archival/tar.c

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