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