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 "bb_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         /* users report that files with negative st_mtime cause trouble, so: */
 268         PUT_OCTAL(header.mtime, statbuf->st_mtime >= 0 ? statbuf->st_mtime : 0);
 269
 270         /* Enter the user and group names */
 271         safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
 272         safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
 273
 274         if (tbInfo->hlInfo) {
 275                 /* This is a hard link */
 276                 header.typeflag = LNKTYPE;
 277                 strncpy(header.linkname, tbInfo->hlInfo->name,
 278                                 sizeof(header.linkname));
 279 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 280                 /* Write out long linkname if needed */
 281                 if (header.linkname[sizeof(header.linkname)-1])
 282                         writeLongname(tbInfo->tarFd, GNULONGLINK,
 283                                         tbInfo->hlInfo->name, 0);
 284 #endif
 285         } else if (S_ISLNK(statbuf->st_mode)) {
 286                 char *lpath = xmalloc_readlink_or_warn(fileName);
 287                 if (!lpath)
 288                         return FALSE;
 289                 header.typeflag = SYMTYPE;
 290                 strncpy(header.linkname, lpath, sizeof(header.linkname));
 291 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 292                 /* Write out long linkname if needed */
 293                 if (header.linkname[sizeof(header.linkname)-1])
 294                         writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
 295 #else
 296                 /* If it is larger than 100 bytes, bail out */
 297                 if (header.linkname[sizeof(header.linkname)-1]) {
 298                         free(lpath);
 299                         bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 300                         return FALSE;
 301                 }
 302 #endif
 303                 free(lpath);
 304         } else if (S_ISDIR(statbuf->st_mode)) {
 305                 header.typeflag = DIRTYPE;
 306                 /* Append '/' only if there is a space for it */
 307                 if (!header.name[sizeof(header.name)-1])
 308                         header.name[strlen(header.name)] = '/';
 309         } else if (S_ISCHR(statbuf->st_mode)) {
 310                 header.typeflag = CHRTYPE;
 311                 PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
 312                 PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 313         } else if (S_ISBLK(statbuf->st_mode)) {
 314                 header.typeflag = BLKTYPE;
 315                 PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
 316                 PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 317         } else if (S_ISFIFO(statbuf->st_mode)) {
 318                 header.typeflag = FIFOTYPE;
 319         } else if (S_ISREG(statbuf->st_mode)) {
 320                 /* header.size field is 12 bytes long */
 321                 /* Does octal-encoded size fit? */
 322                 uoff_t filesize = statbuf->st_size;
 323                 if (sizeof(filesize) <= 4
 324                  || filesize <= (uoff_t)0777777777777LL
 325                 ) {
 326                         PUT_OCTAL(header.size, filesize);
 327                 }
 328                 /* Does base256-encoded size fit?
 329                  * It always does unless off_t is wider than 64 bits.
 330                  */
 331                 else if (ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 332 #if ULLONG_MAX > 0xffffffffffffffffLL /* 2^64-1 */
 333                  && (filesize <= 0x3fffffffffffffffffffffffLL)
 334 #endif
 335                 ) {
 336                         /* GNU tar uses "base-256 encoding" for very large numbers.
 337                          * Encoding is binary, with highest bit always set as a marker
 338                          * and sign in next-highest bit:
 339                          * 80 00 .. 00 - zero
 340                          * bf ff .. ff - largest positive number
 341                          * ff ff .. ff - minus 1
 342                          * c0 00 .. 00 - smallest negative number
 343                          */
 344                         char *p8 = header.size + sizeof(header.size);
 345                         do {
 346                                 *--p8 = (uint8_t)filesize;
 347                                 filesize >>= 8;
 348                         } while (p8 != header.size);
 349                         *p8 |= 0x80;
 350                 } else {
 351                         bb_error_msg_and_die("can't store file '%s' "
 352                                 "of size %"OFF_FMT"u, aborting",
 353                                 fileName, statbuf->st_size);
 354                 }
 355                 header.typeflag = REGTYPE;
 356         } else {
 357                 bb_error_msg("%s: unknown file type", fileName);
 358                 return FALSE;
 359         }
 360
 361 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 362         /* Write out long name if needed */
 363         /* (we, like GNU tar, output long linkname *before* long name) */
 364         if (header.name[sizeof(header.name)-1])
 365                 writeLongname(tbInfo->tarFd, GNULONGNAME,
 366                                 header_name, S_ISDIR(statbuf->st_mode));
 367 #endif
 368
 369         /* Now write the header out to disk */
 370         chksum_and_xwrite(tbInfo->tarFd, &header);
 371
 372         /* Now do the verbose thing (or not) */
 373         if (tbInfo->verboseFlag) {
 374                 FILE *vbFd = stdout;
 375
 376                 /* If archive goes to stdout, verbose goes to stderr */
 377                 if (tbInfo->tarFd == STDOUT_FILENO)
 378                         vbFd = stderr;
 379                 /* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
 380                 /* We don't have such excesses here: for us "v" == "vv" */
 381                 /* '/' is probably a GNUism */
 382                 fprintf(vbFd, "%s%s\n", header_name,
 383                                 S_ISDIR(statbuf->st_mode) ? "/" : "");
 384         }
 385
 386         return TRUE;
 387 }
 388
 389 #if ENABLE_FEATURE_TAR_FROM
 390 static int exclude_file(const llist_t *excluded_files, const char *file)
 391 {
 392         while (excluded_files) {
 393                 if (excluded_files->data[0] == '/') {
 394                         if (fnmatch(excluded_files->data, file,
 395                                         FNM_PATHNAME | FNM_LEADING_DIR) == 0)
 396                                 return 1;
 397                 } else {
 398                         const char *p;
 399
 400                         for (p = file; p[0] != '\0'; p++) {
 401                                 if ((p == file || p[-1] == '/')
 402                                  && p[0] != '/'
 403                                  && fnmatch(excluded_files->data, p,
 404                                                 FNM_PATHNAME | FNM_LEADING_DIR) == 0
 405                                 ) {
 406                                         return 1;
 407                                 }
 408                         }
 409                 }
 410                 excluded_files = excluded_files->link;
 411         }
 412
 413         return 0;
 414 }
 415 #else
 416 # define exclude_file(excluded_files, file) 0
 417 #endif
 418
 419 static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statbuf,
 420                         void *userData, int depth UNUSED_PARAM)
 421 {
 422         struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
 423         const char *header_name;
 424         int inputFileFd = -1;
 425
 426         DBG("writeFileToTarball('%s')", fileName);
 427
 428         /* Strip leading '/' and such (must be before memorizing hardlink's name) */
 429         header_name = strip_unsafe_prefix(fileName);
 430
 431         if (header_name[0] == '\0')
 432                 return TRUE;
 433
 434         /* It is against the rules to archive a socket */
 435         if (S_ISSOCK(statbuf->st_mode)) {
 436                 bb_error_msg("%s: socket ignored", fileName);
 437                 return TRUE;
 438         }
 439
 440         /*
 441          * Check to see if we are dealing with a hard link.
 442          * If so -
 443          * Treat the first occurance of a given dev/inode as a file while
 444          * treating any additional occurances as hard links.  This is done
 445          * by adding the file information to the HardLinkInfo linked list.
 446          */
 447         tbInfo->hlInfo = NULL;
 448         if (!S_ISDIR(statbuf->st_mode) && statbuf->st_nlink > 1) {
 449                 DBG("'%s': st_nlink > 1", header_name);
 450                 tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
 451                 if (tbInfo->hlInfo == NULL) {
 452                         DBG("'%s': addHardLinkInfo", header_name);
 453                         addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, header_name);
 454                 }
 455         }
 456
 457         /* It is a bad idea to store the archive we are in the process of creating,
 458          * so check the device and inode to be sure that this particular file isn't
 459          * the new tarball */
 460         if (tbInfo->tarFileStatBuf.st_dev == statbuf->st_dev
 461          && tbInfo->tarFileStatBuf.st_ino == statbuf->st_ino
 462         ) {
 463                 bb_error_msg("%s: file is the archive; skipping", fileName);
 464                 return TRUE;
 465         }
 466
 467         if (exclude_file(tbInfo->excludeList, header_name))
 468                 return SKIP;
 469
 470 #if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 471         if (strlen(header_name) >= NAME_SIZE) {
 472                 bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 473                 return TRUE;
 474         }
 475 #endif
 476
 477         /* Is this a regular file? */
 478         if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
 479                 /* open the file we want to archive, and make sure all is well */
 480                 inputFileFd = open_or_warn(fileName, O_RDONLY);
 481                 if (inputFileFd < 0) {
 482                         return FALSE;
 483                 }
 484         }
 485
 486         /* Add an entry to the tarball */
 487         if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
 488                 return FALSE;
 489         }
 490
 491         /* If it was a regular file, write out the body */
 492         if (inputFileFd >= 0) {
 493                 size_t readSize;
 494                 /* Write the file to the archive. */
 495                 /* We record size into header first, */
 496                 /* and then write out file. If file shrinks in between, */
 497                 /* tar will be corrupted. So we don't allow for that. */
 498                 /* NB: GNU tar 1.16 warns and pads with zeroes */
 499                 /* or even seeks back and updates header */
 500                 bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
 501                 ////off_t readSize;
 502                 ////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
 503                 ////if (readSize != statbuf->st_size && readSize >= 0) {
 504                 ////    bb_error_msg_and_die("short read from %s, aborting", fileName);
 505                 ////}
 506
 507                 /* Check that file did not grow in between? */
 508                 /* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
 509
 510                 close(inputFileFd);
 511
 512                 /* Pad the file up to the tar block size */
 513                 /* (a few tricks here in the name of code size) */
 514                 readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
 515                 memset(block_buf, 0, readSize);
 516                 xwrite(tbInfo->tarFd, block_buf, readSize);
 517         }
 518
 519         return TRUE;
 520 }
 521
 522 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 523 # if !(ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2)
 524 #  define vfork_compressor(tar_fd, gzip) vfork_compressor(tar_fd)
 525 # endif
 526 /* Don't inline: vfork scares gcc and pessimizes code */
 527 static void NOINLINE vfork_compressor(int tar_fd, int gzip)
 528 {
 529         pid_t gzipPid;
 530 # if ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2
 531         const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
 532 # elif ENABLE_FEATURE_SEAMLESS_GZ
 533         const char *zip_exec = "gzip";
 534 # else /* only ENABLE_FEATURE_SEAMLESS_BZ2 */
 535         const char *zip_exec = "bzip2";
 536 # endif
 537         // On Linux, vfork never unpauses parent early, although standard
 538         // allows for that. Do we want to waste bytes checking for it?
 539 # define WAIT_FOR_CHILD 0
 540         volatile int vfork_exec_errno = 0;
 541         struct fd_pair gzipDataPipe;
 542 # if WAIT_FOR_CHILD
 543         struct fd_pair gzipStatusPipe;
 544         xpiped_pair(gzipStatusPipe);
 545 # endif
 546         xpiped_pair(gzipDataPipe);
 547
 548         signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
 549
 550 # if defined(__GNUC__) && __GNUC__
 551         /* Avoid vfork clobbering */
 552         (void) &zip_exec;
 553 # endif
 554
 555         gzipPid = xvfork();
 556
 557         if (gzipPid == 0) {
 558                 /* child */
 559                 /* NB: close _first_, then move fds! */
 560                 close(gzipDataPipe.wr);
 561 # if WAIT_FOR_CHILD
 562                 close(gzipStatusPipe.rd);
 563                 /* gzipStatusPipe.wr will close only on exec -
 564                  * parent waits for this close to happen */
 565                 fcntl(gzipStatusPipe.wr, F_SETFD, FD_CLOEXEC);
 566 # endif
 567                 xmove_fd(gzipDataPipe.rd, 0);
 568                 xmove_fd(tar_fd, 1);
 569                 /* exec gzip/bzip2 program/applet */
 570                 BB_EXECLP(zip_exec, zip_exec, "-f", NULL);
 571                 vfork_exec_errno = errno;
 572                 _exit(EXIT_FAILURE);
 573         }
 574
 575         /* parent */
 576         xmove_fd(gzipDataPipe.wr, tar_fd);
 577         close(gzipDataPipe.rd);
 578 # if WAIT_FOR_CHILD
 579         close(gzipStatusPipe.wr);
 580         while (1) {
 581                 char buf;
 582                 int n;
 583
 584                 /* Wait until child execs (or fails to) */
 585                 n = full_read(gzipStatusPipe.rd, &buf, 1);
 586                 if (n < 0 /* && errno == EAGAIN */)
 587                         continue;       /* try it again */
 588         }
 589         close(gzipStatusPipe.rd);
 590 # endif
 591         if (vfork_exec_errno) {
 592                 errno = vfork_exec_errno;
 593                 bb_perror_msg_and_die("can't execute '%s'", zip_exec);
 594         }
 595 }
 596 #endif /* ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2 */
 597
 598
 599 /* gcc 4.2.1 inlines it, making code bigger */
 600 static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
 601         int dereferenceFlag, const llist_t *include,
 602         const llist_t *exclude, int gzip)
 603 {
 604         int errorFlag = FALSE;
 605         struct TarBallInfo tbInfo;
 606
 607         tbInfo.hlInfoHead = NULL;
 608         tbInfo.tarFd = tar_fd;
 609         tbInfo.verboseFlag = verboseFlag;
 610
 611         /* Store the stat info for the tarball's file, so
 612          * can avoid including the tarball into itself....  */
 613         xfstat(tbInfo.tarFd, &tbInfo.tarFileStatBuf, "can't stat tar file");
 614
 615 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 616         if (gzip)
 617                 vfork_compressor(tbInfo.tarFd, gzip);
 618 #endif
 619
 620         tbInfo.excludeList = exclude;
 621
 622         /* Read the directory/files and iterate over them one at a time */
 623         while (include) {
 624                 if (!recursive_action(include->data, ACTION_RECURSE |
 625                                 (dereferenceFlag ? ACTION_FOLLOWLINKS : 0),
 626                                 writeFileToTarball, writeFileToTarball, &tbInfo, 0)
 627                 ) {
 628                         errorFlag = TRUE;
 629                 }
 630                 include = include->link;
 631         }
 632         /* Write two empty blocks to the end of the archive */
 633         memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
 634         xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
 635
 636         /* To be pedantically correct, we would check if the tarball
 637          * is smaller than 20 tar blocks, and pad it if it was smaller,
 638          * but that isn't necessary for GNU tar interoperability, and
 639          * so is considered a waste of space */
 640
 641         /* Close so the child process (if any) will exit */
 642         close(tbInfo.tarFd);
 643
 644         /* Hang up the tools, close up shop, head home */
 645         if (ENABLE_FEATURE_CLEAN_UP)
 646                 freeHardLinkInfo(&tbInfo.hlInfoHead);
 647
 648         if (errorFlag)
 649                 bb_error_msg("error exit delayed from previous errors");
 650
 651 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 652         if (gzip) {
 653                 int status;
 654                 if (safe_waitpid(-1, &status, 0) == -1)
 655                         bb_perror_msg("waitpid");
 656                 else if (!WIFEXITED(status) || WEXITSTATUS(status))
 657                         /* gzip was killed or has exited with nonzero! */
 658                         errorFlag = TRUE;
 659         }
 660 #endif
 661         return errorFlag;
 662 }
 663 #else
 664 int writeTarFile(int tar_fd, int verboseFlag,
 665         int dereferenceFlag, const llist_t *include,
 666         const llist_t *exclude, int gzip);
 667 #endif /* FEATURE_TAR_CREATE */
 668
 669 #if ENABLE_FEATURE_TAR_FROM
 670 static llist_t *append_file_list_to_list(llist_t *list)
 671 {
 672         FILE *src_stream;
 673         char *line;
 674         llist_t *newlist = NULL;
 675
 676         while (list) {
 677                 src_stream = xfopen_stdin(llist_pop(&list));
 678                 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
 679                         /* kill trailing '/' unless the string is just "/" */
 680                         char *cp = last_char_is(line, '/');
 681                         if (cp > line)
 682                                 *cp = '\0';
 683                         llist_add_to(&newlist, line);
 684                 }
 685                 fclose(src_stream);
 686         }
 687         return newlist;
 688 }
 689 #else
 690 # define append_file_list_to_list(x) 0
 691 #endif
 692
 693 #if ENABLE_FEATURE_SEAMLESS_Z
 694 static char FAST_FUNC get_header_tar_Z(archive_handle_t *archive_handle)
 695 {
 696         /* Can't lseek over pipes */
 697         archive_handle->seek = seek_by_read;
 698
 699         /* do the decompression, and cleanup */
 700         if (xread_char(archive_handle->src_fd) != 0x1f
 701          || xread_char(archive_handle->src_fd) != 0x9d
 702         ) {
 703                 bb_error_msg_and_die("invalid magic");
 704         }
 705
 706         open_transformer(archive_handle->src_fd, unpack_Z_stream, "uncompress");
 707         archive_handle->offset = 0;
 708         while (get_header_tar(archive_handle) == EXIT_SUCCESS)
 709                 continue;
 710
 711         /* Can only do one file at a time */
 712         return EXIT_FAILURE;
 713 }
 714 #else
 715 # define get_header_tar_Z NULL
 716 #endif
 717
 718 #ifdef CHECK_FOR_CHILD_EXITCODE
 719 /* Looks like it isn't needed - tar detects malformed (truncated)
 720  * archive if e.g. bunzip2 fails */
 721 static int child_error;
 722
 723 static void handle_SIGCHLD(int status)
 724 {
 725         /* Actually, 'status' is a signo. We reuse it for other needs */
 726
 727         /* Wait for any child without blocking */
 728         if (wait_any_nohang(&status) < 0)
 729                 /* wait failed?! I'm confused... */
 730                 return;
 731
 732         if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
 733                 /* child exited with 0 */
 734                 return;
 735         /* Cannot happen?
 736         if (!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
 737         child_error = 1;
 738 }
 739 #endif
 740
 741 //usage:#define tar_trivial_usage
 742 //usage:        "-[" IF_FEATURE_TAR_CREATE("c") "xt"
 743 //usage:        IF_FEATURE_SEAMLESS_Z("Z")
 744 //usage:        IF_FEATURE_SEAMLESS_GZ("z")
 745 //usage:        IF_FEATURE_SEAMLESS_BZ2("j")
 746 //usage:        IF_FEATURE_SEAMLESS_LZMA("a")
 747 //usage:        IF_FEATURE_TAR_CREATE("h")
 748 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 749 //usage:        "vO] "
 750 //usage:        IF_FEATURE_TAR_FROM("[-X FILE] [-T FILE] ")
 751 //usage:        "[-f TARFILE] [-C DIR] [FILE]..."
 752 //usage:#define tar_full_usage "\n\n"
 753 //usage:        IF_FEATURE_TAR_CREATE("Create, extract, ")
 754 //usage:        IF_NOT_FEATURE_TAR_CREATE("Extract ")
 755 //usage:        "or list files from a tar file\n"
 756 //usage:     "\nOperation:"
 757 //usage:        IF_FEATURE_TAR_CREATE(
 758 //usage:     "\n        c       Create"
 759 //usage:        )
 760 //usage:     "\n        x       Extract"
 761 //usage:     "\n        t       List"
 762 //usage:     "\n        f       Name of TARFILE ('-' for stdin/out)"
 763 //usage:     "\n        C       Change to DIR before operation"
 764 //usage:     "\n        v       Verbose"
 765 //usage:        IF_FEATURE_SEAMLESS_Z(
 766 //usage:     "\n        Z       (De)compress using compress"
 767 //usage:        )
 768 //usage:        IF_FEATURE_SEAMLESS_GZ(
 769 //usage:     "\n        z       (De)compress using gzip"
 770 //usage:        )
 771 //usage:        IF_FEATURE_SEAMLESS_BZ2(
 772 //usage:     "\n        j       (De)compress using bzip2"
 773 //usage:        )
 774 //usage:        IF_FEATURE_SEAMLESS_LZMA(
 775 //usage:     "\n        a       (De)compress using lzma"
 776 //usage:        )
 777 //usage:     "\n        O       Extract to stdout"
 778 //usage:        IF_FEATURE_TAR_CREATE(
 779 //usage:     "\n        h       Follow symlinks"
 780 //usage:        )
 781 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME(
 782 //usage:     "\n        m       Don't restore mtime"
 783 //usage:        )
 784 //usage:        IF_FEATURE_TAR_FROM(
 785 //usage:        IF_FEATURE_TAR_LONG_OPTIONS(
 786 //usage:     "\n        exclude File to exclude"
 787 //usage:        )
 788 //usage:     "\n        X       File with names to exclude"
 789 //usage:     "\n        T       File with names to include"
 790 //usage:        )
 791 //usage:
 792 //usage:#define tar_example_usage
 793 //usage:       "$ zcat /tmp/tarball.tar.gz | tar -xf -\n"
 794 //usage:       "$ tar -cf /tmp/tarball.tar /usr/local\n"
 795
 796 // Supported but aren't in --help:
 797 //      o       no-same-owner
 798 //      p       same-permissions
 799 //      k       keep-old
 800 //      numeric-owner
 801 //      no-same-permissions
 802 //      overwrite
 803 //IF_FEATURE_TAR_TO_COMMAND(
 804 //      to-command
 805 //)
 806
 807 enum {
 808         OPTBIT_KEEP_OLD = 8,
 809         IF_FEATURE_TAR_CREATE(   OPTBIT_CREATE      ,)
 810         IF_FEATURE_TAR_CREATE(   OPTBIT_DEREFERENCE ,)
 811         IF_FEATURE_SEAMLESS_BZ2( OPTBIT_BZIP2       ,)
 812         IF_FEATURE_SEAMLESS_LZMA(OPTBIT_LZMA        ,)
 813         IF_FEATURE_TAR_FROM(     OPTBIT_INCLUDE_FROM,)
 814         IF_FEATURE_TAR_FROM(     OPTBIT_EXCLUDE_FROM,)
 815         IF_FEATURE_SEAMLESS_GZ(  OPTBIT_GZIP        ,)
 816         IF_FEATURE_SEAMLESS_Z(   OPTBIT_COMPRESS    ,) // 16th bit
 817         IF_FEATURE_TAR_NOPRESERVE_TIME(OPTBIT_NOPRESERVE_TIME,)
 818 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 819         IF_FEATURE_TAR_TO_COMMAND(OPTBIT_2COMMAND   ,)
 820         OPTBIT_NUMERIC_OWNER,
 821         OPTBIT_NOPRESERVE_PERM,
 822         OPTBIT_OVERWRITE,
 823 #endif
 824         OPT_TEST         = 1 << 0, // t
 825         OPT_EXTRACT      = 1 << 1, // x
 826         OPT_BASEDIR      = 1 << 2, // C
 827         OPT_TARNAME      = 1 << 3, // f
 828         OPT_2STDOUT      = 1 << 4, // O
 829         OPT_NOPRESERVE_OWNER = 1 << 5, // o == no-same-owner
 830         OPT_P            = 1 << 6, // p
 831         OPT_VERBOSE      = 1 << 7, // v
 832         OPT_KEEP_OLD     = 1 << 8, // k
 833         OPT_CREATE       = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_CREATE      )) + 0, // c
 834         OPT_DEREFERENCE  = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_DEREFERENCE )) + 0, // h
 835         OPT_BZIP2        = IF_FEATURE_SEAMLESS_BZ2( (1 << OPTBIT_BZIP2       )) + 0, // j
 836         OPT_LZMA         = IF_FEATURE_SEAMLESS_LZMA((1 << OPTBIT_LZMA        )) + 0, // a
 837         OPT_INCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_INCLUDE_FROM)) + 0, // T
 838         OPT_EXCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_EXCLUDE_FROM)) + 0, // X
 839         OPT_GZIP         = IF_FEATURE_SEAMLESS_GZ(  (1 << OPTBIT_GZIP        )) + 0, // z
 840         OPT_COMPRESS     = IF_FEATURE_SEAMLESS_Z(   (1 << OPTBIT_COMPRESS    )) + 0, // Z
 841         OPT_NOPRESERVE_TIME = IF_FEATURE_TAR_NOPRESERVE_TIME((1 << OPTBIT_NOPRESERVE_TIME)) + 0, // m
 842         OPT_2COMMAND        = IF_FEATURE_TAR_TO_COMMAND(  (1 << OPTBIT_2COMMAND       )) + 0, // to-command
 843         OPT_NUMERIC_OWNER   = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NUMERIC_OWNER  )) + 0, // numeric-owner
 844         OPT_NOPRESERVE_PERM = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOPRESERVE_PERM)) + 0, // no-same-permissions
 845         OPT_OVERWRITE       = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_OVERWRITE      )) + 0, // overwrite
 846 };
 847 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 848 static const char tar_longopts[] ALIGN1 =
 849         "list\0"                No_argument       "t"
 850         "extract\0"             No_argument       "x"
 851         "directory\0"           Required_argument "C"
 852         "file\0"                Required_argument "f"
 853         "to-stdout\0"           No_argument       "O"
 854         /* do not restore owner */
 855         /* Note: GNU tar handles 'o' as no-same-owner only on extract,
 856          * on create, 'o' is --old-archive. We do not support --old-archive. */
 857         "no-same-owner\0"       No_argument       "o"
 858         "same-permissions\0"    No_argument       "p"
 859         "verbose\0"             No_argument       "v"
 860         "keep-old\0"            No_argument       "k"
 861 # if ENABLE_FEATURE_TAR_CREATE
 862         "create\0"              No_argument       "c"
 863         "dereference\0"         No_argument       "h"
 864 # endif
 865 # if ENABLE_FEATURE_SEAMLESS_BZ2
 866         "bzip2\0"               No_argument       "j"
 867 # endif
 868 # if ENABLE_FEATURE_SEAMLESS_LZMA
 869         "lzma\0"                No_argument       "a"
 870 # endif
 871 # if ENABLE_FEATURE_TAR_FROM
 872         "files-from\0"          Required_argument "T"
 873         "exclude-from\0"        Required_argument "X"
 874 # endif
 875 # if ENABLE_FEATURE_SEAMLESS_GZ
 876         "gzip\0"                No_argument       "z"
 877 # endif
 878 # if ENABLE_FEATURE_SEAMLESS_Z
 879         "compress\0"            No_argument       "Z"
 880 # endif
 881 # if ENABLE_FEATURE_TAR_NOPRESERVE_TIME
 882         "touch\0"               No_argument       "m"
 883 # endif
 884 # if ENABLE_FEATURE_TAR_TO_COMMAND
 885         "to-command\0"          Required_argument "\xfb"
 886 # endif
 887         /* use numeric uid/gid from tar header, not textual */
 888         "numeric-owner\0"       No_argument       "\xfc"
 889         /* do not restore mode */
 890         "no-same-permissions\0" No_argument       "\xfd"
 891         /* on unpack, open with O_TRUNC and !O_EXCL */
 892         "overwrite\0"           No_argument       "\xfe"
 893         /* --exclude takes next bit position in option mask, */
 894         /* therefore we have to put it _after_ --no-same-permissions */
 895 # if ENABLE_FEATURE_TAR_FROM
 896         "exclude\0"             Required_argument "\xff"
 897 # endif
 898         ;
 899 #endif
 900
 901 int tar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 902 int tar_main(int argc UNUSED_PARAM, char **argv)
 903 {
 904         char FAST_FUNC (*get_header_ptr)(archive_handle_t *) = get_header_tar;
 905         archive_handle_t *tar_handle;
 906         char *base_dir = NULL;
 907         const char *tar_filename = "-";
 908         unsigned opt;
 909         int verboseFlag = 0;
 910 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 911         llist_t *excludes = NULL;
 912 #endif
 913
 914         /* Initialise default values */
 915         tar_handle = init_handle();
 916         tar_handle->ah_flags = ARCHIVE_CREATE_LEADING_DIRS
 917                              | ARCHIVE_RESTORE_DATE
 918                              | ARCHIVE_UNLINK_OLD;
 919
 920         /* Apparently only root's tar preserves perms (see bug 3844) */
 921         if (getuid() != 0)
 922                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
 923
 924         /* Prepend '-' to the first argument if required */
 925         opt_complementary = "--:" // first arg is options
 926                 "tt:vv:" // count -t,-v
 927                 IF_FEATURE_TAR_FROM("X::T::") // cumulative lists
 928 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 929                 "\xff::" // cumulative lists for --exclude
 930 #endif
 931                 IF_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
 932                 IF_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
 933                 IF_NOT_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
 934 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 935         applet_long_options = tar_longopts;
 936 #endif
 937 #if ENABLE_DESKTOP
 938         if (argv[1] && argv[1][0] != '-') {
 939                 /* Compat:
 940                  * 1st argument without dash handles options with parameters
 941                  * differently from dashed one: it takes *next argv[i]*
 942                  * as paramenter even if there are more chars in 1st argument:
 943                  *  "tar fx TARFILE" - "x" is not taken as f's param
 944                  *  but is interpreted as -x option
 945                  *  "tar -xf TARFILE" - dashed equivalent of the above
 946                  *  "tar -fx ..." - "x" is taken as f's param
 947                  * getopt32 wouldn't handle 1st command correctly.
 948                  * Unfortunately, people do use such commands.
 949                  * We massage argv[1] to work around it by moving 'f'
 950                  * to the end of the string.
 951                  * More contrived "tar fCx TARFILE DIR" still fails,
 952                  * but such commands are much less likely to be used.
 953                  */
 954                 char *f = strchr(argv[1], 'f');
 955                 if (f) {
 956                         while (f[1] != '\0') {
 957                                 *f = f[1];
 958                                 f++;
 959                         }
 960                         *f = 'f';
 961                 }
 962         }
 963 #endif
 964         opt = getopt32(argv,
 965                 "txC:f:Oopvk"
 966                 IF_FEATURE_TAR_CREATE(   "ch"  )
 967                 IF_FEATURE_SEAMLESS_BZ2( "j"   )
 968                 IF_FEATURE_SEAMLESS_LZMA("a"   )
 969                 IF_FEATURE_TAR_FROM(     "T:X:")
 970                 IF_FEATURE_SEAMLESS_GZ(  "z"   )
 971                 IF_FEATURE_SEAMLESS_Z(   "Z"   )
 972                 IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 973                 , &base_dir // -C dir
 974                 , &tar_filename // -f filename
 975                 IF_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
 976                 IF_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
 977                 IF_FEATURE_TAR_TO_COMMAND(, &(tar_handle->tar__to_command)) // --to-command
 978 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 979                 , &excludes // --exclude
 980 #endif
 981                 , &verboseFlag // combined count for -t and -v
 982                 , &verboseFlag // combined count for -t and -v
 983                 );
 984         //bb_error_msg("opt:%08x", opt);
 985         argv += optind;
 986
 987         if (verboseFlag) tar_handle->action_header = header_verbose_list;
 988         if (verboseFlag == 1) tar_handle->action_header = header_list;
 989
 990         if (opt & OPT_EXTRACT)
 991                 tar_handle->action_data = data_extract_all;
 992
 993         if (opt & OPT_2STDOUT)
 994                 tar_handle->action_data = data_extract_to_stdout;
 995
 996         if (opt & OPT_2COMMAND) {
 997                 putenv((char*)"TAR_FILETYPE=f");
 998                 signal(SIGPIPE, SIG_IGN);
 999                 tar_handle->action_data = data_extract_to_command;
1000                 IF_FEATURE_TAR_TO_COMMAND(tar_handle->tar__to_command_shell = xstrdup(get_shell_name());)
1001         }
1002
1003         if (opt & OPT_KEEP_OLD)
1004                 tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
1005
1006         if (opt & OPT_NUMERIC_OWNER)
1007                 tar_handle->ah_flags |= ARCHIVE_NUMERIC_OWNER;
1008
1009         if (opt & OPT_NOPRESERVE_OWNER)
1010                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_OWNER;
1011
1012         if (opt & OPT_NOPRESERVE_PERM)
1013                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
1014
1015         if (opt & OPT_OVERWRITE) {
1016                 tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
1017                 tar_handle->ah_flags |= ARCHIVE_O_TRUNC;
1018         }
1019
1020         if (opt & OPT_GZIP)
1021                 get_header_ptr = get_header_tar_gz;
1022
1023         if (opt & OPT_BZIP2)
1024                 get_header_ptr = get_header_tar_bz2;
1025
1026         if (opt & OPT_LZMA)
1027                 get_header_ptr = get_header_tar_lzma;
1028
1029         if (opt & OPT_COMPRESS)
1030                 get_header_ptr = get_header_tar_Z;
1031
1032         if (opt & OPT_NOPRESERVE_TIME)
1033                 tar_handle->ah_flags &= ~ARCHIVE_RESTORE_DATE;
1034
1035 #if ENABLE_FEATURE_TAR_FROM
1036         tar_handle->reject = append_file_list_to_list(tar_handle->reject);
1037 # if ENABLE_FEATURE_TAR_LONG_OPTIONS
1038         /* Append excludes to reject */
1039         while (excludes) {
1040                 llist_t *next = excludes->link;
1041                 excludes->link = tar_handle->reject;
1042                 tar_handle->reject = excludes;
1043                 excludes = next;
1044         }
1045 # endif
1046         tar_handle->accept = append_file_list_to_list(tar_handle->accept);
1047 #endif
1048
1049         /* Setup an array of filenames to work with */
1050         /* TODO: This is the same as in ar, make a separate function? */
1051         while (*argv) {
1052                 /* kill trailing '/' unless the string is just "/" */
1053                 char *cp = last_char_is(*argv, '/');
1054                 if (cp > *argv)
1055                         *cp = '\0';
1056                 llist_add_to_end(&tar_handle->accept, *argv);
1057                 argv++;
1058         }
1059
1060         if (tar_handle->accept || tar_handle->reject)
1061                 tar_handle->filter = filter_accept_reject_list;
1062
1063         /* Open the tar file */
1064         {
1065                 int tar_fd = STDIN_FILENO;
1066                 int flags = O_RDONLY;
1067
1068                 if (opt & OPT_CREATE) {
1069                         /* Make sure there is at least one file to tar up */
1070                         if (tar_handle->accept == NULL)
1071                                 bb_error_msg_and_die("empty archive");
1072
1073                         tar_fd = STDOUT_FILENO;
1074                         /* Mimicking GNU tar 1.15.1: */
1075                         flags = O_WRONLY | O_CREAT | O_TRUNC;
1076                 }
1077
1078                 if (LONE_DASH(tar_filename)) {
1079                         tar_handle->src_fd = tar_fd;
1080                         tar_handle->seek = seek_by_read;
1081                 } else {
1082                         if (ENABLE_FEATURE_TAR_AUTODETECT
1083                          && flags == O_RDONLY
1084                          && get_header_ptr == get_header_tar
1085                         ) {
1086                                 tar_handle->src_fd = open_zipped(tar_filename);
1087                                 if (tar_handle->src_fd < 0)
1088                                         bb_perror_msg_and_die("can't open '%s'", tar_filename);
1089                         } else {
1090                                 tar_handle->src_fd = xopen(tar_filename, flags);
1091                         }
1092                 }
1093         }
1094
1095         if (base_dir)
1096                 xchdir(base_dir);
1097
1098 #ifdef CHECK_FOR_CHILD_EXITCODE
1099         /* We need to know whether child (gzip/bzip/etc) exits abnormally */
1100         signal(SIGCHLD, handle_SIGCHLD);
1101 #endif
1102
1103         /* Create an archive */
1104         if (opt & OPT_CREATE) {
1105 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
1106                 int zipMode = 0;
1107                 if (ENABLE_FEATURE_SEAMLESS_GZ && (opt & OPT_GZIP))
1108                         zipMode = 1;
1109                 if (ENABLE_FEATURE_SEAMLESS_BZ2 && (opt & OPT_BZIP2))
1110                         zipMode = 2;
1111 #endif
1112                 /* NB: writeTarFile() closes tar_handle->src_fd */
1113                 return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
1114                                 tar_handle->accept,
1115                                 tar_handle->reject, zipMode);
1116         }
1117
1118         while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
1119                 continue;
1120
1121         /* Check that every file that should have been extracted was */
1122         while (tar_handle->accept) {
1123                 if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
1124                  && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
1125                 ) {
1126                         bb_error_msg_and_die("%s: not found in archive",
1127                                 tar_handle->accept->data);
1128                 }
1129                 tar_handle->accept = tar_handle->accept->link;
1130         }
1131         if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
1132                 close(tar_handle->src_fd);
1133
1134         return EXIT_SUCCESS;
1135 }