1 /* vi: set sw=4 ts=4: */
3 * Mini tar implementation for busybox based on code taken from sash.
5 * Copyright (c) 1999 by David I. Bell
6 * Permission is granted to use, distribute, or modify this source,
7 * provided that this copyright notice remains intact.
9 * Permission to distribute this code under the GPL has been granted.
11 * Modified for busybox by Erik Andersen <andersee@debian.org>
12 * Adjusted to grok stdin/stdout options.
14 * Modified to handle device special files by Matt Porter
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 * General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
42 #include <sys/types.h>
43 #include <sys/sysmacros.h>
44 #include <sys/param.h> /* for PATH_MAX */
47 #ifdef BB_FEATURE_TAR_CREATE
49 static const char tar_usage[] =
50 "tar -[cxtvOf] [tarFileName] [FILE] ...\n\n"
51 "Create, extract, or list files from a tar file.\n\n"
54 "\tc=create, x=extract, t=list contents, v=verbose,\n"
55 "\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
59 static const char tar_usage[] =
60 "tar -[xtvOf] [tarFileName] [FILE] ...\n\n"
61 "Extract, or list files stored in a tar file. This\n"
62 "version of tar does not support creation of tar files.\n\n"
65 "\tx=extract, t=list contents, v=verbose,\n"
66 "\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
74 #define TAR_BLOCK_SIZE 512
75 #define TAR_NAME_SIZE 100
79 * The POSIX (and basic GNU) tar header format.
80 * This structure is always embedded in a TAR_BLOCK_SIZE sized block
81 * with zero padding. We only process this information minimally.
84 char name[TAR_NAME_SIZE];
92 char linkName[TAR_NAME_SIZE];
102 #define TAR_MAGIC "ustar"
103 #define TAR_VERSION "00"
105 #define TAR_TYPE_REGULAR '0'
106 #define TAR_TYPE_HARD_LINK '1'
107 #define TAR_TYPE_SOFT_LINK '2'
114 static int extractFlag;
115 static int createFlag;
116 static int verboseFlag;
117 static int tostdoutFlag;
119 static int inHeader; // <- check me
120 static int badHeader;
121 static int errorFlag;
122 static int skipFileFlag;
123 static int warnedRoot;
127 static const char *outName;
135 * Static data associated with the tar file.
137 static const char *tarName;
140 static ino_t tarInode;
144 * Local procedures to restore files from a tar file.
146 static void readTarFile(int fileCount, char **fileTable);
147 static void readData(const char *cp, int count);
148 static long getOctal(const char *cp, int len);
150 static void readHeader(const TarHeader * hp,
152 int fileCount, char **fileTable);
154 static int wantFileName(const char *fileName,
156 int fileCount, char **fileTable);
158 #ifdef BB_FEATURE_TAR_CREATE
160 * Local procedures to save files into a tar file.
162 static void saveFile(const char *fileName, int seeLinks);
164 static void saveRegularFile(const char *fileName,
166 const struct stat *statbuf);
168 static void saveDirectory(const char *fileName,
170 const struct stat *statbuf);
172 static void writeHeader(const char *fileName, const struct stat *statbuf);
174 static void writeTarFile(int fileCount, char **fileTable);
175 static void writeTarBlock(const char *buf, int len);
176 static int putOctal(char *cp, int len, long value);
181 extern int tar_main(int argc, char **argv)
197 tostdoutFlag = FALSE;
207 options = (*argv++) + 1;
212 for (; *options; options++) {
215 if (tarName != NULL) {
216 fprintf(stderr, "Only one 'f' option allowed\n");
227 if (extractFlag == TRUE || createFlag == TRUE)
233 if (listFlag == TRUE || createFlag == TRUE)
238 if (extractFlag == TRUE || listFlag == TRUE)
256 fprintf(stderr, "Unknown tar flag '%c'\n"
257 "Try `tar --help' for more information\n", *options);
263 * Do the correct type of action supplying the rest of the
264 * command line arguments as the list of files to process.
266 if (createFlag == TRUE) {
267 #ifndef BB_FEATURE_TAR_CREATE
269 "This version of tar was not compiled with tar creation support.\n");
272 writeTarFile(argc, argv);
275 readTarFile(argc, argv);
277 if (errorFlag == TRUE) {
278 fprintf(stderr, "\n");
283 fprintf(stderr, "Exactly one of 'c', 'x' or 't' must be specified\n");
289 * Read a tar file and extract or list the specified files within it.
290 * If the list is empty than all files are extracted or listed.
292 static void readTarFile(int fileCount, char **fileTable)
300 skipFileFlag = FALSE;
308 blockSize = sizeof(buf);
312 * Open the tar file for reading.
314 if ((tarName == NULL) || !strcmp(tarName, "-")) {
315 tarFd = fileno(stdin);
317 tarFd = open(tarName, O_RDONLY);
326 * Read blocks from the file until an end of file header block
327 * has been seen. (A real end of file from a read is an error.)
329 while (eofFlag == FALSE) {
331 * Read the next block of data if necessary.
332 * This will be a large block if possible, which we will
333 * then process in the small tar blocks.
337 inCc = fullRead(tarFd, buf, blockSize);
347 "Unexpected end of file from \"%s\"", tarName);
354 * If we are expecting a header block then examine it.
356 if (inHeader == TRUE) {
357 readHeader((const TarHeader *) cp, fileCount, fileTable);
359 cp += TAR_BLOCK_SIZE;
360 inCc -= TAR_BLOCK_SIZE;
366 * We are currently handling the data for a file.
367 * Process the minimum of the amount of data we have available
368 * and the amount left to be processed for the file.
378 * If the amount left isn't an exact multiple of the tar block
379 * size then round it up to the next block boundary since there
380 * is padding at the end of the file.
382 if (cc % TAR_BLOCK_SIZE)
383 cc += TAR_BLOCK_SIZE - (cc % TAR_BLOCK_SIZE);
391 * Close the tar file if needed.
393 if ((tarFd >= 0) && (close(tarFd) < 0))
397 * Close the output file if needed.
398 * This is only done here on a previous error and so no
399 * message is required on errors.
401 if (tostdoutFlag == FALSE) {
410 * Examine the header block that was just read.
411 * This can specify the information for another file, or it can mark
412 * the end of the tar file.
415 readHeader(const TarHeader * hp, int fileCount, char **fileTable)
428 * If the block is completely empty, then this is the end of the
429 * archive file. If the name is null, then just skip this header.
433 if (*outName == '\0') {
434 for (cc = TAR_BLOCK_SIZE; cc > 0; cc--) {
445 * There is another file in the archive to examine.
446 * Extract the encoded information and check it.
448 mode = getOctal(hp->mode, sizeof(hp->mode));
449 uid = getOctal(hp->uid, sizeof(hp->uid));
450 gid = getOctal(hp->gid, sizeof(hp->gid));
451 size = getOctal(hp->size, sizeof(hp->size));
452 mtime = getOctal(hp->mtime, sizeof(hp->mtime));
453 checkSum = getOctal(hp->checkSum, sizeof(hp->checkSum));
454 major = getOctal(hp->devMajor, sizeof(hp->devMajor));
455 minor = getOctal(hp->devMinor, sizeof(hp->devMinor));
457 if ((mode < 0) || (uid < 0) || (gid < 0) || (size < 0)) {
458 if (badHeader == FALSE)
459 fprintf(stderr, "Bad tar header, skipping\n");
467 skipFileFlag = FALSE;
471 * Check for the file modes.
473 hardLink = ((hp->typeFlag == TAR_TYPE_HARD_LINK) ||
474 (hp->typeFlag == TAR_TYPE_HARD_LINK - '0'));
476 softLink = ((hp->typeFlag == TAR_TYPE_SOFT_LINK) ||
477 (hp->typeFlag == TAR_TYPE_SOFT_LINK - '0'));
480 * Check for a directory.
482 if (outName[strlen(outName) - 1] == '/')
486 * Check for absolute paths in the file.
487 * If we find any, then warn the user and make them relative.
489 if (*outName == '/') {
490 while (*outName == '/')
493 if (warnedRoot == FALSE) {
495 "Absolute path detected, removing leading slashes\n");
502 * See if we want this file to be restored.
503 * If not, then set up to skip it.
505 if (wantFileName(outName, fileCount, fileTable) == FALSE) {
506 if (!hardLink && !softLink && (S_ISREG(mode) || S_ISCHR(mode)
507 || S_ISBLK(mode) || S_ISSOCK(mode)
508 || S_ISFIFO(mode))) {
509 inHeader = (size == 0) ? TRUE : FALSE;
519 * This file is to be handled.
520 * If we aren't extracting then just list information about the file.
522 if (extractFlag == FALSE) {
523 if (verboseFlag == TRUE) {
524 printf("%s %3d/%-d ", modeString(mode), uid, gid);
525 if (S_ISCHR(mode) || S_ISBLK(mode))
526 printf("%4d,%4d %s ", major, minor, timeString(mtime));
528 printf("%9ld %s ", size, timeString(mtime));
530 printf("%s", outName);
533 printf(" (link to \"%s\")", hp->linkName);
535 printf(" (symlink to \"%s\")", hp->linkName);
536 else if (S_ISREG(mode) || S_ISCHR(mode) || S_ISBLK(mode) ||
537 S_ISSOCK(mode) || S_ISFIFO(mode)) {
538 inHeader = (size == 0) ? TRUE : FALSE;
548 * We really want to extract the file.
550 if (verboseFlag == TRUE)
551 printf("x %s\n", outName);
554 if (link(hp->linkName, outName) < 0) {
558 /* Set the file time */
561 utime(outName, &utb);
562 /* Set the file permissions */
563 chown(outName, uid, gid);
564 chmod(outName, mode);
570 if (symlink(hp->linkName, outName) < 0) {
574 /* Try to change ownership of the symlink.
575 * If libs doesn't support that, don't bother.
576 * Changing the pointed-to file is the Wrong Thing(tm).
578 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
579 lchown(outName, uid, gid);
582 /* Do not change permissions or date on symlink,
583 * since it changes the pointed to file instead. duh. */
585 fprintf(stderr, "Cannot create symbolic links\n");
590 /* Set the umask for this process so it doesn't
591 * screw things up. */
595 * If the file is a directory, then just create the path.
598 if (createPath(outName, mode) == TRUE) {
599 /* Set the file time */
602 utime(outName, &utb);
603 /* Set the file permissions */
604 chown(outName, uid, gid);
605 chmod(outName, mode);
612 * There is a file to write.
613 * First create the path to it if necessary with default permissions.
615 createPath(outName, 0777);
617 inHeader = (size == 0) ? TRUE : FALSE;
621 * Start the output file.
623 if (tostdoutFlag == TRUE)
624 outFd = fileno(stdout);
626 if (S_ISCHR(mode) || S_ISBLK(mode) || S_ISSOCK(mode)) {
628 outFd = mknod(outName, mode, makedev(major, minor));
629 } else if (S_ISFIFO(mode)) {
631 outFd = mkfifo(outName, mode);
633 outFd = open(outName, O_WRONLY | O_CREAT | O_TRUNC, mode);
640 /* Set the file time */
643 utime(outName, &utb);
644 /* Set the file permissions */
645 chown(outName, uid, gid);
646 chmod(outName, mode);
651 * If the file is empty, then that's all we need to do.
653 if (size == 0 && (tostdoutFlag == FALSE) && (devFileFlag == FALSE)) {
661 * Handle a data block of some specified size that was read.
663 static void readData(const char *cp, int count)
666 * Reduce the amount of data left in this file.
667 * If there is no more data left, then we need to read
676 * If we aren't extracting files or this file is being
677 * skipped then do nothing more.
679 if (extractFlag == FALSE || skipFileFlag == TRUE)
683 * Write the data to the output file.
685 if (fullWrite(outFd, cp, count) < 0) {
687 if (tostdoutFlag == FALSE) {
696 * Check if we are done writing to the file now.
698 if (dataCc <= 0 && tostdoutFlag == FALSE) {
704 /* Set the file time */
707 utime(outName, &utb);
708 /* Set the file permissions */
709 chown(outName, uid, gid);
710 chmod(outName, mode);
718 * See if the specified file name belongs to one of the specified list
719 * of path prefixes. An empty list implies that all files are wanted.
720 * Returns TRUE if the file is selected.
723 wantFileName(const char *fileName, int fileCount, char **fileTable)
725 const char *pathName;
730 * If there are no files in the list, then the file is wanted.
735 fileLength = strlen(fileName);
738 * Check each of the test paths.
740 while (fileCount-- > 0) {
741 pathName = *fileTable++;
743 pathLength = strlen(pathName);
745 if (fileLength < pathLength)
748 if (memcmp(fileName, pathName, pathLength) != 0)
751 if ((fileLength == pathLength) || (fileName[pathLength] == '/')) {
760 * Read an octal value in a field of the specified width, with optional
761 * spaces on both sides of the number and with an optional null character
762 * at the end. Returns -1 on an illegal format.
764 static long getOctal(const char *cp, int len)
768 while ((len > 0) && (*cp == ' ')) {
773 if ((len == 0) || !isOctal(*cp))
778 while ((len > 0) && isOctal(*cp)) {
779 val = val * 8 + *cp++ - '0';
783 while ((len > 0) && (*cp == ' ')) {
788 if ((len > 0) && *cp)
797 /* From here to the end of the file is the tar writing stuff.
798 * If you do not have BB_FEATURE_TAR_CREATE defined, this will
801 #ifdef BB_FEATURE_TAR_CREATE
804 * Write a tar file containing the specified files.
806 static void writeTarFile(int fileCount, char **fileTable)
811 * Make sure there is at least one file specified.
813 if (fileCount <= 0) {
814 fprintf(stderr, "No files specified to be saved\n");
819 * Create the tar file for writing.
821 if ((tarName == NULL) || !strcmp(tarName, "-")) {
823 tarFd = fileno(stdout);
825 tarFd = open(tarName, O_WRONLY | O_CREAT | O_TRUNC, 0666);
834 * Get the device and inode of the tar file for checking later.
836 if (fstat(tarFd, &statbuf) < 0) {
842 tarDev = statbuf.st_dev;
843 tarInode = statbuf.st_ino;
846 * Append each file name into the archive file.
847 * Follow symbolic links for these top level file names.
849 while (errorFlag == FALSE && (fileCount-- > 0)) {
850 saveFile(*fileTable++, FALSE);
854 * Now write an empty block of zeroes to end the archive.
856 writeTarBlock("", 1);
861 * Close the tar file and check for errors if it was opened.
863 if ((tostdoutFlag == FALSE) && (tarFd >= 0) && (close(tarFd) < 0))
868 * Save one file into the tar file.
869 * If the file is a directory, then this will recursively save all of
870 * the files and directories within the directory. The seeLinks
871 * flag indicates whether or not we want to see symbolic links as
872 * they really are, instead of blindly following them.
874 static void saveFile(const char *fileName, int seeLinks)
879 if (verboseFlag == TRUE)
880 printf("a %s\n", fileName);
883 * Check that the file name will fit in the header.
885 if (strlen(fileName) >= TAR_NAME_SIZE) {
886 fprintf(stderr, "%s: File name is too long\n", fileName);
892 * Find out about the file.
895 if (seeLinks == TRUE)
896 status = lstat(fileName, &statbuf);
899 status = stat(fileName, &statbuf);
908 * Make sure we aren't trying to save our file into itself.
910 if ((statbuf.st_dev == tarDev) && (statbuf.st_ino == tarInode)) {
911 fprintf(stderr, "Skipping saving of archive file itself\n");
917 * Check the type of file.
919 mode = statbuf.st_mode;
922 saveDirectory(fileName, &statbuf);
927 saveRegularFile(fileName, &statbuf);
932 /* Some day add support for tarring these up... but not today. :) */
933 // if (S_ISLNK(mode) || S_ISFIFO(mode) || S_ISBLK(mode) || S_ISCHR (mode) ) {
934 // fprintf (stderr, "%s: This version of tar can't store this type of file\n", fileName);
938 * The file is a strange type of file, ignore it.
940 fprintf(stderr, "%s: not a directory or regular file\n", fileName);
945 * Save a regular file to the tar file.
948 saveRegularFile(const char *fileName, const struct stat *statbuf)
955 char data[TAR_BLOCK_SIZE * 16];
958 * Open the file for reading.
960 fileFd = open(fileName, O_RDONLY);
969 * Write out the header for the file.
971 writeHeader(fileName, statbuf);
974 * Write the data blocks of the file.
975 * We must be careful to write the amount of data that the stat
976 * buffer indicated, even if the file has changed size. Otherwise
977 * the tar file will be incorrect.
979 fullDataCount = statbuf->st_size;
982 while (fullDataCount > 0) {
984 * Get the amount to write this iteration which is
985 * the minumum of the amount left to write and the
988 dataCount = sizeof(data);
990 if (dataCount > fullDataCount)
991 dataCount = (int) fullDataCount;
994 * Read the data from the file if we haven't seen the
999 if (sawEof == FALSE) {
1000 cc = fullRead(fileFd, data, dataCount);
1005 (void) close(fileFd);
1012 * If the file ended too soon, complain and set
1013 * a flag so we will zero fill the rest of it.
1015 if (cc < dataCount) {
1016 fprintf(stderr, "%s: Short read - zero filling", fileName);
1023 * Zero fill the rest of the data if necessary.
1026 memset(data + cc, 0, dataCount - cc);
1029 * Write the buffer to the TAR file.
1031 writeTarBlock(data, dataCount);
1033 fullDataCount -= dataCount;
1039 if ((tostdoutFlag == FALSE) && close(fileFd) < 0)
1040 fprintf(stderr, "%s: close: %s\n", fileName, strerror(errno));
1045 * Save a directory and all of its files to the tar file.
1047 static void saveDirectory(const char *dirName, const struct stat *statbuf)
1050 struct dirent *entry;
1052 char fullName[PATH_MAX + 1];
1055 * Construct the directory name as used in the tar file by appending
1056 * a slash character to it.
1058 strcpy(fullName, dirName);
1059 strcat(fullName, "/");
1062 * Write out the header for the directory entry.
1064 writeHeader(fullName, statbuf);
1067 * Open the directory.
1069 dir = opendir(dirName);
1072 fprintf(stderr, "Cannot read directory \"%s\": %s\n",
1073 dirName, strerror(errno));
1079 * See if a slash is needed.
1081 needSlash = (*dirName && (dirName[strlen(dirName) - 1] != '/'));
1084 * Read all of the directory entries and check them,
1085 * except for the current and parent directory entries.
1087 while (errorFlag == FALSE && ((entry = readdir(dir)) != NULL)) {
1088 if ((strcmp(entry->d_name, ".") == 0) ||
1089 (strcmp(entry->d_name, "..") == 0)) {
1094 * Build the full path name to the file.
1096 strcpy(fullName, dirName);
1099 strcat(fullName, "/");
1101 strcat(fullName, entry->d_name);
1104 * Write this file to the tar file, noticing whether or not
1105 * the file is a symbolic link.
1107 saveFile(fullName, TRUE);
1111 * All done, close the directory.
1118 * Write a tar header for the specified file name and status.
1119 * It is assumed that the file name fits.
1121 static void writeHeader(const char *fileName, const struct stat *statbuf)
1124 const unsigned char *cp;
1129 * Zero the header block in preparation for filling it in.
1131 memset((char *) &header, 0, sizeof(header));
1134 * Fill in the header.
1136 strcpy(header.name, fileName);
1138 strncpy(header.magic, TAR_MAGIC, sizeof(header.magic));
1139 strncpy(header.version, TAR_VERSION, sizeof(header.version));
1141 putOctal(header.mode, sizeof(header.mode), statbuf->st_mode & 0777);
1142 putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
1143 putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
1144 putOctal(header.size, sizeof(header.size), statbuf->st_size);
1145 putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
1147 header.typeFlag = TAR_TYPE_REGULAR;
1150 * Calculate and store the checksum.
1151 * This is the sum of all of the bytes of the header,
1152 * with the checksum field itself treated as blanks.
1154 memset(header.checkSum, ' ', sizeof(header.checkSum));
1156 cp = (const unsigned char *) &header;
1157 len = sizeof(header);
1163 putOctal(header.checkSum, sizeof(header.checkSum), checkSum);
1166 * Write the tar header.
1168 writeTarBlock((const char *) &header, sizeof(header));
1173 * Write data to one or more blocks of the tar file.
1174 * The data is always padded out to a multiple of TAR_BLOCK_SIZE.
1175 * The errorFlag static variable is set on an error.
1177 static void writeTarBlock(const char *buf, int len)
1181 char fullBlock[TAR_BLOCK_SIZE];
1184 * If we had a write error before, then do nothing more.
1186 if (errorFlag == TRUE)
1190 * Get the amount of complete and partial blocks.
1192 partialLength = len % TAR_BLOCK_SIZE;
1193 completeLength = len - partialLength;
1196 * Write all of the complete blocks.
1198 if ((completeLength > 0) && !fullWrite(tarFd, buf, completeLength)) {
1207 * If there are no partial blocks left, we are done.
1209 if (partialLength == 0)
1213 * Copy the partial data into a complete block, and pad the rest
1214 * of it with zeroes.
1216 memcpy(fullBlock, buf + completeLength, partialLength);
1217 memset(fullBlock + partialLength, 0, TAR_BLOCK_SIZE - partialLength);
1220 * Write the last complete block.
1222 if (!fullWrite(tarFd, fullBlock, TAR_BLOCK_SIZE)) {
1231 * Put an octal string into the specified buffer.
1232 * The number is zero and space padded and possibly null padded.
1233 * Returns TRUE if successful.
1235 static int putOctal(char *cp, int len, long value)
1239 char tempBuffer[32];
1242 * Create a string of the specified length with an initial space,
1243 * leading zeroes and the octal number, and a trailing null.
1245 tempString = tempBuffer;
1247 sprintf(tempString, " %0*lo", len - 2, value);
1249 tempLength = strlen(tempString) + 1;
1252 * If the string is too large, suppress the leading space.
1254 if (tempLength > len) {
1260 * If the string is still too large, suppress the trailing null.
1262 if (tempLength > len)
1266 * If the string is still too large, fail.
1268 if (tempLength > len)
1272 * Copy the string to the field.
1274 memcpy(cp, tempString, len);