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 #include <fnmatch.h>
  46 #include "libbb.h"
  47 #include "archive.h"
  48 /* FIXME: Stop using this non-standard feature */
  49 #ifndef FNM_LEADING_DIR
  50 # define FNM_LEADING_DIR 0
  51 #endif
  52
  53
  54 //#define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
  55 #define DBG(...) ((void)0)
  56
  57
  58 #define block_buf bb_common_bufsiz1
  59
  60
  61 #if !ENABLE_FEATURE_SEAMLESS_GZ && !ENABLE_FEATURE_SEAMLESS_BZ2
  62 /* Do not pass gzip flag to writeTarFile() */
  63 #define writeTarFile(tar_fd, verboseFlag, dereferenceFlag, include, exclude, gzip) \
  64         writeTarFile(tar_fd, verboseFlag, dereferenceFlag, include, exclude)
  65 #endif
  66
  67
  68 #if ENABLE_FEATURE_TAR_CREATE
  69
  70 /*
  71 ** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
  72 ** the only functions that deal with the HardLinkInfo structure.
  73 ** Even these functions use the xxxHardLinkInfo() functions.
  74 */
  75 typedef struct HardLinkInfo {
  76         struct HardLinkInfo *next; /* Next entry in list */
  77         dev_t dev;                 /* Device number */
  78         ino_t ino;                 /* Inode number */
  79 //      short linkCount;           /* (Hard) Link Count */
  80         char name[1];              /* Start of filename (must be last) */
  81 } HardLinkInfo;
  82
  83 /* Some info to be carried along when creating a new tarball */
  84 typedef struct TarBallInfo {
  85         int tarFd;                      /* Open-for-write file descriptor
  86                                          * for the tarball */
  87         int verboseFlag;                /* Whether to print extra stuff or not */
  88         const llist_t *excludeList;     /* List of files to not include */
  89         HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
  90         HardLinkInfo *hlInfo;           /* Hard Link Info for the current file */
  91 //TODO: save only st_dev + st_ino
  92         struct stat tarFileStatBuf;     /* Stat info for the tarball, letting
  93                                          * us know the inode and device that the
  94                                          * tarball lives, so we can avoid trying
  95                                          * to include the tarball into itself */
  96 } TarBallInfo;
  97
  98 /* A nice enum with all the possible tar file content types */
  99 enum {
 100         REGTYPE = '0',          /* regular file */
 101         REGTYPE0 = '\0',        /* regular file (ancient bug compat) */
 102         LNKTYPE = '1',          /* hard link */
 103         SYMTYPE = '2',          /* symbolic link */
 104         CHRTYPE = '3',          /* character special */
 105         BLKTYPE = '4',          /* block special */
 106         DIRTYPE = '5',          /* directory */
 107         FIFOTYPE = '6',         /* FIFO special */
 108         CONTTYPE = '7',         /* reserved */
 109         GNULONGLINK = 'K',      /* GNU long (>100 chars) link name */
 110         GNULONGNAME = 'L',      /* GNU long (>100 chars) file name */
 111 };
 112
 113 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
 114 static void addHardLinkInfo(HardLinkInfo **hlInfoHeadPtr,
 115                                         struct stat *statbuf,
 116                                         const char *fileName)
 117 {
 118         /* Note: hlInfoHeadPtr can never be NULL! */
 119         HardLinkInfo *hlInfo;
 120
 121         hlInfo = xmalloc(sizeof(HardLinkInfo) + strlen(fileName));
 122         hlInfo->next = *hlInfoHeadPtr;
 123         *hlInfoHeadPtr = hlInfo;
 124         hlInfo->dev = statbuf->st_dev;
 125         hlInfo->ino = statbuf->st_ino;
 126 //      hlInfo->linkCount = statbuf->st_nlink;
 127         strcpy(hlInfo->name, fileName);
 128 }
 129
 130 static void freeHardLinkInfo(HardLinkInfo **hlInfoHeadPtr)
 131 {
 132         HardLinkInfo *hlInfo;
 133         HardLinkInfo *hlInfoNext;
 134
 135         if (hlInfoHeadPtr) {
 136                 hlInfo = *hlInfoHeadPtr;
 137                 while (hlInfo) {
 138                         hlInfoNext = hlInfo->next;
 139                         free(hlInfo);
 140                         hlInfo = hlInfoNext;
 141                 }
 142                 *hlInfoHeadPtr = NULL;
 143         }
 144 }
 145
 146 /* Might be faster (and bigger) if the dev/ino were stored in numeric order ;) */
 147 static HardLinkInfo *findHardLinkInfo(HardLinkInfo *hlInfo, struct stat *statbuf)
 148 {
 149         while (hlInfo) {
 150                 if (statbuf->st_ino == hlInfo->ino
 151                  && statbuf->st_dev == hlInfo->dev
 152                 ) {
 153                         DBG("found hardlink:'%s'", hlInfo->name);
 154                         break;
 155                 }
 156                 hlInfo = hlInfo->next;
 157         }
 158         return hlInfo;
 159 }
 160
 161 /* Put an octal string into the specified buffer.
 162  * The number is zero padded and possibly null terminated.
 163  * Stores low-order bits only if whole value does not fit. */
 164 static void putOctal(char *cp, int len, off_t value)
 165 {
 166         char tempBuffer[sizeof(off_t)*3 + 1];
 167         char *tempString = tempBuffer;
 168         int width;
 169
 170         width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
 171         tempString += (width - len);
 172
 173         /* If string has leading zeroes, we can drop one */
 174         /* and field will have trailing '\0' */
 175         /* (increases chances of compat with other tars) */
 176         if (tempString[0] == '0')
 177                 tempString++;
 178
 179         /* Copy the string to the field */
 180         memcpy(cp, tempString, len);
 181 }
 182 #define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
 183
 184 static void chksum_and_xwrite(int fd, struct tar_header_t* hp)
 185 {
 186         /* POSIX says that checksum is done on unsigned bytes
 187          * (Sun and HP-UX gets it wrong... more details in
 188          * GNU tar source) */
 189         const unsigned char *cp;
 190         int chksum, size;
 191
 192         strcpy(hp->magic, "ustar  ");
 193
 194         /* Calculate and store the checksum (i.e., the sum of all of the bytes of
 195          * the header).  The checksum field must be filled with blanks for the
 196          * calculation.  The checksum field is formatted differently from the
 197          * other fields: it has 6 digits, a null, then a space -- rather than
 198          * digits, followed by a null like the other fields... */
 199         memset(hp->chksum, ' ', sizeof(hp->chksum));
 200         cp = (const unsigned char *) hp;
 201         chksum = 0;
 202         size = sizeof(*hp);
 203         do { chksum += *cp++; } while (--size);
 204         putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);
 205
 206         /* Now write the header out to disk */
 207         xwrite(fd, hp, sizeof(*hp));
 208 }
 209
 210 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 211 static void writeLongname(int fd, int type, const char *name, int dir)
 212 {
 213         static const struct {
 214                 char mode[8];             /* 100-107 */
 215                 char uid[8];              /* 108-115 */
 216                 char gid[8];              /* 116-123 */
 217                 char size[12];            /* 124-135 */
 218                 char mtime[12];           /* 136-147 */
 219         } prefilled = {
 220                 "0000000",
 221                 "0000000",
 222                 "0000000",
 223                 "00000000000",
 224                 "00000000000",
 225         };
 226         struct tar_header_t header;
 227         int size;
 228
 229         dir = !!dir; /* normalize: 0/1 */
 230         size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
 231         /* + dir: account for possible '/' */
 232
 233         memset(&header, 0, sizeof(header));
 234         strcpy(header.name, "././@LongLink");
 235         memcpy(header.mode, prefilled.mode, sizeof(prefilled));
 236         PUT_OCTAL(header.size, size);
 237         header.typeflag = type;
 238         chksum_and_xwrite(fd, &header);
 239
 240         /* Write filename[/] and pad the block. */
 241         /* dir=0: writes 'name<NUL>', pads */
 242         /* dir=1: writes 'name', writes '/<NUL>', pads */
 243         dir *= 2;
 244         xwrite(fd, name, size - dir);
 245         xwrite(fd, "/", dir);
 246         size = (-size) & (TAR_BLOCK_SIZE-1);
 247         memset(&header, 0, size);
 248         xwrite(fd, &header, size);
 249 }
 250 #endif
 251
 252 /* Write out a tar header for the specified file/directory/whatever */
 253 static int writeTarHeader(struct TarBallInfo *tbInfo,
 254                 const char *header_name, const char *fileName, struct stat *statbuf)
 255 {
 256         struct tar_header_t header;
 257
 258         memset(&header, 0, sizeof(header));
 259
 260         strncpy(header.name, header_name, sizeof(header.name));
 261
 262         /* POSIX says to mask mode with 07777. */
 263         PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
 264         PUT_OCTAL(header.uid, statbuf->st_uid);
 265         PUT_OCTAL(header.gid, statbuf->st_gid);
 266         memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
 267         PUT_OCTAL(header.mtime, statbuf->st_mtime);
 268
 269         /* Enter the user and group names */
 270         safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
 271         safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
 272
 273         if (tbInfo->hlInfo) {
 274                 /* This is a hard link */
 275                 header.typeflag = LNKTYPE;
 276                 strncpy(header.linkname, tbInfo->hlInfo->name,
 277                                 sizeof(header.linkname));
 278 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 279                 /* Write out long linkname if needed */
 280                 if (header.linkname[sizeof(header.linkname)-1])
 281                         writeLongname(tbInfo->tarFd, GNULONGLINK,
 282                                         tbInfo->hlInfo->name, 0);
 283 #endif
 284         } else if (S_ISLNK(statbuf->st_mode)) {
 285                 char *lpath = xmalloc_readlink_or_warn(fileName);
 286                 if (!lpath)
 287                         return FALSE;
 288                 header.typeflag = SYMTYPE;
 289                 strncpy(header.linkname, lpath, sizeof(header.linkname));
 290 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 291                 /* Write out long linkname if needed */
 292                 if (header.linkname[sizeof(header.linkname)-1])
 293                         writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
 294 #else
 295                 /* If it is larger than 100 bytes, bail out */
 296                 if (header.linkname[sizeof(header.linkname)-1]) {
 297                         free(lpath);
 298                         bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 299                         return FALSE;
 300                 }
 301 #endif
 302                 free(lpath);
 303         } else if (S_ISDIR(statbuf->st_mode)) {
 304                 header.typeflag = DIRTYPE;
 305                 /* Append '/' only if there is a space for it */
 306                 if (!header.name[sizeof(header.name)-1])
 307                         header.name[strlen(header.name)] = '/';
 308         } else if (S_ISCHR(statbuf->st_mode)) {
 309                 header.typeflag = CHRTYPE;
 310                 PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
 311                 PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 312         } else if (S_ISBLK(statbuf->st_mode)) {
 313                 header.typeflag = BLKTYPE;
 314                 PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
 315                 PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 316         } else if (S_ISFIFO(statbuf->st_mode)) {
 317                 header.typeflag = FIFOTYPE;
 318         } else if (S_ISREG(statbuf->st_mode)) {
 319                 if (sizeof(statbuf->st_size) > 4
 320                  && statbuf->st_size > (off_t)0777777777777LL
 321                 ) {
 322                         bb_error_msg_and_die("can't store file '%s' "
 323                                 "of size %"OFF_FMT"u, aborting",
 324                                 fileName, statbuf->st_size);
 325                 }
 326                 header.typeflag = REGTYPE;
 327                 PUT_OCTAL(header.size, statbuf->st_size);
 328         } else {
 329                 bb_error_msg("%s: unknown file type", fileName);
 330                 return FALSE;
 331         }
 332
 333 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 334         /* Write out long name if needed */
 335         /* (we, like GNU tar, output long linkname *before* long name) */
 336         if (header.name[sizeof(header.name)-1])
 337                 writeLongname(tbInfo->tarFd, GNULONGNAME,
 338                                 header_name, S_ISDIR(statbuf->st_mode));
 339 #endif
 340
 341         /* Now write the header out to disk */
 342         chksum_and_xwrite(tbInfo->tarFd, &header);
 343
 344         /* Now do the verbose thing (or not) */
 345         if (tbInfo->verboseFlag) {
 346                 FILE *vbFd = stdout;
 347
 348                 /* If archive goes to stdout, verbose goes to stderr */
 349                 if (tbInfo->tarFd == STDOUT_FILENO)
 350                         vbFd = stderr;
 351                 /* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
 352                 /* We don't have such excesses here: for us "v" == "vv" */
 353                 /* '/' is probably a GNUism */
 354                 fprintf(vbFd, "%s%s\n", header_name,
 355                                 S_ISDIR(statbuf->st_mode) ? "/" : "");
 356         }
 357
 358         return TRUE;
 359 }
 360
 361 #if ENABLE_FEATURE_TAR_FROM
 362 static int exclude_file(const llist_t *excluded_files, const char *file)
 363 {
 364         while (excluded_files) {
 365                 if (excluded_files->data[0] == '/') {
 366                         if (fnmatch(excluded_files->data, file,
 367                                         FNM_PATHNAME | FNM_LEADING_DIR) == 0)
 368                                 return 1;
 369                 } else {
 370                         const char *p;
 371
 372                         for (p = file; p[0] != '\0'; p++) {
 373                                 if ((p == file || p[-1] == '/')
 374                                  && p[0] != '/'
 375                                  && fnmatch(excluded_files->data, p,
 376                                                 FNM_PATHNAME | FNM_LEADING_DIR) == 0
 377                                 ) {
 378                                         return 1;
 379                                 }
 380                         }
 381                 }
 382                 excluded_files = excluded_files->link;
 383         }
 384
 385         return 0;
 386 }
 387 #else
 388 # define exclude_file(excluded_files, file) 0
 389 #endif
 390
 391 static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statbuf,
 392                         void *userData, int depth UNUSED_PARAM)
 393 {
 394         struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
 395         const char *header_name;
 396         int inputFileFd = -1;
 397
 398         DBG("writeFileToTarball('%s')", fileName);
 399
 400         /* Strip leading '/' (must be before memorizing hardlink's name) */
 401         header_name = fileName;
 402         while (header_name[0] == '/') {
 403                 static smallint warned;
 404
 405                 if (!warned) {
 406                         bb_error_msg("removing leading '/' from member names");
 407                         warned = 1;
 408                 }
 409                 header_name++;
 410         }
 411
 412         if (header_name[0] == '\0')
 413                 return TRUE;
 414
 415         /* It is against the rules to archive a socket */
 416         if (S_ISSOCK(statbuf->st_mode)) {
 417                 bb_error_msg("%s: socket ignored", fileName);
 418                 return TRUE;
 419         }
 420
 421         /*
 422          * Check to see if we are dealing with a hard link.
 423          * If so -
 424          * Treat the first occurance of a given dev/inode as a file while
 425          * treating any additional occurances as hard links.  This is done
 426          * by adding the file information to the HardLinkInfo linked list.
 427          */
 428         tbInfo->hlInfo = NULL;
 429         if (!S_ISDIR(statbuf->st_mode) && statbuf->st_nlink > 1) {
 430                 DBG("'%s': st_nlink > 1", header_name);
 431                 tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
 432                 if (tbInfo->hlInfo == NULL) {
 433                         DBG("'%s': addHardLinkInfo", header_name);
 434                         addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, header_name);
 435                 }
 436         }
 437
 438         /* It is a bad idea to store the archive we are in the process of creating,
 439          * so check the device and inode to be sure that this particular file isn't
 440          * the new tarball */
 441         if (tbInfo->tarFileStatBuf.st_dev == statbuf->st_dev
 442          && tbInfo->tarFileStatBuf.st_ino == statbuf->st_ino
 443         ) {
 444                 bb_error_msg("%s: file is the archive; skipping", fileName);
 445                 return TRUE;
 446         }
 447
 448         if (exclude_file(tbInfo->excludeList, header_name))
 449                 return SKIP;
 450
 451 #if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 452         if (strlen(header_name) >= NAME_SIZE) {
 453                 bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 454                 return TRUE;
 455         }
 456 #endif
 457
 458         /* Is this a regular file? */
 459         if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
 460                 /* open the file we want to archive, and make sure all is well */
 461                 inputFileFd = open_or_warn(fileName, O_RDONLY);
 462                 if (inputFileFd < 0) {
 463                         return FALSE;
 464                 }
 465         }
 466
 467         /* Add an entry to the tarball */
 468         if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
 469                 return FALSE;
 470         }
 471
 472         /* If it was a regular file, write out the body */
 473         if (inputFileFd >= 0) {
 474                 size_t readSize;
 475                 /* Write the file to the archive. */
 476                 /* We record size into header first, */
 477                 /* and then write out file. If file shrinks in between, */
 478                 /* tar will be corrupted. So we don't allow for that. */
 479                 /* NB: GNU tar 1.16 warns and pads with zeroes */
 480                 /* or even seeks back and updates header */
 481                 bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
 482                 ////off_t readSize;
 483                 ////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
 484                 ////if (readSize != statbuf->st_size && readSize >= 0) {
 485                 ////    bb_error_msg_and_die("short read from %s, aborting", fileName);
 486                 ////}
 487
 488                 /* Check that file did not grow in between? */
 489                 /* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
 490
 491                 close(inputFileFd);
 492
 493                 /* Pad the file up to the tar block size */
 494                 /* (a few tricks here in the name of code size) */
 495                 readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
 496                 memset(block_buf, 0, readSize);
 497                 xwrite(tbInfo->tarFd, block_buf, readSize);
 498         }
 499
 500         return TRUE;
 501 }
 502
 503 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 504 # if !(ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2)
 505 #  define vfork_compressor(tar_fd, gzip) vfork_compressor(tar_fd)
 506 # endif
 507 /* Don't inline: vfork scares gcc and pessimizes code */
 508 static void NOINLINE vfork_compressor(int tar_fd, int gzip)
 509 {
 510         pid_t gzipPid;
 511 # if ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2
 512         const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
 513 # elif ENABLE_FEATURE_SEAMLESS_GZ
 514         const char *zip_exec = "gzip";
 515 # else /* only ENABLE_FEATURE_SEAMLESS_BZ2 */
 516         const char *zip_exec = "bzip2";
 517 # endif
 518         // On Linux, vfork never unpauses parent early, although standard
 519         // allows for that. Do we want to waste bytes checking for it?
 520 # define WAIT_FOR_CHILD 0
 521         volatile int vfork_exec_errno = 0;
 522         struct fd_pair gzipDataPipe;
 523 # if WAIT_FOR_CHILD
 524         struct fd_pair gzipStatusPipe;
 525         xpiped_pair(gzipStatusPipe);
 526 # endif
 527         xpiped_pair(gzipDataPipe);
 528
 529         signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
 530
 531 # if defined(__GNUC__) && __GNUC__
 532         /* Avoid vfork clobbering */
 533         (void) &zip_exec;
 534 # endif
 535
 536         gzipPid = xvfork();
 537
 538         if (gzipPid == 0) {
 539                 /* child */
 540                 /* NB: close _first_, then move fds! */
 541                 close(gzipDataPipe.wr);
 542 # if WAIT_FOR_CHILD
 543                 close(gzipStatusPipe.rd);
 544                 /* gzipStatusPipe.wr will close only on exec -
 545                  * parent waits for this close to happen */
 546                 fcntl(gzipStatusPipe.wr, F_SETFD, FD_CLOEXEC);
 547 # endif
 548                 xmove_fd(gzipDataPipe.rd, 0);
 549                 xmove_fd(tar_fd, 1);
 550                 /* exec gzip/bzip2 program/applet */
 551                 BB_EXECLP(zip_exec, zip_exec, "-f", NULL);
 552                 vfork_exec_errno = errno;
 553                 _exit(EXIT_FAILURE);
 554         }
 555
 556         /* parent */
 557         xmove_fd(gzipDataPipe.wr, tar_fd);
 558         close(gzipDataPipe.rd);
 559 # if WAIT_FOR_CHILD
 560         close(gzipStatusPipe.wr);
 561         while (1) {
 562                 char buf;
 563                 int n;
 564
 565                 /* Wait until child execs (or fails to) */
 566                 n = full_read(gzipStatusPipe.rd, &buf, 1);
 567                 if (n < 0 /* && errno == EAGAIN */)
 568                         continue;       /* try it again */
 569         }
 570         close(gzipStatusPipe.rd);
 571 # endif
 572         if (vfork_exec_errno) {
 573                 errno = vfork_exec_errno;
 574                 bb_perror_msg_and_die("can't execute '%s'", zip_exec);
 575         }
 576 }
 577 #endif /* ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2 */
 578
 579
 580 /* gcc 4.2.1 inlines it, making code bigger */
 581 static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
 582         int dereferenceFlag, const llist_t *include,
 583         const llist_t *exclude, int gzip)
 584 {
 585         int errorFlag = FALSE;
 586         struct TarBallInfo tbInfo;
 587
 588         tbInfo.hlInfoHead = NULL;
 589         tbInfo.tarFd = tar_fd;
 590         tbInfo.verboseFlag = verboseFlag;
 591
 592         /* Store the stat info for the tarball's file, so
 593          * can avoid including the tarball into itself....  */
 594         xfstat(tbInfo.tarFd, &tbInfo.tarFileStatBuf, "can't stat tar file");
 595
 596 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 597         if (gzip)
 598                 vfork_compressor(tbInfo.tarFd, gzip);
 599 #endif
 600
 601         tbInfo.excludeList = exclude;
 602
 603         /* Read the directory/files and iterate over them one at a time */
 604         while (include) {
 605                 if (!recursive_action(include->data, ACTION_RECURSE |
 606                                 (dereferenceFlag ? ACTION_FOLLOWLINKS : 0),
 607                                 writeFileToTarball, writeFileToTarball, &tbInfo, 0)
 608                 ) {
 609                         errorFlag = TRUE;
 610                 }
 611                 include = include->link;
 612         }
 613         /* Write two empty blocks to the end of the archive */
 614         memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
 615         xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
 616
 617         /* To be pedantically correct, we would check if the tarball
 618          * is smaller than 20 tar blocks, and pad it if it was smaller,
 619          * but that isn't necessary for GNU tar interoperability, and
 620          * so is considered a waste of space */
 621
 622         /* Close so the child process (if any) will exit */
 623         close(tbInfo.tarFd);
 624
 625         /* Hang up the tools, close up shop, head home */
 626         if (ENABLE_FEATURE_CLEAN_UP)
 627                 freeHardLinkInfo(&tbInfo.hlInfoHead);
 628
 629         if (errorFlag)
 630                 bb_error_msg("error exit delayed from previous errors");
 631
 632 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 633         if (gzip) {
 634                 int status;
 635                 if (safe_waitpid(-1, &status, 0) == -1)
 636                         bb_perror_msg("waitpid");
 637                 else if (!WIFEXITED(status) || WEXITSTATUS(status))
 638                         /* gzip was killed or has exited with nonzero! */
 639                         errorFlag = TRUE;
 640         }
 641 #endif
 642         return errorFlag;
 643 }
 644 #else
 645 int writeTarFile(int tar_fd, int verboseFlag,
 646         int dereferenceFlag, const llist_t *include,
 647         const llist_t *exclude, int gzip);
 648 #endif /* FEATURE_TAR_CREATE */
 649
 650 #if ENABLE_FEATURE_TAR_FROM
 651 static llist_t *append_file_list_to_list(llist_t *list)
 652 {
 653         FILE *src_stream;
 654         char *line;
 655         llist_t *newlist = NULL;
 656
 657         while (list) {
 658                 src_stream = xfopen_for_read(llist_pop(&list));
 659                 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
 660                         /* kill trailing '/' unless the string is just "/" */
 661                         char *cp = last_char_is(line, '/');
 662                         if (cp > line)
 663                                 *cp = '\0';
 664                         llist_add_to(&newlist, line);
 665                 }
 666                 fclose(src_stream);
 667         }
 668         return newlist;
 669 }
 670 #else
 671 # define append_file_list_to_list(x) 0
 672 #endif
 673
 674 #if ENABLE_FEATURE_SEAMLESS_Z
 675 static char FAST_FUNC get_header_tar_Z(archive_handle_t *archive_handle)
 676 {
 677         /* Can't lseek over pipes */
 678         archive_handle->seek = seek_by_read;
 679
 680         /* do the decompression, and cleanup */
 681         if (xread_char(archive_handle->src_fd) != 0x1f
 682          || xread_char(archive_handle->src_fd) != 0x9d
 683         ) {
 684                 bb_error_msg_and_die("invalid magic");
 685         }
 686
 687         open_transformer(archive_handle->src_fd, unpack_Z_stream, "uncompress");
 688         archive_handle->offset = 0;
 689         while (get_header_tar(archive_handle) == EXIT_SUCCESS)
 690                 continue;
 691
 692         /* Can only do one file at a time */
 693         return EXIT_FAILURE;
 694 }
 695 #else
 696 # define get_header_tar_Z NULL
 697 #endif
 698
 699 #ifdef CHECK_FOR_CHILD_EXITCODE
 700 /* Looks like it isn't needed - tar detects malformed (truncated)
 701  * archive if e.g. bunzip2 fails */
 702 static int child_error;
 703
 704 static void handle_SIGCHLD(int status)
 705 {
 706         /* Actually, 'status' is a signo. We reuse it for other needs */
 707
 708         /* Wait for any child without blocking */
 709         if (wait_any_nohang(&status) < 0)
 710                 /* wait failed?! I'm confused... */
 711                 return;
 712
 713         if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
 714                 /* child exited with 0 */
 715                 return;
 716         /* Cannot happen?
 717         if (!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
 718         child_error = 1;
 719 }
 720 #endif
 721
 722 //usage:#define tar_trivial_usage
 723 //usage:        "-[" IF_FEATURE_TAR_CREATE("c") "xt"
 724 //usage:        IF_FEATURE_SEAMLESS_Z("Z")
 725 //usage:        IF_FEATURE_SEAMLESS_GZ("z")
 726 //usage:        IF_FEATURE_SEAMLESS_BZ2("j")
 727 //usage:        IF_FEATURE_SEAMLESS_LZMA("a")
 728 //usage:        IF_FEATURE_TAR_CREATE("h")
 729 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 730 //usage:        "vO] "
 731 //usage:        IF_FEATURE_TAR_FROM("[-X FILE] [-T FILE] ")
 732 //usage:        "[-f TARFILE] [-C DIR] [FILE]..."
 733 //usage:#define tar_full_usage "\n\n"
 734 //usage:        IF_FEATURE_TAR_CREATE("Create, extract, ")
 735 //usage:        IF_NOT_FEATURE_TAR_CREATE("Extract ")
 736 //usage:        "or list files from a tar file\n"
 737 //usage:     "\nOperation:"
 738 //usage:        IF_FEATURE_TAR_CREATE(
 739 //usage:     "\n        c       Create"
 740 //usage:        )
 741 //usage:     "\n        x       Extract"
 742 //usage:     "\n        t       List"
 743 //usage:     "\nOptions:"
 744 //usage:     "\n        f       Name of TARFILE ('-' for stdin/out)"
 745 //usage:     "\n        C       Change to DIR before operation"
 746 //usage:     "\n        v       Verbose"
 747 //usage:        IF_FEATURE_SEAMLESS_Z(
 748 //usage:     "\n        Z       (De)compress using compress"
 749 //usage:        )
 750 //usage:        IF_FEATURE_SEAMLESS_GZ(
 751 //usage:     "\n        z       (De)compress using gzip"
 752 //usage:        )
 753 //usage:        IF_FEATURE_SEAMLESS_BZ2(
 754 //usage:     "\n        j       (De)compress using bzip2"
 755 //usage:        )
 756 //usage:        IF_FEATURE_SEAMLESS_LZMA(
 757 //usage:     "\n        a       (De)compress using lzma"
 758 //usage:        )
 759 //usage:     "\n        O       Extract to stdout"
 760 //usage:        IF_FEATURE_TAR_CREATE(
 761 //usage:     "\n        h       Follow symlinks"
 762 //usage:        )
 763 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME(
 764 //usage:     "\n        m       Don't restore mtime"
 765 //usage:        )
 766 //usage:        IF_FEATURE_TAR_FROM(
 767 //usage:        IF_FEATURE_TAR_LONG_OPTIONS(
 768 //usage:     "\n        exclude File to exclude"
 769 //usage:        )
 770 //usage:     "\n        X       File with names to exclude"
 771 //usage:     "\n        T       File with names to include"
 772 //usage:        )
 773 //usage:
 774 //usage:#define tar_example_usage
 775 //usage:       "$ zcat /tmp/tarball.tar.gz | tar -xf -\n"
 776 //usage:       "$ tar -cf /tmp/tarball.tar /usr/local\n"
 777
 778 // Supported but aren't in --help:
 779 //      o       no-same-owner
 780 //      p       same-permissions
 781 //      k       keep-old
 782 //      numeric-owner
 783 //      no-same-permissions
 784 //      overwrite
 785 //IF_FEATURE_TAR_TO_COMMAND(
 786 //      to-command
 787 //)
 788
 789 enum {
 790         OPTBIT_KEEP_OLD = 8,
 791         IF_FEATURE_TAR_CREATE(   OPTBIT_CREATE      ,)
 792         IF_FEATURE_TAR_CREATE(   OPTBIT_DEREFERENCE ,)
 793         IF_FEATURE_SEAMLESS_BZ2( OPTBIT_BZIP2       ,)
 794         IF_FEATURE_SEAMLESS_LZMA(OPTBIT_LZMA        ,)
 795         IF_FEATURE_TAR_FROM(     OPTBIT_INCLUDE_FROM,)
 796         IF_FEATURE_TAR_FROM(     OPTBIT_EXCLUDE_FROM,)
 797         IF_FEATURE_SEAMLESS_GZ(  OPTBIT_GZIP        ,)
 798         IF_FEATURE_SEAMLESS_Z(   OPTBIT_COMPRESS    ,) // 16th bit
 799         IF_FEATURE_TAR_NOPRESERVE_TIME(OPTBIT_NOPRESERVE_TIME,)
 800 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 801         IF_FEATURE_TAR_TO_COMMAND(OPTBIT_2COMMAND   ,)
 802         OPTBIT_NUMERIC_OWNER,
 803         OPTBIT_NOPRESERVE_PERM,
 804         OPTBIT_OVERWRITE,
 805 #endif
 806         OPT_TEST         = 1 << 0, // t
 807         OPT_EXTRACT      = 1 << 1, // x
 808         OPT_BASEDIR      = 1 << 2, // C
 809         OPT_TARNAME      = 1 << 3, // f
 810         OPT_2STDOUT      = 1 << 4, // O
 811         OPT_NOPRESERVE_OWNER = 1 << 5, // o == no-same-owner
 812         OPT_P            = 1 << 6, // p
 813         OPT_VERBOSE      = 1 << 7, // v
 814         OPT_KEEP_OLD     = 1 << 8, // k
 815         OPT_CREATE       = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_CREATE      )) + 0, // c
 816         OPT_DEREFERENCE  = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_DEREFERENCE )) + 0, // h
 817         OPT_BZIP2        = IF_FEATURE_SEAMLESS_BZ2( (1 << OPTBIT_BZIP2       )) + 0, // j
 818         OPT_LZMA         = IF_FEATURE_SEAMLESS_LZMA((1 << OPTBIT_LZMA        )) + 0, // a
 819         OPT_INCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_INCLUDE_FROM)) + 0, // T
 820         OPT_EXCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_EXCLUDE_FROM)) + 0, // X
 821         OPT_GZIP         = IF_FEATURE_SEAMLESS_GZ(  (1 << OPTBIT_GZIP        )) + 0, // z
 822         OPT_COMPRESS     = IF_FEATURE_SEAMLESS_Z(   (1 << OPTBIT_COMPRESS    )) + 0, // Z
 823         OPT_NOPRESERVE_TIME = IF_FEATURE_TAR_NOPRESERVE_TIME((1 << OPTBIT_NOPRESERVE_TIME)) + 0, // m
 824         OPT_2COMMAND        = IF_FEATURE_TAR_TO_COMMAND(  (1 << OPTBIT_2COMMAND       )) + 0, // to-command
 825         OPT_NUMERIC_OWNER   = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NUMERIC_OWNER  )) + 0, // numeric-owner
 826         OPT_NOPRESERVE_PERM = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOPRESERVE_PERM)) + 0, // no-same-permissions
 827         OPT_OVERWRITE       = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_OVERWRITE      )) + 0, // overwrite
 828 };
 829 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 830 static const char tar_longopts[] ALIGN1 =
 831         "list\0"                No_argument       "t"
 832         "extract\0"             No_argument       "x"
 833         "directory\0"           Required_argument "C"
 834         "file\0"                Required_argument "f"
 835         "to-stdout\0"           No_argument       "O"
 836         /* do not restore owner */
 837         /* Note: GNU tar handles 'o' as no-same-owner only on extract,
 838          * on create, 'o' is --old-archive. We do not support --old-archive. */
 839         "no-same-owner\0"       No_argument       "o"
 840         "same-permissions\0"    No_argument       "p"
 841         "verbose\0"             No_argument       "v"
 842         "keep-old\0"            No_argument       "k"
 843 # if ENABLE_FEATURE_TAR_CREATE
 844         "create\0"              No_argument       "c"
 845         "dereference\0"         No_argument       "h"
 846 # endif
 847 # if ENABLE_FEATURE_SEAMLESS_BZ2
 848         "bzip2\0"               No_argument       "j"
 849 # endif
 850 # if ENABLE_FEATURE_SEAMLESS_LZMA
 851         "lzma\0"                No_argument       "a"
 852 # endif
 853 # if ENABLE_FEATURE_TAR_FROM
 854         "files-from\0"          Required_argument "T"
 855         "exclude-from\0"        Required_argument "X"
 856 # endif
 857 # if ENABLE_FEATURE_SEAMLESS_GZ
 858         "gzip\0"                No_argument       "z"
 859 # endif
 860 # if ENABLE_FEATURE_SEAMLESS_Z
 861         "compress\0"            No_argument       "Z"
 862 # endif
 863 # if ENABLE_FEATURE_TAR_NOPRESERVE_TIME
 864         "touch\0"               No_argument       "m"
 865 # endif
 866 # if ENABLE_FEATURE_TAR_TO_COMMAND
 867         "to-command\0"          Required_argument "\xfb"
 868 # endif
 869         /* use numeric uid/gid from tar header, not textual */
 870         "numeric-owner\0"       No_argument       "\xfc"
 871         /* do not restore mode */
 872         "no-same-permissions\0" No_argument       "\xfd"
 873         /* on unpack, open with O_TRUNC and !O_EXCL */
 874         "overwrite\0"           No_argument       "\xfe"
 875         /* --exclude takes next bit position in option mask, */
 876         /* therefore we have to put it _after_ --no-same-permissions */
 877 # if ENABLE_FEATURE_TAR_FROM
 878         "exclude\0"             Required_argument "\xff"
 879 # endif
 880         ;
 881 #endif
 882
 883 int tar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 884 int tar_main(int argc UNUSED_PARAM, char **argv)
 885 {
 886         char FAST_FUNC (*get_header_ptr)(archive_handle_t *) = get_header_tar;
 887         archive_handle_t *tar_handle;
 888         char *base_dir = NULL;
 889         const char *tar_filename = "-";
 890         unsigned opt;
 891         int verboseFlag = 0;
 892 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 893         llist_t *excludes = NULL;
 894 #endif
 895
 896         /* Initialise default values */
 897         tar_handle = init_handle();
 898         tar_handle->ah_flags = ARCHIVE_CREATE_LEADING_DIRS
 899                              | ARCHIVE_RESTORE_DATE
 900                              | ARCHIVE_UNLINK_OLD;
 901
 902         /* Apparently only root's tar preserves perms (see bug 3844) */
 903         if (getuid() != 0)
 904                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
 905
 906         /* Prepend '-' to the first argument if required */
 907         opt_complementary = "--:" // first arg is options
 908                 "tt:vv:" // count -t,-v
 909                 "X::T::" // cumulative lists
 910 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 911                 "\xff::" // cumulative lists for --exclude
 912 #endif
 913                 IF_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
 914                 IF_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
 915                 IF_NOT_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
 916 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 917         applet_long_options = tar_longopts;
 918 #endif
 919 #if ENABLE_DESKTOP
 920         if (argv[1] && argv[1][0] != '-') {
 921                 /* Compat:
 922                  * 1st argument without dash handles options with parameters
 923                  * differently from dashed one: it takes *next argv[i]*
 924                  * as paramenter even if there are more chars in 1st argument:
 925                  *  "tar fx TARFILE" - "x" is not taken as f's param
 926                  *  but is interpreted as -x option
 927                  *  "tar -xf TARFILE" - dashed equivalent of the above
 928                  *  "tar -fx ..." - "x" is taken as f's param
 929                  * getopt32 wouldn't handle 1st command correctly.
 930                  * Unfortunately, people do use such commands.
 931                  * We massage argv[1] to work around it by moving 'f'
 932                  * to the end of the string.
 933                  * More contrived "tar fCx TARFILE DIR" still fails,
 934                  * but such commands are much less likely to be used.
 935                  */
 936                 char *f = strchr(argv[1], 'f');
 937                 if (f) {
 938                         while (f[1] != '\0') {
 939                                 *f = f[1];
 940                                 f++;
 941                         }
 942                         *f = 'f';
 943                 }
 944         }
 945 #endif
 946         opt = getopt32(argv,
 947                 "txC:f:Oopvk"
 948                 IF_FEATURE_TAR_CREATE(   "ch"  )
 949                 IF_FEATURE_SEAMLESS_BZ2( "j"   )
 950                 IF_FEATURE_SEAMLESS_LZMA("a"   )
 951                 IF_FEATURE_TAR_FROM(     "T:X:")
 952                 IF_FEATURE_SEAMLESS_GZ(  "z"   )
 953                 IF_FEATURE_SEAMLESS_Z(   "Z"   )
 954                 IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 955                 , &base_dir // -C dir
 956                 , &tar_filename // -f filename
 957                 IF_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
 958                 IF_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
 959                 IF_FEATURE_TAR_TO_COMMAND(, &(tar_handle->tar__to_command)) // --to-command
 960 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 961                 , &excludes // --exclude
 962 #endif
 963                 , &verboseFlag // combined count for -t and -v
 964                 , &verboseFlag // combined count for -t and -v
 965                 );
 966         //bb_error_msg("opt:%08x", opt);
 967         argv += optind;
 968
 969         if (verboseFlag) tar_handle->action_header = header_verbose_list;
 970         if (verboseFlag == 1) tar_handle->action_header = header_list;
 971
 972         if (opt & OPT_EXTRACT)
 973                 tar_handle->action_data = data_extract_all;
 974
 975         if (opt & OPT_2STDOUT)
 976                 tar_handle->action_data = data_extract_to_stdout;
 977
 978         if (opt & OPT_2COMMAND) {
 979                 putenv((char*)"TAR_FILETYPE=f");
 980                 signal(SIGPIPE, SIG_IGN);
 981                 tar_handle->action_data = data_extract_to_command;
 982         }
 983
 984         if (opt & OPT_KEEP_OLD)
 985                 tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
 986
 987         if (opt & OPT_NUMERIC_OWNER)
 988                 tar_handle->ah_flags |= ARCHIVE_NUMERIC_OWNER;
 989
 990         if (opt & OPT_NOPRESERVE_OWNER)
 991                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_OWNER;
 992
 993         if (opt & OPT_NOPRESERVE_PERM)
 994                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
 995
 996         if (opt & OPT_OVERWRITE) {
 997                 tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
 998                 tar_handle->ah_flags |= ARCHIVE_O_TRUNC;
 999         }
1000
1001         if (opt & OPT_GZIP)
1002                 get_header_ptr = get_header_tar_gz;
1003
1004         if (opt & OPT_BZIP2)
1005                 get_header_ptr = get_header_tar_bz2;
1006
1007         if (opt & OPT_LZMA)
1008                 get_header_ptr = get_header_tar_lzma;
1009
1010         if (opt & OPT_COMPRESS)
1011                 get_header_ptr = get_header_tar_Z;
1012
1013         if (opt & OPT_NOPRESERVE_TIME)
1014                 tar_handle->ah_flags &= ~ARCHIVE_RESTORE_DATE;
1015
1016 #if ENABLE_FEATURE_TAR_FROM
1017         tar_handle->reject = append_file_list_to_list(tar_handle->reject);
1018 # if ENABLE_FEATURE_TAR_LONG_OPTIONS
1019         /* Append excludes to reject */
1020         while (excludes) {
1021                 llist_t *next = excludes->link;
1022                 excludes->link = tar_handle->reject;
1023                 tar_handle->reject = excludes;
1024                 excludes = next;
1025         }
1026 # endif
1027         tar_handle->accept = append_file_list_to_list(tar_handle->accept);
1028 #endif
1029
1030         /* Setup an array of filenames to work with */
1031         /* TODO: This is the same as in ar, make a separate function? */
1032         while (*argv) {
1033                 /* kill trailing '/' unless the string is just "/" */
1034                 char *cp = last_char_is(*argv, '/');
1035                 if (cp > *argv)
1036                         *cp = '\0';
1037                 llist_add_to_end(&tar_handle->accept, *argv);
1038                 argv++;
1039         }
1040
1041         if (tar_handle->accept || tar_handle->reject)
1042                 tar_handle->filter = filter_accept_reject_list;
1043
1044         /* Open the tar file */
1045         {
1046                 int tar_fd = STDIN_FILENO;
1047                 int flags = O_RDONLY;
1048
1049                 if (opt & OPT_CREATE) {
1050                         /* Make sure there is at least one file to tar up */
1051                         if (tar_handle->accept == NULL)
1052                                 bb_error_msg_and_die("empty archive");
1053
1054                         tar_fd = STDOUT_FILENO;
1055                         /* Mimicking GNU tar 1.15.1: */
1056                         flags = O_WRONLY | O_CREAT | O_TRUNC;
1057                 }
1058
1059                 if (LONE_DASH(tar_filename)) {
1060                         tar_handle->src_fd = tar_fd;
1061                         tar_handle->seek = seek_by_read;
1062                 } else {
1063                         if (ENABLE_FEATURE_TAR_AUTODETECT && flags == O_RDONLY) {
1064                                 get_header_ptr = get_header_tar;
1065                                 tar_handle->src_fd = open_zipped(tar_filename);
1066                                 if (tar_handle->src_fd < 0)
1067                                         bb_perror_msg_and_die("can't open '%s'", tar_filename);
1068                         } else {
1069                                 tar_handle->src_fd = xopen(tar_filename, flags);
1070                         }
1071                 }
1072         }
1073
1074         if (base_dir)
1075                 xchdir(base_dir);
1076
1077 #ifdef CHECK_FOR_CHILD_EXITCODE
1078         /* We need to know whether child (gzip/bzip/etc) exits abnormally */
1079         signal(SIGCHLD, handle_SIGCHLD);
1080 #endif
1081
1082         /* Create an archive */
1083         if (opt & OPT_CREATE) {
1084 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
1085                 int zipMode = 0;
1086                 if (ENABLE_FEATURE_SEAMLESS_GZ && (opt & OPT_GZIP))
1087                         zipMode = 1;
1088                 if (ENABLE_FEATURE_SEAMLESS_BZ2 && (opt & OPT_BZIP2))
1089                         zipMode = 2;
1090 #endif
1091                 /* NB: writeTarFile() closes tar_handle->src_fd */
1092                 return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
1093                                 tar_handle->accept,
1094                                 tar_handle->reject, zipMode);
1095         }
1096
1097         while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
1098                 continue;
1099
1100         /* Check that every file that should have been extracted was */
1101         while (tar_handle->accept) {
1102                 if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
1103                  && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
1104                 ) {
1105                         bb_error_msg_and_die("%s: not found in archive",
1106                                 tar_handle->accept->data);
1107                 }
1108                 tar_handle->accept = tar_handle->accept->link;
1109         }
1110         if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
1111                 close(tar_handle->src_fd);
1112
1113         return EXIT_SUCCESS;
1114 }