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 *  Glenn McGrath <bug1@iinet.net.au>
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 the 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 tarball for details.
24 */
25
26#include <fnmatch.h>
27#include <getopt.h>
28#include "libbb.h"
29#include "unarchive.h"
30
31#define block_buf bb_common_bufsiz1
32
33#if ENABLE_FEATURE_TAR_CREATE
34
35/* Tar file constants  */
36
37#define TAR_BLOCK_SIZE		512
38
39/* POSIX tar Header Block, from POSIX 1003.1-1990  */
40#define NAME_SIZE      100
41#define NAME_SIZE_STR "100"
42typedef struct TarHeader TarHeader;
43struct TarHeader {		  /* byte offset */
44	char name[NAME_SIZE];     /*   0-99 */
45	char mode[8];             /* 100-107 */
46	char uid[8];              /* 108-115 */
47	char gid[8];              /* 116-123 */
48	char size[12];            /* 124-135 */
49	char mtime[12];           /* 136-147 */
50	char chksum[8];           /* 148-155 */
51	char typeflag;            /* 156-156 */
52	char linkname[NAME_SIZE]; /* 157-256 */
53	char magic[6];            /* 257-262 */
54	char version[2];          /* 263-264 */
55	char uname[32];           /* 265-296 */
56	char gname[32];           /* 297-328 */
57	char devmajor[8];         /* 329-336 */
58	char devminor[8];         /* 337-344 */
59	char prefix[155];         /* 345-499 */
60	char padding[12];         /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
61};
62
63/*
64** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
65** the only functions that deal with the HardLinkInfo structure.
66** Even these functions use the xxxHardLinkInfo() functions.
67*/
68typedef struct HardLinkInfo HardLinkInfo;
69struct HardLinkInfo {
70	HardLinkInfo *next;	/* Next entry in list */
71	dev_t dev;			/* Device number */
72	ino_t ino;			/* Inode number */
73	short linkCount;	/* (Hard) Link Count */
74	char name[1];		/* Start of filename (must be last) */
75};
76
77/* Some info to be carried along when creating a new tarball */
78typedef struct TarBallInfo TarBallInfo;
79struct TarBallInfo {
80	int tarFd;				/* Open-for-write file descriptor
81							   for the tarball */
82	struct stat statBuf;	/* Stat info for the tarball, letting
83							   us know the inode and device that the
84							   tarball lives, so we can avoid trying
85							   to include the tarball into itself */
86	int verboseFlag;		/* Whether to print extra stuff or not */
87	const llist_t *excludeList;	/* List of files to not include */
88	HardLinkInfo *hlInfoHead;	/* Hard Link Tracking Information */
89	HardLinkInfo *hlInfo;	/* Hard Link Info for the current file */
90};
91
92/* A nice enum with all the possible tar file content types */
93enum TarFileType {
94	REGTYPE = '0',		/* regular file */
95	REGTYPE0 = '\0',	/* regular file (ancient bug compat) */
96	LNKTYPE = '1',		/* hard link */
97	SYMTYPE = '2',		/* symbolic link */
98	CHRTYPE = '3',		/* character special */
99	BLKTYPE = '4',		/* block special */
100	DIRTYPE = '5',		/* directory */
101	FIFOTYPE = '6',		/* FIFO special */
102	CONTTYPE = '7',		/* reserved */
103	GNULONGLINK = 'K',	/* GNU long (>100 chars) link name */
104	GNULONGNAME = 'L',	/* GNU long (>100 chars) file name */
105};
106typedef enum TarFileType TarFileType;
107
108/* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
109static void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
110					struct stat *statbuf,
111					const char *fileName)
112{
113	/* Note: hlInfoHeadPtr can never be NULL! */
114	HardLinkInfo *hlInfo;
115
116	hlInfo = xmalloc(sizeof(HardLinkInfo) + strlen(fileName));
117	hlInfo->next = *hlInfoHeadPtr;
118	*hlInfoHeadPtr = hlInfo;
119	hlInfo->dev = statbuf->st_dev;
120	hlInfo->ino = statbuf->st_ino;
121	hlInfo->linkCount = statbuf->st_nlink;
122	strcpy(hlInfo->name, fileName);
123}
124
125static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
126{
127	HardLinkInfo *hlInfo;
128	HardLinkInfo *hlInfoNext;
129
130	if (hlInfoHeadPtr) {
131		hlInfo = *hlInfoHeadPtr;
132		while (hlInfo) {
133			hlInfoNext = hlInfo->next;
134			free(hlInfo);
135			hlInfo = hlInfoNext;
136		}
137		*hlInfoHeadPtr = NULL;
138	}
139}
140
141/* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
142static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbuf)
143{
144	while (hlInfo) {
145		if ((statbuf->st_ino == hlInfo->ino) && (statbuf->st_dev == hlInfo->dev))
146			break;
147		hlInfo = hlInfo->next;
148	}
149	return hlInfo;
150}
151
152/* Put an octal string into the specified buffer.
153 * The number is zero padded and possibly null terminated.
154 * Stores low-order bits only if whole value does not fit. */
155static void putOctal(char *cp, int len, off_t value)
156{
157	char tempBuffer[sizeof(off_t)*3+1];
158	char *tempString = tempBuffer;
159	int width;
160
161	width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
162	tempString += (width - len);
163
164	/* If string has leading zeroes, we can drop one */
165	/* and field will have trailing '\0' */
166	/* (increases chances of compat with other tars) */
167	if (tempString[0] == '0')
168		tempString++;
169
170	/* Copy the string to the field */
171	memcpy(cp, tempString, len);
172}
173#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
174
175static void chksum_and_xwrite(int fd, struct TarHeader* hp)
176{
177	/* POSIX says that checksum is done on unsigned bytes
178	 * (Sun and HP-UX gets it wrong... more details in
179	 * GNU tar source) */
180	const unsigned char *cp;
181	int chksum, size;
182
183	strcpy(hp->magic, "ustar  ");
184
185	/* Calculate and store the checksum (i.e., the sum of all of the bytes of
186	 * the header).  The checksum field must be filled with blanks for the
187	 * calculation.  The checksum field is formatted differently from the
188	 * other fields: it has 6 digits, a null, then a space -- rather than
189	 * digits, followed by a null like the other fields... */
190	memset(hp->chksum, ' ', sizeof(hp->chksum));
191	cp = (const unsigned char *) hp;
192	chksum = 0;
193	size = sizeof(*hp);
194	do { chksum += *cp++; } while (--size);
195	putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);
196
197	/* Now write the header out to disk */
198	xwrite(fd, hp, sizeof(*hp));
199}
200
201#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
202static void writeLongname(int fd, int type, const char *name, int dir)
203{
204	static const struct {
205		char mode[8];             /* 100-107 */
206		char uid[8];              /* 108-115 */
207		char gid[8];              /* 116-123 */
208		char size[12];            /* 124-135 */
209		char mtime[12];           /* 136-147 */
210	} prefilled = {
211		"0000000",
212		"0000000",
213		"0000000",
214		"00000000000",
215		"00000000000",
216	};
217	struct TarHeader header;
218	int size;
219
220	dir = !!dir; /* normalize: 0/1 */
221	size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
222	/* + dir: account for possible '/' */
223
224	memset(&header, 0, sizeof(header));
225	strcpy(header.name, "././@LongLink");
226	memcpy(header.mode, prefilled.mode, sizeof(prefilled));
227	PUT_OCTAL(header.size, size);
228	header.typeflag = type;
229	chksum_and_xwrite(fd, &header);
230
231	/* Write filename[/] and pad the block. */
232	/* dir=0: writes 'name<NUL>', pads */
233	/* dir=1: writes 'name', writes '/<NUL>', pads */
234	dir *= 2;
235	xwrite(fd, name, size - dir);
236	xwrite(fd, "/", dir);
237	size = (-size) & (TAR_BLOCK_SIZE-1);
238	memset(&header, 0, size);
239	xwrite(fd, &header, size);
240}
241#endif
242
243/* Write out a tar header for the specified file/directory/whatever */
244void BUG_tar_header_size(void);
245static int writeTarHeader(struct TarBallInfo *tbInfo,
246		const char *header_name, const char *fileName, struct stat *statbuf)
247{
248	struct TarHeader header;
249
250	if (sizeof(header) != 512)
251		BUG_tar_header_size();
252
253	memset(&header, 0, sizeof(struct TarHeader));
254
255	strncpy(header.name, header_name, sizeof(header.name));
256
257	/* POSIX says to mask mode with 07777. */
258	PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
259	PUT_OCTAL(header.uid, statbuf->st_uid);
260	PUT_OCTAL(header.gid, statbuf->st_gid);
261	memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
262	PUT_OCTAL(header.mtime, statbuf->st_mtime);
263
264	/* Enter the user and group names */
265	safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
266	safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
267
268	if (tbInfo->hlInfo) {
269		/* This is a hard link */
270		header.typeflag = LNKTYPE;
271		strncpy(header.linkname, tbInfo->hlInfo->name,
272				sizeof(header.linkname));
273#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
274		/* Write out long linkname if needed */
275		if (header.linkname[sizeof(header.linkname)-1])
276			writeLongname(tbInfo->tarFd, GNULONGLINK,
277					tbInfo->hlInfo->name, 0);
278#endif
279	} else if (S_ISLNK(statbuf->st_mode)) {
280		char *lpath = xmalloc_readlink_or_warn(fileName);
281		if (!lpath)
282			return FALSE;
283		header.typeflag = SYMTYPE;
284		strncpy(header.linkname, lpath, sizeof(header.linkname));
285#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
286		/* Write out long linkname if needed */
287		if (header.linkname[sizeof(header.linkname)-1])
288			writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
289#else
290		/* If it is larger than 100 bytes, bail out */
291		if (header.linkname[sizeof(header.linkname)-1]) {
292			free(lpath);
293			bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
294			return FALSE;
295		}
296#endif
297		free(lpath);
298	} else if (S_ISDIR(statbuf->st_mode)) {
299		header.typeflag = DIRTYPE;
300		/* Append '/' only if there is a space for it */
301		if (!header.name[sizeof(header.name)-1])
302			header.name[strlen(header.name)] = '/';
303	} else if (S_ISCHR(statbuf->st_mode)) {
304		header.typeflag = CHRTYPE;
305		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
306		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
307	} else if (S_ISBLK(statbuf->st_mode)) {
308		header.typeflag = BLKTYPE;
309		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
310		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
311	} else if (S_ISFIFO(statbuf->st_mode)) {
312		header.typeflag = FIFOTYPE;
313	} else if (S_ISREG(statbuf->st_mode)) {
314		if (sizeof(statbuf->st_size) > 4
315		 && statbuf->st_size > (off_t)0777777777777LL
316		) {
317			bb_error_msg_and_die("cannot store file '%s' "
318				"of size %"OFF_FMT"d, aborting",
319				fileName, statbuf->st_size);
320		}
321		header.typeflag = REGTYPE;
322		PUT_OCTAL(header.size, statbuf->st_size);
323	} else {
324		bb_error_msg("%s: unknown file type", fileName);
325		return FALSE;
326	}
327
328#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
329	/* Write out long name if needed */
330	/* (we, like GNU tar, output long linkname *before* long name) */
331	if (header.name[sizeof(header.name)-1])
332		writeLongname(tbInfo->tarFd, GNULONGNAME,
333				header_name, S_ISDIR(statbuf->st_mode));
334#endif
335
336	/* Now write the header out to disk */
337	chksum_and_xwrite(tbInfo->tarFd, &header);
338
339	/* Now do the verbose thing (or not) */
340	if (tbInfo->verboseFlag) {
341		FILE *vbFd = stdout;
342
343		if (tbInfo->tarFd == STDOUT_FILENO)	/* If the archive goes to stdout, verbose to stderr */
344			vbFd = stderr;
345		/* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
346		/* We don't have such excesses here: for us "v" == "vv" */
347		/* '/' is probably a GNUism */
348		fprintf(vbFd, "%s%s\n", header_name,
349				S_ISDIR(statbuf->st_mode) ? "/" : "");
350	}
351
352	return TRUE;
353}
354
355#if ENABLE_FEATURE_TAR_FROM
356static int exclude_file(const llist_t *excluded_files, const char *file)
357{
358	while (excluded_files) {
359		if (excluded_files->data[0] == '/') {
360			if (fnmatch(excluded_files->data, file,
361						FNM_PATHNAME | FNM_LEADING_DIR) == 0)
362				return 1;
363		} else {
364			const char *p;
365
366			for (p = file; p[0] != '\0'; p++) {
367				if ((p == file || p[-1] == '/') && p[0] != '/' &&
368					fnmatch(excluded_files->data, p,
369							FNM_PATHNAME | FNM_LEADING_DIR) == 0)
370					return 1;
371			}
372		}
373		excluded_files = excluded_files->link;
374	}
375
376	return 0;
377}
378#else
379#define exclude_file(excluded_files, file) 0
380#endif
381
382static int writeFileToTarball(const char *fileName, struct stat *statbuf,
383			void *userData, int depth ATTRIBUTE_UNUSED)
384{
385	struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
386	const char *header_name;
387	int inputFileFd = -1;
388
389	/*
390	 * Check to see if we are dealing with a hard link.
391	 * If so -
392	 * Treat the first occurance of a given dev/inode as a file while
393	 * treating any additional occurances as hard links.  This is done
394	 * by adding the file information to the HardLinkInfo linked list.
395	 */
396	tbInfo->hlInfo = NULL;
397	if (statbuf->st_nlink > 1) {
398		tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
399		if (tbInfo->hlInfo == NULL)
400			addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, fileName);
401	}
402
403	/* It is against the rules to archive a socket */
404	if (S_ISSOCK(statbuf->st_mode)) {
405		bb_error_msg("%s: socket ignored", fileName);
406		return TRUE;
407	}
408
409	/* It is a bad idea to store the archive we are in the process of creating,
410	 * so check the device and inode to be sure that this particular file isn't
411	 * the new tarball */
412	if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
413		tbInfo->statBuf.st_ino == statbuf->st_ino) {
414		bb_error_msg("%s: file is the archive; skipping", fileName);
415		return TRUE;
416	}
417
418	header_name = fileName;
419	while (header_name[0] == '/') {
420		static smallint warned;
421
422		if (!warned) {
423			bb_error_msg("removing leading '/' from member names");
424			warned = 1;
425		}
426		header_name++;
427	}
428
429#if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
430	if (strlen(fileName) >= NAME_SIZE) {
431		bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
432		return TRUE;
433	}
434#endif
435
436	if (header_name[0] == '\0')
437		return TRUE;
438
439	if (exclude_file(tbInfo->excludeList, header_name))
440		return SKIP;
441
442	/* Is this a regular file? */
443	if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
444		/* open the file we want to archive, and make sure all is well */
445		inputFileFd = open_or_warn(fileName, O_RDONLY);
446		if (inputFileFd < 0) {
447			return FALSE;
448		}
449	}
450
451	/* Add an entry to the tarball */
452	if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
453		return FALSE;
454	}
455
456	/* If it was a regular file, write out the body */
457	if (inputFileFd >= 0) {
458		size_t readSize;
459		/* Write the file to the archive. */
460		/* We record size into header first, */
461		/* and then write out file. If file shrinks in between, */
462		/* tar will be corrupted. So we don't allow for that. */
463		/* NB: GNU tar 1.16 warns and pads with zeroes */
464		/* or even seeks back and updates header */
465		bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
466		////off_t readSize;
467		////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
468		////if (readSize != statbuf->st_size && readSize >= 0) {
469		////	bb_error_msg_and_die("short read from %s, aborting", fileName);
470		////}
471
472		/* Check that file did not grow in between? */
473		/* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
474
475		close(inputFileFd);
476
477		/* Pad the file up to the tar block size */
478		/* (a few tricks here in the name of code size) */
479		readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
480		memset(block_buf, 0, readSize);
481		xwrite(tbInfo->tarFd, block_buf, readSize);
482	}
483
484	return TRUE;
485}
486
487static int writeTarFile(const int tar_fd, const int verboseFlag,
488	const unsigned long dereferenceFlag, const llist_t *include,
489	const llist_t *exclude, const int gzip)
490{
491	pid_t gzipPid = 0;
492	int errorFlag = FALSE;
493	struct TarBallInfo tbInfo;
494
495	tbInfo.hlInfoHead = NULL;
496
497	fchmod(tar_fd, 0644);
498	tbInfo.tarFd = tar_fd;
499	tbInfo.verboseFlag = verboseFlag;
500
501	/* Store the stat info for the tarball's file, so
502	 * can avoid including the tarball into itself....  */
503	if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
504		bb_perror_msg_and_die("cannot stat tar file");
505
506	if ((ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2) && gzip) {
507		int gzipDataPipe[2] = { -1, -1 };
508		int gzipStatusPipe[2] = { -1, -1 };
509		volatile int vfork_exec_errno = 0;
510		const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
511
512		xpipe(gzipDataPipe);
513		xpipe(gzipStatusPipe);
514
515		signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
516
517#if defined(__GNUC__) && __GNUC__
518		/* Avoid vfork clobbering */
519		(void) &include;
520		(void) &errorFlag;
521		(void) &zip_exec;
522#endif
523
524		gzipPid = vfork();
525
526		if (gzipPid == 0) {
527			dup2(gzipDataPipe[0], 0);
528			close(gzipDataPipe[1]);
529
530			dup2(tbInfo.tarFd, 1);
531
532			close(gzipStatusPipe[0]);
533			fcntl(gzipStatusPipe[1], F_SETFD, FD_CLOEXEC);	/* close on exec shows success */
534
535			BB_EXECLP(zip_exec, zip_exec, "-f", NULL);
536			vfork_exec_errno = errno;
537
538			close(gzipStatusPipe[1]);
539			exit(-1);
540		} else if (gzipPid > 0) {
541			close(gzipDataPipe[0]);
542			close(gzipStatusPipe[1]);
543
544			while (1) {
545				char buf;
546
547				int n = full_read(gzipStatusPipe[0], &buf, 1);
548
549				if (n == 0 && vfork_exec_errno != 0) {
550					errno = vfork_exec_errno;
551					bb_perror_msg_and_die("cannot exec %s", zip_exec);
552				} else if ((n < 0) && (errno == EAGAIN || errno == EINTR))
553					continue;	/* try it again */
554				break;
555			}
556			close(gzipStatusPipe[0]);
557
558			tbInfo.tarFd = gzipDataPipe[1];
559		} else bb_perror_msg_and_die("vfork gzip");
560	}
561
562	tbInfo.excludeList = exclude;
563
564	/* Read the directory/files and iterate over them one at a time */
565	while (include) {
566		if (!recursive_action(include->data, ACTION_RECURSE |
567				(dereferenceFlag ? ACTION_FOLLOWLINKS : 0),
568				writeFileToTarball, writeFileToTarball, &tbInfo, 0))
569		{
570			errorFlag = TRUE;
571		}
572		include = include->link;
573	}
574	/* Write two empty blocks to the end of the archive */
575	memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
576	xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
577
578	/* To be pedantically correct, we would check if the tarball
579	 * is smaller than 20 tar blocks, and pad it if it was smaller,
580	 * but that isn't necessary for GNU tar interoperability, and
581	 * so is considered a waste of space */
582
583	/* Close so the child process (if any) will exit */
584	close(tbInfo.tarFd);
585
586	/* Hang up the tools, close up shop, head home */
587	if (ENABLE_FEATURE_CLEAN_UP)
588		freeHardLinkInfo(&tbInfo.hlInfoHead);
589
590	if (errorFlag)
591		bb_error_msg("error exit delayed from previous errors");
592
593	if (gzipPid) {
594		int status;
595		if (waitpid(gzipPid, &status, 0) == -1)
596			bb_perror_msg("waitpid");
597		else if (!WIFEXITED(status) || WEXITSTATUS(status))
598			/* gzip was killed or has exited with nonzero! */
599			errorFlag = TRUE;
600	}
601	return errorFlag;
602}
603#else
604int writeTarFile(const int tar_fd, const int verboseFlag,
605	const unsigned long dereferenceFlag, const llist_t *include,
606	const llist_t *exclude, const int gzip);
607#endif /* FEATURE_TAR_CREATE */
608
609#if ENABLE_FEATURE_TAR_FROM
610static llist_t *append_file_list_to_list(llist_t *list)
611{
612	FILE *src_stream;
613	llist_t *cur = list;
614	llist_t *tmp;
615	char *line;
616	llist_t *newlist = NULL;
617
618	while (cur) {
619		src_stream = xfopen(cur->data, "r");
620		tmp = cur;
621		cur = cur->link;
622		free(tmp);
623		while ((line = xmalloc_getline(src_stream)) != NULL) {
624			/* kill trailing '/' unless the string is just "/" */
625			char *cp = last_char_is(line, '/');
626			if (cp > line)
627				*cp = '\0';
628			llist_add_to(&newlist, line);
629		}
630		fclose(src_stream);
631	}
632	return newlist;
633}
634#else
635#define append_file_list_to_list(x) 0
636#endif
637
638#if ENABLE_FEATURE_TAR_COMPRESS
639static char get_header_tar_Z(archive_handle_t *archive_handle)
640{
641	/* Can't lseek over pipes */
642	archive_handle->seek = seek_by_read;
643
644	/* do the decompression, and cleanup */
645	if (xread_char(archive_handle->src_fd) != 0x1f
646	 || xread_char(archive_handle->src_fd) != 0x9d
647	) {
648		bb_error_msg_and_die("invalid magic");
649	}
650
651	archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress, "uncompress", "uncompress", "-cf", "-", NULL);
652	archive_handle->offset = 0;
653	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
654		/* nothing */;
655
656	/* Can only do one file at a time */
657	return EXIT_FAILURE;
658}
659#else
660#define get_header_tar_Z NULL
661#endif
662
663#ifdef CHECK_FOR_CHILD_EXITCODE
664/* Looks like it isn't needed - tar detects malformed (truncated)
665 * archive if e.g. bunzip2 fails */
666static int child_error;
667
668static void handle_SIGCHLD(int status)
669{
670	/* Actually, 'status' is a signo. We reuse it for other needs */
671
672	/* Wait for any child without blocking */
673	if (waitpid(-1, &status, WNOHANG) < 0)
674		/* wait failed?! I'm confused... */
675		return;
676
677	if (WIFEXITED(status) && WEXITSTATUS(status)==0)
678		/* child exited with 0 */
679		return;
680	/* Cannot happen?
681	if (!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
682	child_error = 1;
683}
684#endif
685
686enum {
687	OPTBIT_KEEP_OLD = 7,
688	USE_FEATURE_TAR_CREATE(  OPTBIT_CREATE      ,)
689	USE_FEATURE_TAR_CREATE(  OPTBIT_DEREFERENCE ,)
690	USE_FEATURE_TAR_BZIP2(   OPTBIT_BZIP2       ,)
691	USE_FEATURE_TAR_LZMA(    OPTBIT_LZMA        ,)
692	USE_FEATURE_TAR_FROM(    OPTBIT_INCLUDE_FROM,)
693	USE_FEATURE_TAR_FROM(    OPTBIT_EXCLUDE_FROM,)
694	USE_FEATURE_TAR_GZIP(    OPTBIT_GZIP        ,)
695	USE_FEATURE_TAR_COMPRESS(OPTBIT_COMPRESS    ,)
696	OPTBIT_NOPRESERVE_OWN,
697	OPTBIT_NOPRESERVE_PERM,
698	OPT_TEST         = 1 << 0, // t
699	OPT_EXTRACT      = 1 << 1, // x
700	OPT_BASEDIR      = 1 << 2, // C
701	OPT_TARNAME      = 1 << 3, // f
702	OPT_2STDOUT      = 1 << 4, // O
703	OPT_P            = 1 << 5, // p
704	OPT_VERBOSE      = 1 << 6, // v
705	OPT_KEEP_OLD     = 1 << 7, // k
706	OPT_CREATE       = USE_FEATURE_TAR_CREATE(  (1<<OPTBIT_CREATE      )) + 0, // c
707	OPT_DEREFERENCE  = USE_FEATURE_TAR_CREATE(  (1<<OPTBIT_DEREFERENCE )) + 0, // h
708	OPT_BZIP2        = USE_FEATURE_TAR_BZIP2(   (1<<OPTBIT_BZIP2       )) + 0, // j
709	OPT_LZMA         = USE_FEATURE_TAR_LZMA(    (1<<OPTBIT_LZMA        )) + 0, // a
710	OPT_INCLUDE_FROM = USE_FEATURE_TAR_FROM(    (1<<OPTBIT_INCLUDE_FROM)) + 0, // T
711	OPT_EXCLUDE_FROM = USE_FEATURE_TAR_FROM(    (1<<OPTBIT_EXCLUDE_FROM)) + 0, // X
712	OPT_GZIP         = USE_FEATURE_TAR_GZIP(    (1<<OPTBIT_GZIP        )) + 0, // z
713	OPT_COMPRESS     = USE_FEATURE_TAR_COMPRESS((1<<OPTBIT_COMPRESS    )) + 0, // Z
714	OPT_NOPRESERVE_OWN  = 1 << OPTBIT_NOPRESERVE_OWN , // no-same-owner
715	OPT_NOPRESERVE_PERM = 1 << OPTBIT_NOPRESERVE_PERM, // no-same-permissions
716};
717#if ENABLE_FEATURE_TAR_LONG_OPTIONS
718static const char tar_longopts[] ALIGN1 =
719	"list\0"                No_argument       "t"
720	"extract\0"             No_argument       "x"
721	"directory\0"           Required_argument "C"
722	"file\0"                Required_argument "f"
723	"to-stdout\0"           No_argument       "O"
724	"same-permissions\0"    No_argument       "p"
725	"verbose\0"             No_argument       "v"
726	"keep-old\0"            No_argument       "k"
727# if ENABLE_FEATURE_TAR_CREATE
728	"create\0"              No_argument       "c"
729	"dereference\0"         No_argument       "h"
730# endif
731# if ENABLE_FEATURE_TAR_BZIP2
732	"bzip2\0"               No_argument       "j"
733# endif
734# if ENABLE_FEATURE_TAR_LZMA
735	"lzma\0"                No_argument       "a"
736# endif
737# if ENABLE_FEATURE_TAR_FROM
738	"files-from\0"          Required_argument "T"
739	"exclude-from\0"        Required_argument "X"
740# endif
741# if ENABLE_FEATURE_TAR_GZIP
742	"gzip\0"                No_argument       "z"
743# endif
744# if ENABLE_FEATURE_TAR_COMPRESS
745	"compress\0"            No_argument       "Z"
746# endif
747	"no-same-owner\0"       No_argument       "\xfd"
748	"no-same-permissions\0" No_argument       "\xfe"
749	/* --exclude takes next bit position in option mask, */
750	/* therefore we have to either put it _after_ --no-same-perm */
751	/* or add OPT[BIT]_EXCLUDE before OPT[BIT]_NOPRESERVE_OWN */
752# if ENABLE_FEATURE_TAR_FROM
753	"exclude\0"             Required_argument "\xff"
754# endif
755	;
756#endif
757
758int tar_main(int argc, char **argv);
759int tar_main(int argc, char **argv)
760{
761	char (*get_header_ptr)(archive_handle_t *) = get_header_tar;
762	archive_handle_t *tar_handle;
763	char *base_dir = NULL;
764	const char *tar_filename = "-";
765	unsigned opt;
766	int verboseFlag = 0;
767#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
768	llist_t *excludes = NULL;
769#endif
770
771	/* Initialise default values */
772	tar_handle = init_handle();
773	tar_handle->flags = ARCHIVE_CREATE_LEADING_DIRS
774	                  | ARCHIVE_PRESERVE_DATE
775	                  | ARCHIVE_EXTRACT_UNCONDITIONAL;
776
777	/* Prepend '-' to the first argument if required */
778	opt_complementary = "--:" // first arg is options
779		"tt:vv:" // count -t,-v
780		"?:" // bail out with usage instead of error return
781		"X::T::" // cumulative lists
782#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
783		"\xff::" // cumulative lists for --exclude
784#endif
785		USE_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
786		USE_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
787		SKIP_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
788#if ENABLE_FEATURE_TAR_LONG_OPTIONS
789	applet_long_options = tar_longopts;
790#endif
791	opt = getopt32(argv,
792		"txC:f:Opvk"
793		USE_FEATURE_TAR_CREATE(  "ch"  )
794		USE_FEATURE_TAR_BZIP2(   "j"   )
795		USE_FEATURE_TAR_LZMA(    "a"   )
796		USE_FEATURE_TAR_FROM(    "T:X:")
797		USE_FEATURE_TAR_GZIP(    "z"   )
798		USE_FEATURE_TAR_COMPRESS("Z"   )
799		, &base_dir // -C dir
800		, &tar_filename // -f filename
801		USE_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
802		USE_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
803#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
804		, &excludes // --exclude
805#endif
806		, &verboseFlag // combined count for -t and -v
807		, &verboseFlag // combined count for -t and -v
808		);
809
810	if (verboseFlag) tar_handle->action_header = header_verbose_list;
811	if (verboseFlag == 1) tar_handle->action_header = header_list;
812
813	if (opt & OPT_EXTRACT)
814		tar_handle->action_data = data_extract_all;
815
816	if (opt & OPT_2STDOUT)
817		tar_handle->action_data = data_extract_to_stdout;
818
819	if (opt & OPT_KEEP_OLD)
820		tar_handle->flags &= ~ARCHIVE_EXTRACT_UNCONDITIONAL;
821
822	if (opt & OPT_NOPRESERVE_OWN)
823		tar_handle->flags |= ARCHIVE_NOPRESERVE_OWN;
824
825	if (opt & OPT_NOPRESERVE_PERM)
826		tar_handle->flags |= ARCHIVE_NOPRESERVE_PERM;
827
828	if (opt & OPT_GZIP)
829		get_header_ptr = get_header_tar_gz;
830
831	if (opt & OPT_BZIP2)
832		get_header_ptr = get_header_tar_bz2;
833
834	if (opt & OPT_LZMA)
835		get_header_ptr = get_header_tar_lzma;
836
837	if (opt & OPT_COMPRESS)
838		get_header_ptr = get_header_tar_Z;
839
840#if ENABLE_FEATURE_TAR_FROM
841	tar_handle->reject = append_file_list_to_list(tar_handle->reject);
842#if ENABLE_FEATURE_TAR_LONG_OPTIONS
843	/* Append excludes to reject */
844	while (excludes) {
845		llist_t *next = excludes->link;
846		excludes->link = tar_handle->reject;
847		tar_handle->reject = excludes;
848		excludes = next;
849	}
850#endif
851	tar_handle->accept = append_file_list_to_list(tar_handle->accept);
852#endif
853
854	/* Check if we are reading from stdin */
855	if (argv[optind] && *argv[optind] == '-') {
856		/* Default is to read from stdin, so just skip to next arg */
857		optind++;
858	}
859
860	/* Setup an array of filenames to work with */
861	/* TODO: This is the same as in ar, separate function ? */
862	while (optind < argc) {
863		/* kill trailing '/' unless the string is just "/" */
864		char *cp = last_char_is(argv[optind], '/');
865		if (cp > argv[optind])
866			*cp = '\0';
867		llist_add_to_end(&tar_handle->accept, argv[optind]);
868		optind++;
869	}
870
871	if (tar_handle->accept || tar_handle->reject)
872		tar_handle->filter = filter_accept_reject_list;
873
874	/* Open the tar file */
875	{
876		FILE *tar_stream;
877		int flags;
878
879		if (opt & OPT_CREATE) {
880			/* Make sure there is at least one file to tar up.  */
881			if (tar_handle->accept == NULL)
882				bb_error_msg_and_die("empty archive");
883
884			tar_stream = stdout;
885			/* Mimicking GNU tar 1.15.1: */
886			flags = O_WRONLY|O_CREAT|O_TRUNC;
887		/* was doing unlink; open(O_WRONLY|O_CREAT|O_EXCL); why? */
888		} else {
889			tar_stream = stdin;
890			flags = O_RDONLY;
891		}
892
893		if (LONE_DASH(tar_filename)) {
894			tar_handle->src_fd = fileno(tar_stream);
895			tar_handle->seek = seek_by_read;
896		} else {
897			tar_handle->src_fd = xopen(tar_filename, flags);
898		}
899	}
900
901	if (base_dir)
902		xchdir(base_dir);
903
904#ifdef CHECK_FOR_CHILD_EXITCODE
905	/* We need to know whether child (gzip/bzip/etc) exits abnormally */
906	signal(SIGCHLD, handle_SIGCHLD);
907#endif
908
909	/* create an archive */
910	if (opt & OPT_CREATE) {
911		int zipMode = 0;
912		if (ENABLE_FEATURE_TAR_GZIP && get_header_ptr == get_header_tar_gz)
913			zipMode = 1;
914		if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
915			zipMode = 2;
916		/* NB: writeTarFile() closes tar_handle->src_fd */
917		return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
918				tar_handle->accept,
919				tar_handle->reject, zipMode);
920	}
921
922	while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
923		/* nothing */;
924
925	/* Check that every file that should have been extracted was */
926	while (tar_handle->accept) {
927		if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
928		 && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
929		) {
930			bb_error_msg_and_die("%s: not found in archive",
931				tar_handle->accept->data);
932		}
933		tar_handle->accept = tar_handle->accept->link;
934	}
935	if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
936		close(tar_handle->src_fd);
937
938	return EXIT_SUCCESS;
939}
940