1 /* vi: set sw=4 ts=4: */
4 * Mini tar implementation for busybox Note, that as of BusyBox 0.43 tar has
5 * been completely rewritten from the ground up. It still has remnents of the
6 * old code lying about, but it pretty different (i.e. cleaner, less global
9 * Copyright (C) 1999 by Lineo, inc.
10 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
12 * Based in part in the tar implementation in sash
13 * Copyright (c) 1999 by David I. Bell
14 * Permission is granted to use, distribute, or modify this source,
15 * provided that this copyright notice remains intact.
16 * Permission to distribute sash derived code under the GPL has been granted.
18 * Based in part on the tar implementation in busybox-0.28
19 * Copyright (C) 1995 Bruce Perens
20 * This is free software under the GNU General Public License.
22 * This program is free software; you can redistribute it and/or modify
23 * it under the terms of the GNU General Public License as published by
24 * the Free Software Foundation; either version 2 of the License, or
25 * (at your option) any later version.
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
30 * General Public License for more details.
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
40 #define BB_DECLARE_EXTERN
41 #define bb_need_io_error
50 #include <sys/types.h>
51 #include <sys/sysmacros.h>
52 #include <sys/param.h> /* for PATH_MAX */
55 #ifdef BB_FEATURE_TAR_CREATE
57 static const char tar_usage[] =
58 "tar -[cxtvOf] [tarFileName] [FILE] ...\n\n"
59 "Create, extract, or list files from a tar file.\n\n"
62 "\tc=create, x=extract, t=list contents, v=verbose,\n"
63 "\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
67 static const char tar_usage[] =
68 "tar -[xtvOf] [tarFileName] [FILE] ...\n\n"
69 "Extract, or list files stored in a tar file. This\n"
70 "version of tar does not support creation of tar files.\n\n"
73 "\tx=extract, t=list contents, v=verbose,\n"
74 "\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
79 /* Tar file constants */
81 #define MAJOR(dev) (((dev)>>8)&0xff)
82 #define MINOR(dev) ((dev)&0xff)
86 /* POSIX tar Header Block, from POSIX 1003.1-1990 */
90 char name[100]; /* 0 */
91 char mode[8]; /* 100 */
92 char uid[8]; /* 108 */
93 char gid[8]; /* 116 */
94 char size[12]; /* 124 */
95 char mtime[12]; /* 136 */
96 char chksum[8]; /* 148 */
97 char typeflag; /* 156 */
98 char linkname[100]; /* 157 */
99 char magic[6]; /* 257 */
100 char version[2]; /* 263 */
101 char uname[32]; /* 265 */
102 char gname[32]; /* 297 */
103 char devmajor[8]; /* 329 */
104 char devminor[8]; /* 337 */
105 char prefix[155]; /* 345 */
108 typedef struct TarHeader TarHeader;
111 /* A few useful constants */
112 #define TAR_MAGIC "ustar" /* ustar and a null */
113 #define TAR_VERSION "00" /* 00 and no null */
114 #define TAR_MAGIC_LEN 6
115 #define TAR_VERSION_LEN 2
116 #define TAR_NAME_LEN 100
117 #define TAR_BLOCK_SIZE 512
119 /* A nice enum with all the possible tar file content types */
122 REGTYPE = '0', /* regular file */
123 REGTYPE0 = '\0', /* regular file (ancient bug compat)*/
124 LNKTYPE = '1', /* hard link */
125 SYMTYPE = '2', /* symbolic link */
126 CHRTYPE = '3', /* character special */
127 BLKTYPE = '4', /* block special */
128 DIRTYPE = '5', /* directory */
129 FIFOTYPE = '6', /* FIFO special */
130 CONTTYPE = '7', /* reserved */
132 typedef enum TarFileType TarFileType;
134 /* This struct ignores magic, non-numeric user name,
135 * non-numeric group name, and the checksum, since
136 * these are all ignored by BusyBox tar. */
139 int tarFd; /* An open file descriptor for reading from the tarball */
140 char * name; /* File name */
141 mode_t mode; /* Unix mode, including device bits. */
142 uid_t uid; /* Numeric UID */
143 gid_t gid; /* Numeric GID */
144 size_t size; /* Size of file */
145 time_t mtime; /* Last-modified time */
146 enum TarFileType type; /* Regular, directory, link, etc */
147 char * linkname; /* Name for symbolic and hard links */
148 long devmajor; /* Major number for special device */
149 long devminor; /* Minor number for special device */
151 typedef struct TarInfo TarInfo;
154 static const unsigned long TarChecksumOffset = (const unsigned long)&(((TarHeader *)0)->chksum);
157 /* Local procedures to restore files from a tar file. */
158 static int readTarFile(const char* tarName, int extractFlag, int listFlag,
159 int tostdoutFlag, int verboseFlag);
163 #ifdef BB_FEATURE_TAR_CREATE
164 /* Local procedures to save files into a tar file. */
165 static int writeTarFile(const char* tarName, int extractFlag, int listFlag,
166 int tostdoutFlag, int verboseFlag, int argc, char **argv);
167 static int putOctal(char *cp, int len, long value);
172 extern int tar_main(int argc, char **argv)
174 const char *tarName=NULL;
176 int listFlag = FALSE;
177 int extractFlag = FALSE;
178 int createFlag = FALSE;
179 int verboseFlag = FALSE;
180 int tostdoutFlag = FALSE;
190 options = (*argv++) + 1;
195 for (; *options; options++) {
199 fatalError( "Only one 'f' option allowed\n");
203 fatalError( "Option requires an argument: No file specified\n");
209 if (extractFlag == TRUE || createFlag == TRUE)
215 if (listFlag == TRUE || createFlag == TRUE)
220 if (extractFlag == TRUE || listFlag == TRUE)
239 fatalError( "Unknown tar flag '%c'\n"
240 "Try `tar --help' for more information\n", *options);
245 * Do the correct type of action supplying the rest of the
246 * command line arguments as the list of files to process.
248 if (createFlag == TRUE) {
249 #ifndef BB_FEATURE_TAR_CREATE
250 fatalError( "This version of tar was not compiled with tar creation support.\n");
252 exit(writeTarFile(tarName, extractFlag, listFlag, tostdoutFlag, verboseFlag, argc, argv));
255 exit(readTarFile(tarName, extractFlag, listFlag, tostdoutFlag, verboseFlag));
259 fatalError( "Exactly one of 'c', 'x' or 't' must be specified\n");
263 tarExtractRegularFile(TarInfo *header, int extractFlag, int tostdoutFlag)
267 size_t actualWriteSz;
269 size_t size = header->size;
270 int outFd=fileno(stdout);
272 /* Open the file to be written, if a file is supposed to be written */
273 if (extractFlag==TRUE && tostdoutFlag==FALSE) {
274 if ((outFd=open(header->name, O_CREAT|O_TRUNC|O_WRONLY, header->mode & ~S_IFMT)) < 0)
275 errorMsg(io_error, header->name, strerror(errno));
276 /* Create the path to the file, just in case it isn't there...
277 * This should not screw up path permissions or anything. */
278 createPath(header->name, 0777);
281 /* Write out the file, if we are supposed to be doing that */
284 if ( size > sizeof(buffer) )
285 writeSize = readSize = sizeof(buffer);
287 int mod = size % 512;
289 readSize = size + (512 - mod);
294 if ( (readSize = fullRead(header->tarFd, buffer, readSize)) <= 0 ) {
295 /* Tarball seems to have a problem */
296 errorMsg("tar: Unexpected EOF in archive\n");
299 if ( readSize < writeSize )
300 writeSize = readSize;
302 /* Write out the file, if we are supposed to be doing that */
303 if (extractFlag==TRUE) {
305 if ((actualWriteSz=fullWrite(outFd, buffer, writeSize)) != writeSize ) {
306 /* Output file seems to have a problem */
307 errorMsg(io_error, header->name, strerror(errno));
312 size -= actualWriteSz;
315 /* Now we are done writing the file out, so try
316 * and fix up the permissions and whatnot */
317 if (extractFlag==TRUE && tostdoutFlag==FALSE) {
319 /* Now set permissions etc for the new file */
320 fchown(outFd, header->uid, header->gid);
321 fchmod(outFd, header->mode & ~S_IFMT);
323 /* File must be closed before trying to change the date */
325 t.modtime = header->mtime;
326 utime(header->name, &t);
331 fixUpPermissions(TarInfo *header)
334 /* Now set permissions etc for the new file */
335 chown(header->name, header->uid, header->gid);
336 chmod(header->name, header->mode);
339 t.modtime = header->mtime;
340 utime(header->name, &t);
344 tarExtractDirectory(TarInfo *header, int extractFlag, int tostdoutFlag)
347 if (extractFlag==FALSE || tostdoutFlag==TRUE)
350 if (createPath(header->name, header->mode) != TRUE) {
351 errorMsg("Error creating directory '%s': %s", header->name, strerror(errno));
354 /* make the final component, just in case it was
355 * omitted by createPath() (which will skip the
356 * directory if it doesn't have a terminating '/') */
357 if (mkdir(header->name, header->mode) == 0) {
358 fixUpPermissions(header);
363 tarExtractHardLink(TarInfo *header, int extractFlag, int tostdoutFlag)
365 if (extractFlag==FALSE || tostdoutFlag==TRUE)
368 if (link(header->linkname, header->name) < 0) {
369 errorMsg("Error creating hard link '%s': %s\n", header->linkname, strerror(errno));
373 /* Now set permissions etc for the new directory */
374 fixUpPermissions(header);
378 tarExtractSymLink(TarInfo *header, int extractFlag, int tostdoutFlag)
380 if (extractFlag==FALSE || tostdoutFlag==TRUE)
384 if (symlink(header->linkname, header->name) < 0) {
385 errorMsg("Error creating symlink '%s': %s\n", header->linkname, strerror(errno));
388 /* Try to change ownership of the symlink.
389 * If libs doesn't support that, don't bother.
390 * Changing the pointed-to-file is the Wrong Thing(tm).
392 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
393 lchown(header->name, header->uid, header->gid);
396 /* Do not change permissions or date on symlink,
397 * since it changes the pointed to file instead. duh. */
399 fprintf(stderr, "Cannot create symbolic links\n");
404 tarExtractSpecial(TarInfo *header, int extractFlag, int tostdoutFlag)
406 if (extractFlag==FALSE || tostdoutFlag==TRUE)
409 if (S_ISCHR(header->mode) || S_ISBLK(header->mode) || S_ISSOCK(header->mode)) {
410 mknod(header->name, header->mode, makedev(header->devmajor, header->devminor));
411 } else if (S_ISFIFO(header->mode)) {
412 mkfifo(header->name, header->mode);
414 open(header->name, O_WRONLY | O_CREAT | O_TRUNC, header->mode);
417 /* Now set permissions etc for the new directory */
418 fixUpPermissions(header);
421 /* Read an octal value in a field of the specified width, with optional
422 * spaces on both sides of the number and with an optional null character
423 * at the end. Returns -1 on an illegal format. */
424 static long getOctal(const char *cp, int size)
428 for(;(size > 0) && (*cp == ' '); cp++, size--);
429 if ((size == 0) || !isOctal(*cp))
431 for(; (size > 0) && isOctal(*cp); size--) {
432 val = val * 8 + *cp++ - '0';
434 for (;(size > 0) && (*cp == ' '); cp++, size--);
435 if ((size > 0) && *cp)
441 /* Parse the tar header and fill in the nice struct with the details */
443 readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
447 unsigned char *s = (unsigned char *)rawHeader;
449 header->name = rawHeader->name;
450 header->mode = getOctal(rawHeader->mode, sizeof(rawHeader->mode));
451 header->uid = getOctal(rawHeader->uid, sizeof(rawHeader->uid));
452 header->gid = getOctal(rawHeader->gid, sizeof(rawHeader->gid));
453 header->size = getOctal(rawHeader->size, sizeof(rawHeader->size));
454 header->mtime = getOctal(rawHeader->mtime, sizeof(rawHeader->mtime));
455 chksum = getOctal(rawHeader->chksum, sizeof(rawHeader->chksum));
456 header->type = rawHeader->typeflag;
457 header->linkname = rawHeader->linkname;
458 header->devmajor = getOctal(rawHeader->devmajor, sizeof(rawHeader->devmajor));
459 header->devminor = getOctal(rawHeader->devminor, sizeof(rawHeader->devminor));
461 /* Check the checksum */
462 sum = ' ' * sizeof(rawHeader->chksum);
463 for ( i = TarChecksumOffset; i > 0; i-- )
465 s += sizeof(rawHeader->chksum);
466 for ( i = (512 - TarChecksumOffset - sizeof(rawHeader->chksum)); i > 0; i-- )
475 * Read a tar file and extract or list the specified files within it.
476 * If the list is empty than all files are extracted or listed.
478 static int readTarFile(const char* tarName, int extractFlag, int listFlag,
479 int tostdoutFlag, int verboseFlag)
485 int alreadyWarned=FALSE;
486 //int skipFileFlag=FALSE;
488 /* Open the tar file for reading. */
489 if (!strcmp(tarName, "-"))
490 tarFd = fileno(stdin);
492 tarFd = open(tarName, O_RDONLY);
494 errorMsg( "Error opening '%s': %s\n", tarName, strerror(errno));
498 /* Set the umask for this process so it doesn't
499 * screw up permission setting for us later. */
502 /* Read the tar file, and iterate over it one file at a time */
503 while ( (status = fullRead(tarFd, (char*)&rawHeader, TAR_BLOCK_SIZE)) == TAR_BLOCK_SIZE ) {
505 /* First, try to read the header */
506 if ( readTarHeader(&rawHeader, &header) == FALSE ) {
508 if ( *(header.name) == '\0' ) {
512 errorMsg("Bad tar header, skipping\n");
516 if ( *(header.name) == '\0' )
519 /* Check for and relativify any absolute paths */
520 if ( *(header.name) == '/' ) {
522 while (*(header.name) == '/')
525 if (alreadyWarned == FALSE) {
526 errorMsg("Absolute path detected, removing leading slashes\n");
527 alreadyWarned = TRUE;
531 /* Special treatment if the list (-t) flag is on */
532 if (verboseFlag == TRUE && extractFlag == FALSE) {
535 struct tm *tm = localtime (&(header.mtime));
537 len=printf("%s %d/%-d ", modeString(header.mode), header.uid, header.gid);
538 if (header.type==CHRTYPE || header.type==BLKTYPE) {
539 len1=snprintf(buf, sizeof(buf), "%ld,%-ld ",
540 header.devmajor, header.devminor);
542 len1=snprintf(buf, sizeof(buf), "%d ", header.size);
544 /* Jump through some hoops to make the columns match up */
545 for(;(len+len1)<31;len++)
549 /* Use ISO 8610 time format */
551 printf ("%04d-%02d-%02d %02d:%02d:%02d ",
552 tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
553 tm->tm_hour, tm->tm_min, tm->tm_sec);
556 /* List contents if we are supposed to do that */
557 if (verboseFlag == TRUE || listFlag == TRUE) {
558 /* Now the normal listing */
559 printf("%s", header.name);
560 /* If this is a link, say so */
561 if (header.type==LNKTYPE)
562 printf(" link to %s", header.linkname);
563 else if (header.type==SYMTYPE)
564 printf(" -> %s", header.linkname);
569 /* See if we want to restore this file or not */
571 if (wantFileName(outName) == FALSE) {
576 /* If we got here, we can be certain we have a legitimate
577 * header to work with. So work with it. */
578 switch ( header.type ) {
581 /* If the name ends in a '/' then assume it is
582 * supposed to be a directory, and fall through */
583 if (header.name[strlen(header.name)-1] != '/') {
584 tarExtractRegularFile(&header, extractFlag, tostdoutFlag);
588 tarExtractDirectory( &header, extractFlag, tostdoutFlag);
591 tarExtractHardLink( &header, extractFlag, tostdoutFlag);
594 tarExtractSymLink( &header, extractFlag, tostdoutFlag);
599 tarExtractSpecial( &header, extractFlag, tostdoutFlag);
608 /* Bummer - we read a partial header */
609 errorMsg( "Error reading '%s': %s\n", tarName, strerror(errno));
615 /* Stuff to do when we are done */
618 if ( *(header.name) == '\0' ) {
619 if (errorFlag==FALSE)
626 #ifdef BB_FEATURE_TAR_CREATE
628 /* Put an octal string into the specified buffer.
629 * The number is zero and space padded and possibly null padded.
630 * Returns TRUE if successful. */
631 static int putOctal (char *cp, int len, long value)
637 /* Create a string of the specified length with an initial space,
638 * leading zeroes and the octal number, and a trailing null. */
639 tempString = tempBuffer;
641 sprintf (tempString, " %0*lo", len - 2, value);
643 tempLength = strlen (tempString) + 1;
645 /* If the string is too large, suppress the leading space. */
646 if (tempLength > len) {
651 /* If the string is still too large, suppress the trailing null. */
652 if (tempLength > len)
655 /* If the string is still too large, fail. */
656 if (tempLength > len)
659 /* Copy the string to the field. */
660 memcpy (cp, tempString, len);
665 /* Write out a tar header for the specified file */
667 writeTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
671 unsigned char *s = (unsigned char *)rawHeader;
673 struct TarHeader header;
675 strcpy(header.name, fileName);
676 putOctal(header.mode, sizeof(header.mode), statbuf->st_mode & 0777);
677 putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
678 putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
679 putOctal(header.size, sizeof(header.size), statbuf->st_size);
680 putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
682 if (S_ISLNK(statbuf.st_mode)) {
683 header.type = LNKTYPE;
685 } else if (S_ISDIR(statbuf.st_mode)) {
686 header.type = DIRTYPE;
687 } else if (S_ISCHR(statbuf.st_mode)) {
688 header.type = CHRTYPE;
689 } else if (S_ISBLK(statbuf.st_mode)) {
690 header.type = BLKTYPE;
691 } else if (S_ISFIFO(statbuf.st_mode)) {
692 header.type = FIFOTYPE;
693 } else if (S_ISSOCK(statbuf.st_mode)) {
694 header.type = S_ISSOCK;
695 } else if (S_ISLNK(statbuf.st_mode)) {
696 header.type = LNKTYPE;
697 } else if (S_ISLNK(statbuf.st_mode)) {
698 header.type = REGTYPE;
701 header->linkname = rawHeader->linkname;
702 header->devmajor = getOctal(rawHeader->devmajor, sizeof(rawHeader->devmajor));
703 header->devminor = getOctal(rawHeader->devminor, sizeof(rawHeader->devminor));
705 /* Write out the checksum */
706 chksum = getOctal(rawHeader->chksum, sizeof(rawHeader->chksum));
713 static int fileAction(const char *fileName, struct stat *statbuf, void* userData)
715 int *tarFd=(int*)userData;
716 dprintf(*tarFd, "%s\n", fileName);
720 static int writeTarFile(const char* tarName, int extractFlag, int listFlag,
721 int tostdoutFlag, int verboseFlag, int argc, char **argv)
724 //int errorFlag=FALSE;
725 //TarHeader rawHeader;
727 //int alreadyWarned=FALSE;
728 //int skipFileFlag=FALSE;
729 struct stat tarballStat;
733 /* Make sure there is at least one file to tar up. */
735 fatalError("tar: Cowardly refusing to create an empty archive\n");
737 /* Open the tar file for writing. */
738 if (tostdoutFlag == TRUE)
739 tarFd = fileno(stdout);
741 tarFd = open (tarName, O_WRONLY | O_CREAT | O_TRUNC, 0644);
743 errorMsg( "Error opening '%s': %s\n", tarName, strerror(errno));
746 /* Store the device and inode of the tarball, so we can be sure
747 * not to try and include it into itself.... */
748 if (fstat(tarFd, &tarballStat) < 0)
749 fatalError(io_error, tarName, strerror(errno));
750 tarDev = tarballStat.st_dev;
751 tarInode = tarballStat.st_ino;
753 /* Set the umask for this process so it doesn't
754 * screw up permission setting for us later. */
757 /* Read the directory/files and iterate over them one at a time */
759 if (recursiveAction(*argv++, TRUE, FALSE, FALSE,
760 fileAction, fileAction, (void*) &tarFd) == FALSE) {