar_handle = init_handle();
972 	tar_handle->ah_flags = ARCHIVE_CREATE_LEADING_DIRS
973 	                     | ARCHIVE_RESTORE_DATE
974 	                     | ARCHIVE_UNLINK_OLD;
975 
976 	/* Apparently only root's tar preserves perms (see bug 3844) */
977 	if (getuid() != 0)
978 		tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
979 
980 	/* Prepend '-' to the first argument if required */
981 	opt_complementary = "--:" // first arg is options
982 		"tt:vv:" // count -t,-v
983 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
984 		"\xff::" // --exclude=PATTERN is a list
985 #endif
986 		IF_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
987 		IF_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
988 		IF_NOT_FEATURE_TAR_CREATE("t--x:x--t") // mutually exclusive
989 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
990 		":\xf9+" // --strip-components=NUM
991 #endif
992 	;
993 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
994 	applet_long_options = tar_longopts;
995 #endif
996 #if ENABLE_DESKTOP
997 	/* Lie to buildroot when it starts asking stupid questions. */
998 	if (argv[1] && strcmp(argv[1], "--version") == 0) {
999 		// Output of 'tar --version' examples:
1000 		// tar (GNU tar) 1.15.1
1001 		// tar (GNU tar) 1.25
1002 		// bsdtar 2.8.3 - libarchive 2.8.3
1003 		puts("tar (busybox) " BB_VER);
1004 		return 0;
1005 	}
1006 	if (argv[1] && argv[1][0] != '-') {
1007 		/* Compat:
1008 		 * 1st argument without dash handles options with parameters
1009 		 * differently from dashed one: it takes *next argv[i]*
1010 		 * as paramenter even if there are more chars in 1st argument:
1011 		 *  "tar fx TARFILE" - "x" is not taken as f's param
1012 		 *  but is interpreted as -x option
1013 		 *  "tar -xf TARFILE" - dashed equivalent of the above
1014 		 *  "tar -fx ..." - "x" is taken as f's param
1015 		 * getopt32 wouldn't handle 1st command correctly.
1016 		 * Unfortunately, people do use such commands.
1017 		 * We massage argv[1] to work around it by moving 'f'
1018 		 * to the end of the string.
1019 		 * More contrived "tar fCx TARFILE DIR" still fails,
1020 		 * but such commands are much less likely to be used.
1021 		 */
1022 		char *f = strchr(argv[1], 'f');
1023 		if (f) {
1024 			while (f[1] != '\0') {
1025 				*f = f[1];
1026 				f++;
1027 			}
1028 			*f = 'f';
1029 		}
1030 	}
1031 #endif
1032 	opt = getopt32(argv,
1033 		"txC:f:Oopvk"
1034 		IF_FEATURE_TAR_CREATE(   "ch"    )
1035 		IF_FEATURE_SEAMLESS_BZ2( "j"     )
1036 		IF_FEATURE_SEAMLESS_LZMA("a"     )
1037 		IF_FEATURE_TAR_FROM(     "T:*X:*")
1038 		IF_FEATURE_SEAMLESS_GZ(  "z"     )
1039 		IF_FEATURE_SEAMLESS_XZ(  "J"     )
1040 		IF_FEATURE_SEAMLESS_Z(   "Z"     )
1041 		IF_FEATURE_TAR_NOPRESERVE_TIME("m")
1042 		IF_FEATURE_TAR_LONG_OPTIONS("\xf9:") // --strip-components
1043 		, &base_dir // -C dir
1044 		, &tar_filename // -f filename
1045 		IF_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
1046 		IF_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
1047 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
1048 		, &tar_handle->tar__strip_components // --strip-components
1049 #endif
1050 		IF_FEATURE_TAR_TO_COMMAND(, &(tar_handle->tar__to_command)) // --to-command
1051 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
1052 		, &excludes // --exclude
1053 #endif
1054 		, &verboseFlag // combined count for -t and -v
1055 		, &verboseFlag // combined count for -t and -v
1056 		);
1057 #if DBG_OPTION_PARSING
1058 	bb_error_msg("opt: 0x%08x", opt);
1059 # define showopt(o) bb_error_msg("opt & %s(%x): %x", #o, o, opt & o);
1060 	showopt(OPT_TEST            );
1061 	showopt(OPT_EXTRACT         );
1062 	showopt(OPT_BASEDIR         );
1063 	showopt(OPT_TARNAME         );
1064 	showopt(OPT_2STDOUT         );
1065 	showopt(OPT_NOPRESERVE_OWNER);
1066 	showopt(OPT_P               );
1067 	showopt(OPT_VERBOSE         );
1068 	showopt(OPT_KEEP_OLD        );
1069 	showopt(OPT_CREATE          );
1070 	showopt(OPT_DEREFERENCE     );
1071 	showopt(OPT_BZIP2           );
1072 	showopt(OPT_LZMA            );
1073 	showopt(OPT_INCLUDE_FROM    );
1074 	showopt(OPT_EXCLUDE_FROM    );
1075 	showopt(OPT_GZIP            );
1076 	showopt(OPT_XZ              );
1077 	showopt(OPT_COMPRESS        );
1078 	showopt(OPT_NOPRESERVE_TIME );
1079 	showopt(OPT_STRIP_COMPONENTS);
1080 	showopt(OPT_NORECURSION     );
1081 	showopt(OPT_2COMMAND        );
1082 	showopt(OPT_NUMERIC_OWNER   );
1083 	showopt(OPT_NOPRESERVE_PERM );
1084 	showopt(OPT_OVERWRITE       );
1085 	showopt(OPT_ANY_COMPRESS    );
1086 	bb_error_msg("base_dir:'%s'", base_dir);
1087 	bb_error_msg("tar_filename:'%s'", tar_filename);
1088 	bb_error_msg("verboseFlag:%d", verboseFlag);
1089 	bb_error_msg("tar_handle->tar__to_command:'%s'", tar_handle->tar__to_command);
1090 	bb_error_msg("tar_handle->tar__strip_components:%u", tar_handle->tar__strip_components);
1091 	return 0;
1092 # undef showopt
1093 #endif
1094 	argv += optind;
1095 
1096 	if (verboseFlag)
1097 		tar_handle->action_header = header_verbose_list;
1098 	if (verboseFlag == 1)
1099 		tar_handle->action_header = header_list;
1100 
1101 	if (opt & OPT_EXTRACT)
1102 		tar_handle->action_data = data_extract_all;
1103 
1104 	if (opt & OPT_2STDOUT)
1105 		tar_handle->action_data = data_extract_to_stdout;
1106 
1107 	if (opt & OPT_2COMMAND) {
1108 		putenv((char*)"TAR_FILETYPE=f");
1109 		signal(SIGPIPE, SIG_IGN);
1110 		tar_handle->action_data = data_extract_to_command;
1111 		IF_FEATURE_TAR_TO_COMMAND(tar_handle->tar__to_command_shell = xstrdup(get_shell_name());)
1112 	}
1113 
1114 	if (opt & OPT_KEEP_OLD)
1115 		tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
1116 
1117 	if (opt & OPT_NUMERIC_OWNER)
1118 		tar_handle->ah_flags |= ARCHIVE_NUMERIC_OWNER;
1119 
1120 	if (opt & OPT_NOPRESERVE_OWNER)
1121 		tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_OWNER;
1122 
1123 	if (opt & OPT_NOPRESERVE_PERM)
1124 		tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
1125 
1126 	if (opt & OPT_OVERWRITE) {
1127 		tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
1128 		tar_handle->ah_flags |= ARCHIVE_O_TRUNC;
1129 	}
1130 
1131 	if (opt & OPT_NOPRESERVE_TIME)
1132 		tar_handle->ah_flags &= ~ARCHIVE_RESTORE_DATE;
1133 
1134 #if ENABLE_FEATURE_TAR_FROM
1135 	tar_handle->reject = append_file_list_to_list(tar_handle->reject);
1136 # if ENABLE_FEATURE_TAR_LONG_OPTIONS
1137 	/* Append excludes to reject */
1138 	while (excludes) {
1139 		llist_t *next = excludes->link;
1140 		excludes->link = tar_handle->reject;
1141 		tar_handle->reject = excludes;
1142 		excludes = next;
1143 	}
1144 # endif
1145 	tar_handle->accept = append_file_list_to_list(tar_handle->accept);
1146 #endif
1147 
1148 	/* Setup an array of filenames to work with */
1149 	/* TODO: This is the same as in ar, make a separate function? */
1150 	while (*argv) {
1151 		/* kill trailing '/' unless the string is just "/" */
1152 		char *cp = last_char_is(*argv, '/');
1153 		if (cp > *argv)
1154 			*cp = '\0';
1155 		llist_add_to_end(&tar_handle->accept, *argv);
1156 		argv++;
1157 	}
1158 
1159 	if (tar_handle->accept || tar_handle->reject)
1160 		tar_handle->filter = filter_accept_reject_list;
1161 
1162 	/* Open the tar file */
1163 	{
1164 		int tar_fd = STDIN_FILENO;
1165 		int flags = O_RDONLY;
1166 
1167 		if (opt & OPT_CREATE) {
1168 			/* Make sure there is at least one file to tar up */
1169 			if (tar_handle->accept == NULL)
1170 				bb_error_msg_and_die("empty archive");
1171 
1172 			tar_fd = STDOUT_FILENO;
1173 			/* Mimicking GNU tar 1.15.1: */
1174 			flags = O_WRONLY | O_CREAT | O_TRUNC;
1175 		}
1176 
1177 		if (LONE_DASH(tar_filename)) {
1178 			tar_handle->src_fd = tar_fd;
1179 			tar_handle->seek = seek_by_read;
1180 		} else {
1181 			if (ENABLE_FEATURE_TAR_AUTODETECT
1182 			 && flags == O_RDONLY
1183 			 && !(opt & OPT_ANY_COMPRESS)
1184 			) {
1185 				tar_handle->src_fd = open_zipped(tar_filename, /*fail_if_not_compressed:*/ 0);
1186 				if (tar_handle->src_fd < 0)
1187 					bb_perror_msg_and_die("can't open '%s'", tar_filename);
1188 			} else {
1189 				tar_handle->src_fd = xopen(tar_filename, flags);
1190 			}
1191 		}
1192 	}
1193 
1194 	if (base_dir)
1195 		xchdir(base_dir);
1196 
1197 	//if (SEAMLESS_COMPRESSION)
1198 	//	/* We need to know whether child (gzip/bzip/etc) exits abnormally */
1199 	//	signal(SIGCHLD, check_errors_in_children);
1200 
1201 #if ENABLE_FEATURE_TAR_CREATE
1202 	/* Create an archive */
1203 	if (opt & OPT_CREATE) {
1204 # if SEAMLESS_COMPRESSION
1205 		const char *zipMode = NULL;
1206 		if (opt & OPT_COMPRESS)
1207 			zipMode = "compress";
1208 		if (opt & OPT_GZIP)
1209 			zipMode = "gzip";
1210 		if (opt & OPT_BZIP2)
1211 			zipMode = "bzip2";
1212 		if (opt & OPT_LZMA)
1213 			zipMode = "lzma";
1214 		if (opt & OPT_XZ)
1215 			zipMode = "xz";
1216 # endif
1217 		/* NB: writeTarFile() closes tar_handle->src_fd */
1218 		return writeTarFile(tar_handle->src_fd, verboseFlag,
1219 				(opt & OPT_DEREFERENCE ? ACTION_FOLLOWLINKS : 0)
1220 				| (opt & OPT_NORECURSION ? 0 : ACTION_RECURSE),
1221 				tar_handle->accept,
1222 				tar_handle->reject, zipMode);
1223 	}
1224 #endif
1225 
1226 	if (opt & OPT_ANY_COMPRESS) {
1227 		USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_state_t *xstate);)
1228 		USE_FOR_NOMMU(const char *xformer_prog;)
1229 
1230 		if (opt & OPT_COMPRESS)
1231 			USE_FOR_MMU(xformer = unpack_Z_stream;)
1232 			USE_FOR_NOMMU(xformer_prog = "uncompress";)
1233 		if (opt & OPT_GZIP)
1234 			USE_FOR_MMU(xformer = unpack_gz_stream;)
1235 			USE_FOR_NOMMU(xformer_prog = "gunzip";)
1236 		if (opt & OPT_BZIP2)
1237 			USE_FOR_MMU(xformer = unpack_bz2_stream;)
1238 			USE_FOR_NOMMU(xformer_prog = "bunzip2";)
1239 		if (opt & OPT_LZMA)
1240 			USE_FOR_MMU(xformer = unpack_lzma_stream;)
1241 			USE_FOR_NOMMU(xformer_prog = "unlzma";)
1242 		if (opt & OPT_XZ)
1243 			USE_FOR_MMU(xformer = unpack_xz_stream;)
1244 			USE_FOR_NOMMU(xformer_prog = "unxz";)
1245 
1246 		fork_transformer_with_sig(tar_handle->src_fd, xformer, xformer_prog);
1247 		/* Can't lseek over pipes */
1248 		tar_handle->seek = seek_by_read;
1249 		/*tar_handle->offset = 0; - already is */
1250 	}
1251 
1252 	/* Zero processed headers (== empty file) is not a valid tarball.
1253 	 * We (ab)use bb_got_signal as exitcode here,
1254 	 * because check_errors_in_children() uses _it_ as error indicator.
1255 	 */
1256 	bb_got_signal = EXIT_FAILURE;
1257 
1258 	while (get_header_tar(tar_handle) == EXIT_SUCCESS)
1259 		bb_got_signal = EXIT_SUCCESS; /* saw at least one header, good */
1260 
1261 	/* Check that every file that should have been extracted was */
1262 	while (tar_handle->accept) {
1263 		if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
1264 		 && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
1265 		) {
1266 			bb_error_msg_and_die("%s: not found in archive",
1267 				tar_handle->accept->data);
1268 		}
1269 		tar_handle->accept = tar_handle->accept->link;
1270 	}
1271 	if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
1272 		close(tar_handle->src_fd);
1273 
1274 	if (SEAMLESS_COMPRESSION || OPT_COMPRESS) {
1275 		/* Set bb_got_signal to 1 if a child died with !0 exitcode */
1276 		check_errors_in_children(0);
1277 	}
1278 
1279 	return bb_got_signal;
1280 }
1281