archival/tar.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini tar implementation for busybox
   4  *
   5  * Modified to use common extraction code used by ar, cpio, dpkg-deb, dpkg
   6  *  by Glenn McGrath
   7  *
   8  * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
   9  * ground up.  It still has remnants of the old code lying about, but it is
  10  * very different now (i.e., cleaner, less global variables, etc.)
  11  *
  12  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  13  *
  14  * Based in part in the tar implementation in sash
  15  *  Copyright (c) 1999 by David I. Bell
  16  *  Permission is granted to use, distribute, or modify this source,
  17  *  provided that this copyright notice remains intact.
  18  *  Permission to distribute sash derived code under GPL has been granted.
  19  *
  20  * Based in part on the tar implementation from busybox-0.28
  21  *  Copyright (C) 1995 Bruce Perens
  22  *
  23  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  24  */
  25 /* TODO: security with -C DESTDIR option can be enhanced.
  26  * Consider tar file created via:
  27  * $ tar cvf bug.tar anything.txt
  28  * $ ln -s /tmp symlink
  29  * $ tar --append -f bug.tar symlink
  30  * $ rm symlink
  31  * $ mkdir symlink
  32  * $ tar --append -f bug.tar symlink/evil.py
  33  *
  34  * This will result in an archive which contains:
  35  * $ tar --list -f bug.tar
  36  * anything.txt
  37  * symlink
  38  * symlink/evil.py
  39  *
  40  * Untarring it puts evil.py in '/tmp' even if the -C DESTDIR is given.
  41  * This doesn't feel right, and IIRC GNU tar doesn't do that.
  42  */
  43
  44 //config:config TAR
  45 //config:       bool "tar"
  46 //config:       default y
  47 //config:       help
  48 //config:         tar is an archiving program. It's commonly used with gzip to
  49 //config:         create compressed archives. It's probably the most widely used
  50 //config:         UNIX archive program.
  51 //config:
  52 //config:config FEATURE_TAR_CREATE
  53 //config:       bool "Enable archive creation"
  54 //config:       default y
  55 //config:       depends on TAR
  56 //config:       help
  57 //config:         If you enable this option you'll be able to create
  58 //config:         tar archives using the `-c' option.
  59 //config:
  60 //config:config FEATURE_TAR_AUTODETECT
  61 //config:       bool "Autodetect compressed tarballs"
  62 //config:       default y
  63 //config:       depends on TAR && (FEATURE_SEAMLESS_Z || FEATURE_SEAMLESS_GZ || FEATURE_SEAMLESS_BZ2 || FEATURE_SEAMLESS_LZMA || FEATURE_SEAMLESS_XZ)
  64 //config:       help
  65 //config:         With this option tar can automatically detect compressed
  66 //config:         tarballs. Currently it works only on files (not pipes etc).
  67 //config:
  68 //config:config FEATURE_TAR_FROM
  69 //config:       bool "Enable -X (exclude from) and -T (include from) options)"
  70 //config:       default y
  71 //config:       depends on TAR
  72 //config:       help
  73 //config:         If you enable this option you'll be able to specify
  74 //config:         a list of files to include or exclude from an archive.
  75 //config:
  76 //config:config FEATURE_TAR_OLDGNU_COMPATIBILITY
  77 //config:       bool "Support for old tar header format"
  78 //config:       default y
  79 //config:       depends on TAR || DPKG
  80 //config:       help
  81 //config:         This option is required to unpack archives created in
  82 //config:         the old GNU format; help to kill this old format by
  83 //config:         repacking your ancient archives with the new format.
  84 //config:
  85 //config:config FEATURE_TAR_OLDSUN_COMPATIBILITY
  86 //config:       bool "Enable untarring of tarballs with checksums produced by buggy Sun tar"
  87 //config:       default y
  88 //config:       depends on TAR || DPKG
  89 //config:       help
  90 //config:         This option is required to unpack archives created by some old
  91 //config:         version of Sun's tar (it was calculating checksum using signed
  92 //config:         arithmetic). It is said to be fixed in newer Sun tar, but "old"
  93 //config:         tarballs still exist.
  94 //config:
  95 //config:config FEATURE_TAR_GNU_EXTENSIONS
  96 //config:       bool "Support for GNU tar extensions (long filenames)"
  97 //config:       default y
  98 //config:       depends on TAR || DPKG
  99 //config:       help
 100 //config:         With this option busybox supports GNU long filenames and
 101 //config:         linknames.
 102 //config:
 103 //config:config FEATURE_TAR_LONG_OPTIONS
 104 //config:       bool "Enable long options"
 105 //config:       default y
 106 //config:       depends on TAR && LONG_OPTS
 107 //config:       help
 108 //config:         Enable use of long options, increases size by about 400 Bytes
 109 //config:
 110 //config:config FEATURE_TAR_TO_COMMAND
 111 //config:       bool "Support for writing to an external program"
 112 //config:       default y
 113 //config:       depends on TAR && FEATURE_TAR_LONG_OPTIONS
 114 //config:       help
 115 //config:         If you enable this option you'll be able to instruct tar to send
 116 //config:         the contents of each extracted file to the standard input of an
 117 //config:         external program.
 118 //config:
 119 //config:config FEATURE_TAR_UNAME_GNAME
 120 //config:       bool "Enable use of user and group names"
 121 //config:       default y
 122 //config:       depends on TAR
 123 //config:       help
 124 //config:         Enables use of user and group names in tar. This affects contents
 125 //config:         listings (-t) and preserving permissions when unpacking (-p).
 126 //config:         +200 bytes.
 127 //config:
 128 //config:config FEATURE_TAR_NOPRESERVE_TIME
 129 //config:       bool "Enable -m (do not preserve time) option"
 130 //config:       default y
 131 //config:       depends on TAR
 132 //config:       help
 133 //config:         With this option busybox supports GNU tar -m
 134 //config:         (do not preserve time) option.
 135 //config:
 136 //config:config FEATURE_TAR_SELINUX
 137 //config:       bool "Support for extracting SELinux labels"
 138 //config:       default n
 139 //config:       depends on TAR && SELINUX
 140 //config:       help
 141 //config:         With this option busybox supports restoring SELinux labels
 142 //config:         when extracting files from tar archives.
 143
 144 //applet:IF_TAR(APPLET(tar, BB_DIR_BIN, BB_SUID_DROP))
 145 //kbuild:lib-$(CONFIG_TAR) += tar.o
 146
 147 #include <fnmatch.h>
 148 #include "libbb.h"
 149 #include "bb_archive.h"
 150 /* FIXME: Stop using this non-standard feature */
 151 #ifndef FNM_LEADING_DIR
 152 # define FNM_LEADING_DIR 0
 153 #endif
 154
 155
 156 //#define DBG(fmt, ...) bb_error_msg("%s: " fmt, __func__, ## __VA_ARGS__)
 157 #define DBG(...) ((void)0)
 158
 159
 160 #define block_buf bb_common_bufsiz1
 161
 162
 163 #if !ENABLE_FEATURE_SEAMLESS_GZ && !ENABLE_FEATURE_SEAMLESS_BZ2
 164 /* Do not pass gzip flag to writeTarFile() */
 165 #define writeTarFile(tar_fd, verboseFlag, recurseFlags, include, exclude, gzip) \
 166         writeTarFile(tar_fd, verboseFlag, recurseFlags, include, exclude)
 167 #endif
 168
 169
 170 #if ENABLE_FEATURE_TAR_CREATE
 171
 172 /*
 173 ** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
 174 ** the only functions that deal with the HardLinkInfo structure.
 175 ** Even these functions use the xxxHardLinkInfo() functions.
 176 */
 177 typedef struct HardLinkInfo {
 178         struct HardLinkInfo *next; /* Next entry in list */
 179         dev_t dev;                 /* Device number */
 180         ino_t ino;                 /* Inode number */
 181 //      short linkCount;           /* (Hard) Link Count */
 182         char name[1];              /* Start of filename (must be last) */
 183 } HardLinkInfo;
 184
 185 /* Some info to be carried along when creating a new tarball */
 186 typedef struct TarBallInfo {
 187         int tarFd;                      /* Open-for-write file descriptor
 188                                          * for the tarball */
 189         int verboseFlag;                /* Whether to print extra stuff or not */
 190         const llist_t *excludeList;     /* List of files to not include */
 191         HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
 192         HardLinkInfo *hlInfo;           /* Hard Link Info for the current file */
 193 //TODO: save only st_dev + st_ino
 194         struct stat tarFileStatBuf;     /* Stat info for the tarball, letting
 195                                          * us know the inode and device that the
 196                                          * tarball lives, so we can avoid trying
 197                                          * to include the tarball into itself */
 198 } TarBallInfo;
 199
 200 /* A nice enum with all the possible tar file content types */
 201 enum {
 202         REGTYPE = '0',          /* regular file */
 203         REGTYPE0 = '\0',        /* regular file (ancient bug compat) */
 204         LNKTYPE = '1',          /* hard link */
 205         SYMTYPE = '2',          /* symbolic link */
 206         CHRTYPE = '3',          /* character special */
 207         BLKTYPE = '4',          /* block special */
 208         DIRTYPE = '5',          /* directory */
 209         FIFOTYPE = '6',         /* FIFO special */
 210         CONTTYPE = '7',         /* reserved */
 211         GNULONGLINK = 'K',      /* GNU long (>100 chars) link name */
 212         GNULONGNAME = 'L',      /* GNU long (>100 chars) file name */
 213 };
 214
 215 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
 216 static void addHardLinkInfo(HardLinkInfo **hlInfoHeadPtr,
 217                                         struct stat *statbuf,
 218                                         const char *fileName)
 219 {
 220         /* Note: hlInfoHeadPtr can never be NULL! */
 221         HardLinkInfo *hlInfo;
 222
 223         hlInfo = xmalloc(sizeof(HardLinkInfo) + strlen(fileName));
 224         hlInfo->next = *hlInfoHeadPtr;
 225         *hlInfoHeadPtr = hlInfo;
 226         hlInfo->dev = statbuf->st_dev;
 227         hlInfo->ino = statbuf->st_ino;
 228 //      hlInfo->linkCount = statbuf->st_nlink;
 229         strcpy(hlInfo->name, fileName);
 230 }
 231
 232 static void freeHardLinkInfo(HardLinkInfo **hlInfoHeadPtr)
 233 {
 234         HardLinkInfo *hlInfo;
 235         HardLinkInfo *hlInfoNext;
 236
 237         if (hlInfoHeadPtr) {
 238                 hlInfo = *hlInfoHeadPtr;
 239                 while (hlInfo) {
 240                         hlInfoNext = hlInfo->next;
 241                         free(hlInfo);
 242                         hlInfo = hlInfoNext;
 243                 }
 244                 *hlInfoHeadPtr = NULL;
 245         }
 246 }
 247
 248 /* Might be faster (and bigger) if the dev/ino were stored in numeric order ;) */
 249 static HardLinkInfo *findHardLinkInfo(HardLinkInfo *hlInfo, struct stat *statbuf)
 250 {
 251         while (hlInfo) {
 252                 if (statbuf->st_ino == hlInfo->ino
 253                  && statbuf->st_dev == hlInfo->dev
 254                 ) {
 255                         DBG("found hardlink:'%s'", hlInfo->name);
 256                         break;
 257                 }
 258                 hlInfo = hlInfo->next;
 259         }
 260         return hlInfo;
 261 }
 262
 263 /* Put an octal string into the specified buffer.
 264  * The number is zero padded and possibly null terminated.
 265  * Stores low-order bits only if whole value does not fit. */
 266 static void putOctal(char *cp, int len, off_t value)
 267 {
 268         char tempBuffer[sizeof(off_t)*3 + 1];
 269         char *tempString = tempBuffer;
 270         int width;
 271
 272         width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
 273         tempString += (width - len);
 274
 275         /* If string has leading zeroes, we can drop one */
 276         /* and field will have trailing '\0' */
 277         /* (increases chances of compat with other tars) */
 278         if (tempString[0] == '0')
 279                 tempString++;
 280
 281         /* Copy the string to the field */
 282         memcpy(cp, tempString, len);
 283 }
 284 #define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
 285
 286 static void chksum_and_xwrite(int fd, struct tar_header_t* hp)
 287 {
 288         /* POSIX says that checksum is done on unsigned bytes
 289          * (Sun and HP-UX gets it wrong... more details in
 290          * GNU tar source) */
 291         const unsigned char *cp;
 292         int chksum, size;
 293
 294         strcpy(hp->magic, "ustar  ");
 295
 296         /* Calculate and store the checksum (i.e., the sum of all of the bytes of
 297          * the header).  The checksum field must be filled with blanks for the
 298          * calculation.  The checksum field is formatted differently from the
 299          * other fields: it has 6 digits, a null, then a space -- rather than
 300          * digits, followed by a null like the other fields... */
 301         memset(hp->chksum, ' ', sizeof(hp->chksum));
 302         cp = (const unsigned char *) hp;
 303         chksum = 0;
 304         size = sizeof(*hp);
 305         do { chksum += *cp++; } while (--size);
 306         putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);
 307
 308         /* Now write the header out to disk */
 309         xwrite(fd, hp, sizeof(*hp));
 310 }
 311
 312 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 313 static void writeLongname(int fd, int type, const char *name, int dir)
 314 {
 315         static const struct {
 316                 char mode[8];             /* 100-107 */
 317                 char uid[8];              /* 108-115 */
 318                 char gid[8];              /* 116-123 */
 319                 char size[12];            /* 124-135 */
 320                 char mtime[12];           /* 136-147 */
 321         } prefilled = {
 322                 "0000000",
 323                 "0000000",
 324                 "0000000",
 325                 "00000000000",
 326                 "00000000000",
 327         };
 328         struct tar_header_t header;
 329         int size;
 330
 331         dir = !!dir; /* normalize: 0/1 */
 332         size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
 333         /* + dir: account for possible '/' */
 334
 335         memset(&header, 0, sizeof(header));
 336         strcpy(header.name, "././@LongLink");
 337         memcpy(header.mode, prefilled.mode, sizeof(prefilled));
 338         PUT_OCTAL(header.size, size);
 339         header.typeflag = type;
 340         chksum_and_xwrite(fd, &header);
 341
 342         /* Write filename[/] and pad the block. */
 343         /* dir=0: writes 'name<NUL>', pads */
 344         /* dir=1: writes 'name', writes '/<NUL>', pads */
 345         dir *= 2;
 346         xwrite(fd, name, size - dir);
 347         xwrite(fd, "/", dir);
 348         size = (-size) & (TAR_BLOCK_SIZE-1);
 349         memset(&header, 0, size);
 350         xwrite(fd, &header, size);
 351 }
 352 #endif
 353
 354 /* Write out a tar header for the specified file/directory/whatever */
 355 static int writeTarHeader(struct TarBallInfo *tbInfo,
 356                 const char *header_name, const char *fileName, struct stat *statbuf)
 357 {
 358         struct tar_header_t header;
 359
 360         memset(&header, 0, sizeof(header));
 361
 362         strncpy(header.name, header_name, sizeof(header.name));
 363
 364         /* POSIX says to mask mode with 07777. */
 365         PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
 366         PUT_OCTAL(header.uid, statbuf->st_uid);
 367         PUT_OCTAL(header.gid, statbuf->st_gid);
 368         memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
 369         /* users report that files with negative st_mtime cause trouble, so: */
 370         PUT_OCTAL(header.mtime, statbuf->st_mtime >= 0 ? statbuf->st_mtime : 0);
 371
 372         /* Enter the user and group names */
 373         safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
 374         safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
 375
 376         if (tbInfo->hlInfo) {
 377                 /* This is a hard link */
 378                 header.typeflag = LNKTYPE;
 379                 strncpy(header.linkname, tbInfo->hlInfo->name,
 380                                 sizeof(header.linkname));
 381 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 382                 /* Write out long linkname if needed */
 383                 if (header.linkname[sizeof(header.linkname)-1])
 384                         writeLongname(tbInfo->tarFd, GNULONGLINK,
 385                                         tbInfo->hlInfo->name, 0);
 386 #endif
 387         } else if (S_ISLNK(statbuf->st_mode)) {
 388                 char *lpath = xmalloc_readlink_or_warn(fileName);
 389                 if (!lpath)
 390                         return FALSE;
 391                 header.typeflag = SYMTYPE;
 392                 strncpy(header.linkname, lpath, sizeof(header.linkname));
 393 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 394                 /* Write out long linkname if needed */
 395                 if (header.linkname[sizeof(header.linkname)-1])
 396                         writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
 397 #else
 398                 /* If it is larger than 100 bytes, bail out */
 399                 if (header.linkname[sizeof(header.linkname)-1]) {
 400                         free(lpath);
 401                         bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 402                         return FALSE;
 403                 }
 404 #endif
 405                 free(lpath);
 406         } else if (S_ISDIR(statbuf->st_mode)) {
 407                 header.typeflag = DIRTYPE;
 408                 /* Append '/' only if there is a space for it */
 409                 if (!header.name[sizeof(header.name)-1])
 410                         header.name[strlen(header.name)] = '/';
 411         } else if (S_ISCHR(statbuf->st_mode)) {
 412                 header.typeflag = CHRTYPE;
 413                 PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
 414                 PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 415         } else if (S_ISBLK(statbuf->st_mode)) {
 416                 header.typeflag = BLKTYPE;
 417                 PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
 418                 PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 419         } else if (S_ISFIFO(statbuf->st_mode)) {
 420                 header.typeflag = FIFOTYPE;
 421         } else if (S_ISREG(statbuf->st_mode)) {
 422                 /* header.size field is 12 bytes long */
 423                 /* Does octal-encoded size fit? */
 424                 uoff_t filesize = statbuf->st_size;
 425                 if (sizeof(filesize) <= 4
 426                  || filesize <= (uoff_t)0777777777777LL
 427                 ) {
 428                         PUT_OCTAL(header.size, filesize);
 429                 }
 430                 /* Does base256-encoded size fit?
 431                  * It always does unless off_t is wider than 64 bits.
 432                  */
 433                 else if (ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 434 #if ULLONG_MAX > 0xffffffffffffffffLL /* 2^64-1 */
 435                  && (filesize <= 0x3fffffffffffffffffffffffLL)
 436 #endif
 437                 ) {
 438                         /* GNU tar uses "base-256 encoding" for very large numbers.
 439                          * Encoding is binary, with highest bit always set as a marker
 440                          * and sign in next-highest bit:
 441                          * 80 00 .. 00 - zero
 442                          * bf ff .. ff - largest positive number
 443                          * ff ff .. ff - minus 1
 444                          * c0 00 .. 00 - smallest negative number
 445                          */
 446                         char *p8 = header.size + sizeof(header.size);
 447                         do {
 448                                 *--p8 = (uint8_t)filesize;
 449                                 filesize >>= 8;
 450                         } while (p8 != header.size);
 451                         *p8 |= 0x80;
 452                 } else {
 453                         bb_error_msg_and_die("can't store file '%s' "
 454                                 "of size %"OFF_FMT"u, aborting",
 455                                 fileName, statbuf->st_size);
 456                 }
 457                 header.typeflag = REGTYPE;
 458         } else {
 459                 bb_error_msg("%s: unknown file type", fileName);
 460                 return FALSE;
 461         }
 462
 463 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 464         /* Write out long name if needed */
 465         /* (we, like GNU tar, output long linkname *before* long name) */
 466         if (header.name[sizeof(header.name)-1])
 467                 writeLongname(tbInfo->tarFd, GNULONGNAME,
 468                                 header_name, S_ISDIR(statbuf->st_mode));
 469 #endif
 470
 471         /* Now write the header out to disk */
 472         chksum_and_xwrite(tbInfo->tarFd, &header);
 473
 474         /* Now do the verbose thing (or not) */
 475         if (tbInfo->verboseFlag) {
 476                 FILE *vbFd = stdout;
 477
 478                 /* If archive goes to stdout, verbose goes to stderr */
 479                 if (tbInfo->tarFd == STDOUT_FILENO)
 480                         vbFd = stderr;
 481                 /* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
 482                 /* We don't have such excesses here: for us "v" == "vv" */
 483                 /* '/' is probably a GNUism */
 484                 fprintf(vbFd, "%s%s\n", header_name,
 485                                 S_ISDIR(statbuf->st_mode) ? "/" : "");
 486         }
 487
 488         return TRUE;
 489 }
 490
 491 #if ENABLE_FEATURE_TAR_FROM
 492 static int exclude_file(const llist_t *excluded_files, const char *file)
 493 {
 494         while (excluded_files) {
 495                 if (excluded_files->data[0] == '/') {
 496                         if (fnmatch(excluded_files->data, file,
 497                                         FNM_PATHNAME | FNM_LEADING_DIR) == 0)
 498                                 return 1;
 499                 } else {
 500                         const char *p;
 501
 502                         for (p = file; p[0] != '\0'; p++) {
 503                                 if ((p == file || p[-1] == '/')
 504                                  && p[0] != '/'
 505                                  && fnmatch(excluded_files->data, p,
 506                                                 FNM_PATHNAME | FNM_LEADING_DIR) == 0
 507                                 ) {
 508                                         return 1;
 509                                 }
 510                         }
 511                 }
 512                 excluded_files = excluded_files->link;
 513         }
 514
 515         return 0;
 516 }
 517 #else
 518 # define exclude_file(excluded_files, file) 0
 519 #endif
 520
 521 static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statbuf,
 522                         void *userData, int depth UNUSED_PARAM)
 523 {
 524         struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
 525         const char *header_name;
 526         int inputFileFd = -1;
 527
 528         DBG("writeFileToTarball('%s')", fileName);
 529
 530         /* Strip leading '/' and such (must be before memorizing hardlink's name) */
 531         header_name = strip_unsafe_prefix(fileName);
 532
 533         if (header_name[0] == '\0')
 534                 return TRUE;
 535
 536         /* It is against the rules to archive a socket */
 537         if (S_ISSOCK(statbuf->st_mode)) {
 538                 bb_error_msg("%s: socket ignored", fileName);
 539                 return TRUE;
 540         }
 541
 542         /*
 543          * Check to see if we are dealing with a hard link.
 544          * If so -
 545          * Treat the first occurance of a given dev/inode as a file while
 546          * treating any additional occurances as hard links.  This is done
 547          * by adding the file information to the HardLinkInfo linked list.
 548          */
 549         tbInfo->hlInfo = NULL;
 550         if (!S_ISDIR(statbuf->st_mode) && statbuf->st_nlink > 1) {
 551                 DBG("'%s': st_nlink > 1", header_name);
 552                 tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
 553                 if (tbInfo->hlInfo == NULL) {
 554                         DBG("'%s': addHardLinkInfo", header_name);
 555                         addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, header_name);
 556                 }
 557         }
 558
 559         /* It is a bad idea to store the archive we are in the process of creating,
 560          * so check the device and inode to be sure that this particular file isn't
 561          * the new tarball */
 562         if (tbInfo->tarFileStatBuf.st_dev == statbuf->st_dev
 563          && tbInfo->tarFileStatBuf.st_ino == statbuf->st_ino
 564         ) {
 565                 bb_error_msg("%s: file is the archive; skipping", fileName);
 566                 return TRUE;
 567         }
 568
 569         if (exclude_file(tbInfo->excludeList, header_name))
 570                 return SKIP;
 571
 572 #if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 573         if (strlen(header_name) >= NAME_SIZE) {
 574                 bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 575                 return TRUE;
 576         }
 577 #endif
 578
 579         /* Is this a regular file? */
 580         if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
 581                 /* open the file we want to archive, and make sure all is well */
 582                 inputFileFd = open_or_warn(fileName, O_RDONLY);
 583                 if (inputFileFd < 0) {
 584                         return FALSE;
 585                 }
 586         }
 587
 588         /* Add an entry to the tarball */
 589         if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
 590                 return FALSE;
 591         }
 592
 593         /* If it was a regular file, write out the body */
 594         if (inputFileFd >= 0) {
 595                 size_t readSize;
 596                 /* Write the file to the archive. */
 597                 /* We record size into header first, */
 598                 /* and then write out file. If file shrinks in between, */
 599                 /* tar will be corrupted. So we don't allow for that. */
 600                 /* NB: GNU tar 1.16 warns and pads with zeroes */
 601                 /* or even seeks back and updates header */
 602                 bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
 603                 ////off_t readSize;
 604                 ////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
 605                 ////if (readSize != statbuf->st_size && readSize >= 0) {
 606                 ////    bb_error_msg_and_die("short read from %s, aborting", fileName);
 607                 ////}
 608
 609                 /* Check that file did not grow in between? */
 610                 /* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
 611
 612                 close(inputFileFd);
 613
 614                 /* Pad the file up to the tar block size */
 615                 /* (a few tricks here in the name of code size) */
 616                 readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
 617                 memset(block_buf, 0, readSize);
 618                 xwrite(tbInfo->tarFd, block_buf, readSize);
 619         }
 620
 621         return TRUE;
 622 }
 623
 624 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 625 # if !(ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2)
 626 #  define vfork_compressor(tar_fd, gzip) vfork_compressor(tar_fd)
 627 # endif
 628 /* Don't inline: vfork scares gcc and pessimizes code */
 629 static void NOINLINE vfork_compressor(int tar_fd, int gzip)
 630 {
 631         pid_t gzipPid;
 632 # if ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2
 633         const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
 634 # elif ENABLE_FEATURE_SEAMLESS_GZ
 635         const char *zip_exec = "gzip";
 636 # else /* only ENABLE_FEATURE_SEAMLESS_BZ2 */
 637         const char *zip_exec = "bzip2";
 638 # endif
 639         // On Linux, vfork never unpauses parent early, although standard
 640         // allows for that. Do we want to waste bytes checking for it?
 641 # define WAIT_FOR_CHILD 0
 642         volatile int vfork_exec_errno = 0;
 643         struct fd_pair gzipDataPipe;
 644 # if WAIT_FOR_CHILD
 645         struct fd_pair gzipStatusPipe;
 646         xpiped_pair(gzipStatusPipe);
 647 # endif
 648         xpiped_pair(gzipDataPipe);
 649
 650         signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
 651
 652 # if defined(__GNUC__) && __GNUC__
 653         /* Avoid vfork clobbering */
 654         (void) &zip_exec;
 655 # endif
 656
 657         gzipPid = xvfork();
 658
 659         if (gzipPid == 0) {
 660                 /* child */
 661                 /* NB: close _first_, then move fds! */
 662                 close(gzipDataPipe.wr);
 663 # if WAIT_FOR_CHILD
 664                 close(gzipStatusPipe.rd);
 665                 /* gzipStatusPipe.wr will close only on exec -
 666                  * parent waits for this close to happen */
 667                 fcntl(gzipStatusPipe.wr, F_SETFD, FD_CLOEXEC);
 668 # endif
 669                 xmove_fd(gzipDataPipe.rd, 0);
 670                 xmove_fd(tar_fd, 1);
 671                 /* exec gzip/bzip2 program/applet */
 672                 BB_EXECLP(zip_exec, zip_exec, "-f", (char *)0);
 673                 vfork_exec_errno = errno;
 674                 _exit(EXIT_FAILURE);
 675         }
 676
 677         /* parent */
 678         xmove_fd(gzipDataPipe.wr, tar_fd);
 679         close(gzipDataPipe.rd);
 680 # if WAIT_FOR_CHILD
 681         close(gzipStatusPipe.wr);
 682         while (1) {
 683                 char buf;
 684                 int n;
 685
 686                 /* Wait until child execs (or fails to) */
 687                 n = full_read(gzipStatusPipe.rd, &buf, 1);
 688                 if (n < 0 /* && errno == EAGAIN */)
 689                         continue;       /* try it again */
 690         }
 691         close(gzipStatusPipe.rd);
 692 # endif
 693         if (vfork_exec_errno) {
 694                 errno = vfork_exec_errno;
 695                 bb_perror_msg_and_die("can't execute '%s'", zip_exec);
 696         }
 697 }
 698 #endif /* ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2 */
 699
 700
 701 /* gcc 4.2.1 inlines it, making code bigger */
 702 static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
 703         int recurseFlags, const llist_t *include,
 704         const llist_t *exclude, int gzip)
 705 {
 706         int errorFlag = FALSE;
 707         struct TarBallInfo tbInfo;
 708
 709         tbInfo.hlInfoHead = NULL;
 710         tbInfo.tarFd = tar_fd;
 711         tbInfo.verboseFlag = verboseFlag;
 712
 713         /* Store the stat info for the tarball's file, so
 714          * can avoid including the tarball into itself....  */
 715         xfstat(tbInfo.tarFd, &tbInfo.tarFileStatBuf, "can't stat tar file");
 716
 717 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 718         if (gzip)
 719                 vfork_compressor(tbInfo.tarFd, gzip);
 720 #endif
 721
 722         tbInfo.excludeList = exclude;
 723
 724         /* Read the directory/files and iterate over them one at a time */
 725         while (include) {
 726                 if (!recursive_action(include->data, recurseFlags,
 727                                 writeFileToTarball, writeFileToTarball, &tbInfo, 0)
 728                 ) {
 729                         errorFlag = TRUE;
 730                 }
 731                 include = include->link;
 732         }
 733         /* Write two empty blocks to the end of the archive */
 734         memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
 735         xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
 736
 737         /* To be pedantically correct, we would check if the tarball
 738          * is smaller than 20 tar blocks, and pad it if it was smaller,
 739          * but that isn't necessary for GNU tar interoperability, and
 740          * so is considered a waste of space */
 741
 742         /* Close so the child process (if any) will exit */
 743         close(tbInfo.tarFd);
 744
 745         /* Hang up the tools, close up shop, head home */
 746         if (ENABLE_FEATURE_CLEAN_UP)
 747                 freeHardLinkInfo(&tbInfo.hlInfoHead);
 748
 749         if (errorFlag)
 750                 bb_error_msg("error exit delayed from previous errors");
 751
 752 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 753         if (gzip) {
 754                 int status;
 755                 if (safe_waitpid(-1, &status, 0) == -1)
 756                         bb_perror_msg("waitpid");
 757                 else if (!WIFEXITED(status) || WEXITSTATUS(status))
 758                         /* gzip was killed or has exited with nonzero! */
 759                         errorFlag = TRUE;
 760         }
 761 #endif
 762         return errorFlag;
 763 }
 764 #else
 765 int writeTarFile(int tar_fd, int verboseFlag,
 766         int recurseFlags, const llist_t *include,
 767         const llist_t *exclude, int gzip);
 768 #endif /* FEATURE_TAR_CREATE */
 769
 770 #if ENABLE_FEATURE_TAR_FROM
 771 static llist_t *append_file_list_to_list(llist_t *list)
 772 {
 773         FILE *src_stream;
 774         char *line;
 775         llist_t *newlist = NULL;
 776
 777         while (list) {
 778                 src_stream = xfopen_stdin(llist_pop(&list));
 779                 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
 780                         /* kill trailing '/' unless the string is just "/" */
 781                         char *cp = last_char_is(line, '/');
 782                         if (cp > line)
 783                                 *cp = '\0';
 784                         llist_add_to_end(&newlist, line);
 785                 }
 786                 fclose(src_stream);
 787         }
 788         return newlist;
 789 }
 790 #endif
 791
 792 //usage:#define tar_trivial_usage
 793 //usage:        "-[" IF_FEATURE_TAR_CREATE("c") "xt"
 794 //usage:        IF_FEATURE_SEAMLESS_Z("Z")
 795 //usage:        IF_FEATURE_SEAMLESS_GZ("z")
 796 //usage:        IF_FEATURE_SEAMLESS_XZ("J")
 797 //usage:        IF_FEATURE_SEAMLESS_BZ2("j")
 798 //usage:        IF_FEATURE_SEAMLESS_LZMA("a")
 799 //usage:        IF_FEATURE_TAR_CREATE("h")
 800 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 801 //usage:        "vO] "
 802 //usage:        IF_FEATURE_TAR_FROM("[-X FILE] [-T FILE] ")
 803 //usage:        "[-f TARFILE] [-C DIR] [FILE]..."
 804 //usage:#define tar_full_usage "\n\n"
 805 //usage:        IF_FEATURE_TAR_CREATE("Create, extract, ")
 806 //usage:        IF_NOT_FEATURE_TAR_CREATE("Extract ")
 807 //usage:        "or list files from a tar file\n"
 808 //usage:     "\nOperation:"
 809 //usage:        IF_FEATURE_TAR_CREATE(
 810 //usage:     "\n        c       Create"
 811 //usage:        )
 812 //usage:     "\n        x       Extract"
 813 //usage:     "\n        t       List"
 814 //usage:     "\n        f       Name of TARFILE ('-' for stdin/out)"
 815 //usage:     "\n        C       Change to DIR before operation"
 816 //usage:     "\n        v       Verbose"
 817 //usage:        IF_FEATURE_SEAMLESS_Z(
 818 //usage:     "\n        Z       (De)compress using compress"
 819 //usage:        )
 820 //usage:        IF_FEATURE_SEAMLESS_GZ(
 821 //usage:     "\n        z       (De)compress using gzip"
 822 //usage:        )
 823 //usage:        IF_FEATURE_SEAMLESS_XZ(
 824 //usage:     "\n        J       (De)compress using xz"
 825 //usage:        )
 826 //usage:        IF_FEATURE_SEAMLESS_BZ2(
 827 //usage:     "\n        j       (De)compress using bzip2"
 828 //usage:        )
 829 //usage:        IF_FEATURE_SEAMLESS_LZMA(
 830 //usage:     "\n        a       (De)compress using lzma"
 831 //usage:        )
 832 //usage:     "\n        O       Extract to stdout"
 833 //usage:        IF_FEATURE_TAR_CREATE(
 834 //usage:     "\n        h       Follow symlinks"
 835 //usage:        )
 836 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME(
 837 //usage:     "\n        m       Don't restore mtime"
 838 //usage:        )
 839 //usage:        IF_FEATURE_TAR_FROM(
 840 //usage:        IF_FEATURE_TAR_LONG_OPTIONS(
 841 //usage:     "\n        exclude File to exclude"
 842 //usage:        )
 843 //usage:     "\n        X       File with names to exclude"
 844 //usage:     "\n        T       File with names to include"
 845 //usage:        )
 846 //usage:
 847 //usage:#define tar_example_usage
 848 //usage:       "$ zcat /tmp/tarball.tar.gz | tar -xf -\n"
 849 //usage:       "$ tar -cf /tmp/tarball.tar /usr/local\n"
 850
 851 // Supported but aren't in --help:
 852 //      o       no-same-owner
 853 //      p       same-permissions
 854 //      k       keep-old
 855 //      no-recursion
 856 //      numeric-owner
 857 //      no-same-permissions
 858 //      overwrite
 859 //IF_FEATURE_TAR_TO_COMMAND(
 860 //      to-command
 861 //)
 862
 863 enum {
 864         OPTBIT_KEEP_OLD = 8,
 865         IF_FEATURE_TAR_CREATE(   OPTBIT_CREATE      ,)
 866         IF_FEATURE_TAR_CREATE(   OPTBIT_DEREFERENCE ,)
 867         IF_FEATURE_SEAMLESS_BZ2( OPTBIT_BZIP2       ,)
 868         IF_FEATURE_SEAMLESS_LZMA(OPTBIT_LZMA        ,)
 869         IF_FEATURE_TAR_FROM(     OPTBIT_INCLUDE_FROM,)
 870         IF_FEATURE_TAR_FROM(     OPTBIT_EXCLUDE_FROM,)
 871         IF_FEATURE_SEAMLESS_GZ(  OPTBIT_GZIP        ,)
 872         IF_FEATURE_SEAMLESS_XZ(  OPTBIT_XZ          ,) // 16th bit
 873         IF_FEATURE_SEAMLESS_Z(   OPTBIT_COMPRESS    ,)
 874         IF_FEATURE_TAR_NOPRESERVE_TIME(OPTBIT_NOPRESERVE_TIME,)
 875 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 876         OPTBIT_NORECURSION,
 877         IF_FEATURE_TAR_TO_COMMAND(OPTBIT_2COMMAND   ,)
 878         OPTBIT_NUMERIC_OWNER,
 879         OPTBIT_NOPRESERVE_PERM,
 880         OPTBIT_OVERWRITE,
 881 #endif
 882         OPT_TEST         = 1 << 0, // t
 883         OPT_EXTRACT      = 1 << 1, // x
 884         OPT_BASEDIR      = 1 << 2, // C
 885         OPT_TARNAME      = 1 << 3, // f
 886         OPT_2STDOUT      = 1 << 4, // O
 887         OPT_NOPRESERVE_OWNER = 1 << 5, // o == no-same-owner
 888         OPT_P            = 1 << 6, // p
 889         OPT_VERBOSE      = 1 << 7, // v
 890         OPT_KEEP_OLD     = 1 << 8, // k
 891         OPT_CREATE       = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_CREATE      )) + 0, // c
 892         OPT_DEREFERENCE  = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_DEREFERENCE )) + 0, // h
 893         OPT_BZIP2        = IF_FEATURE_SEAMLESS_BZ2( (1 << OPTBIT_BZIP2       )) + 0, // j
 894         OPT_LZMA         = IF_FEATURE_SEAMLESS_LZMA((1 << OPTBIT_LZMA        )) + 0, // a
 895         OPT_INCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_INCLUDE_FROM)) + 0, // T
 896         OPT_EXCLUDE_FROM = IF_FEATURE_TAR_FROM(     (1 << OPTBIT_EXCLUDE_FROM)) + 0, // X
 897         OPT_GZIP         = IF_FEATURE_SEAMLESS_GZ(  (1 << OPTBIT_GZIP        )) + 0, // z
 898         OPT_XZ           = IF_FEATURE_SEAMLESS_XZ(  (1 << OPTBIT_XZ          )) + 0, // J
 899         OPT_COMPRESS     = IF_FEATURE_SEAMLESS_Z(   (1 << OPTBIT_COMPRESS    )) + 0, // Z
 900         OPT_NOPRESERVE_TIME = IF_FEATURE_TAR_NOPRESERVE_TIME((1 << OPTBIT_NOPRESERVE_TIME)) + 0, // m
 901         OPT_NORECURSION     = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NORECURSION    )) + 0, // no-recursion
 902         OPT_2COMMAND        = IF_FEATURE_TAR_TO_COMMAND(  (1 << OPTBIT_2COMMAND       )) + 0, // to-command
 903         OPT_NUMERIC_OWNER   = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NUMERIC_OWNER  )) + 0, // numeric-owner
 904         OPT_NOPRESERVE_PERM = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOPRESERVE_PERM)) + 0, // no-same-permissions
 905         OPT_OVERWRITE       = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_OVERWRITE      )) + 0, // overwrite
 906
 907         OPT_ANY_COMPRESS = (OPT_BZIP2 | OPT_LZMA | OPT_GZIP | OPT_XZ | OPT_COMPRESS),
 908 };
 909 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 910 static const char tar_longopts[] ALIGN1 =
 911         "list\0"                No_argument       "t"
 912         "extract\0"             No_argument       "x"
 913         "directory\0"           Required_argument "C"
 914         "file\0"                Required_argument "f"
 915         "to-stdout\0"           No_argument       "O"
 916         /* do not restore owner */
 917         /* Note: GNU tar handles 'o' as no-same-owner only on extract,
 918          * on create, 'o' is --old-archive. We do not support --old-archive. */
 919         "no-same-owner\0"       No_argument       "o"
 920         "same-permissions\0"    No_argument       "p"
 921         "verbose\0"             No_argument       "v"
 922         "keep-old\0"            No_argument       "k"
 923 # if ENABLE_FEATURE_TAR_CREATE
 924         "create\0"              No_argument       "c"
 925         "dereference\0"         No_argument       "h"
 926 # endif
 927 # if ENABLE_FEATURE_SEAMLESS_BZ2
 928         "bzip2\0"               No_argument       "j"
 929 # endif
 930 # if ENABLE_FEATURE_SEAMLESS_LZMA
 931         "lzma\0"                No_argument       "a"
 932 # endif
 933 # if ENABLE_FEATURE_TAR_FROM
 934         "files-from\0"          Required_argument "T"
 935         "exclude-from\0"        Required_argument "X"
 936 # endif
 937 # if ENABLE_FEATURE_SEAMLESS_GZ
 938         "gzip\0"                No_argument       "z"
 939 # endif
 940 # if ENABLE_FEATURE_SEAMLESS_XZ
 941         "xz\0"                  No_argument       "J"
 942 # endif
 943 # if ENABLE_FEATURE_SEAMLESS_Z
 944         "compress\0"            No_argument       "Z"
 945 # endif
 946 # if ENABLE_FEATURE_TAR_NOPRESERVE_TIME
 947         "touch\0"               No_argument       "m"
 948 # endif
 949         "no-recursion\0"        No_argument       "\xfa"
 950 # if ENABLE_FEATURE_TAR_TO_COMMAND
 951         "to-command\0"          Required_argument "\xfb"
 952 # endif
 953         /* use numeric uid/gid from tar header, not textual */
 954         "numeric-owner\0"       No_argument       "\xfc"
 955         /* do not restore mode */
 956         "no-same-permissions\0" No_argument       "\xfd"
 957         /* on unpack, open with O_TRUNC and !O_EXCL */
 958         "overwrite\0"           No_argument       "\xfe"
 959         /* --exclude takes next bit position in option mask, */
 960         /* therefore we have to put it _after_ --no-same-permissions */
 961 # if ENABLE_FEATURE_TAR_FROM
 962         "exclude\0"             Required_argument "\xff"
 963 # endif
 964         ;
 965 #endif
 966
 967 int tar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 968 int tar_main(int argc UNUSED_PARAM, char **argv)
 969 {
 970         archive_handle_t *tar_handle;
 971         char *base_dir = NULL;
 972         const char *tar_filename = "-";
 973         unsigned opt;
 974         int verboseFlag = 0;
 975 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 976         llist_t *excludes = NULL;
 977 #endif
 978
 979         /* Initialise default values */
 980         tar_handle = init_handle();
 981         tar_handle->ah_flags = ARCHIVE_CREATE_LEADING_DIRS
 982                              | ARCHIVE_RESTORE_DATE
 983                              | ARCHIVE_UNLINK_OLD;
 984
 985         /* Apparently only root's tar preserves perms (see bug 3844) */
 986         if (getuid() != 0)
 987                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
 988
 989         /* Prepend '-' to the first argument if required */
 990         opt_complementary = "--:" // first arg is options
 991                 "tt:vv:" // count -t,-v
 992                 IF_FEATURE_TAR_FROM("X::T::") // cumulative lists
 993 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 994                 "\xff::" // cumulative lists for --exclude
 995 #endif
 996                 IF_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
 997                 IF_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
 998                 IF_NOT_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
 999 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
1000         applet_long_options = tar_longopts;
1001 #endif
1002 #if ENABLE_DESKTOP
1003         if (argv[1] && argv[1][0] != '-') {
1004                 /* Compat:
1005                  * 1st argument without dash handles options with parameters
1006                  * differently from dashed one: it takes *next argv[i]*
1007                  * as paramenter even if there are more chars in 1st argument:
1008                  *  "tar fx TARFILE" - "x" is not taken as f's param
1009                  *  but is interpreted as -x option
1010                  *  "tar -xf TARFILE" - dashed equivalent of the above
1011                  *  "tar -fx ..." - "x" is taken as f's param
1012                  * getopt32 wouldn't handle 1st command correctly.
1013                  * Unfortunately, people do use such commands.
1014                  * We massage argv[1] to work around it by moving 'f'
1015                  * to the end of the string.
1016                  * More contrived "tar fCx TARFILE DIR" still fails,
1017                  * but such commands are much less likely to be used.
1018                  */
1019                 char *f = strchr(argv[1], 'f');
1020                 if (f) {
1021                         while (f[1] != '\0') {
1022                                 *f = f[1];
1023                                 f++;
1024                         }
1025                         *f = 'f';
1026                 }
1027         }
1028 #endif
1029         opt = getopt32(argv,
1030                 "txC:f:Oopvk"
1031                 IF_FEATURE_TAR_CREATE(   "ch"  )
1032                 IF_FEATURE_SEAMLESS_BZ2( "j"   )
1033                 IF_FEATURE_SEAMLESS_LZMA("a"   )
1034                 IF_FEATURE_TAR_FROM(     "T:X:")
1035                 IF_FEATURE_SEAMLESS_GZ(  "z"   )
1036                 IF_FEATURE_SEAMLESS_XZ(  "J"   )
1037                 IF_FEATURE_SEAMLESS_Z(   "Z"   )
1038                 IF_FEATURE_TAR_NOPRESERVE_TIME("m")
1039                 , &base_dir // -C dir
1040                 , &tar_filename // -f filename
1041                 IF_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
1042                 IF_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
1043                 IF_FEATURE_TAR_TO_COMMAND(, &(tar_handle->tar__to_command)) // --to-command
1044 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
1045                 , &excludes // --exclude
1046 #endif
1047                 , &verboseFlag // combined count for -t and -v
1048                 , &verboseFlag // combined count for -t and -v
1049                 );
1050         //bb_error_msg("opt:%08x", opt);
1051         argv += optind;
1052
1053         if (verboseFlag) tar_handle->action_header = header_verbose_list;
1054         if (verboseFlag == 1) tar_handle->action_header = header_list;
1055
1056         if (opt & OPT_EXTRACT)
1057                 tar_handle->action_data = data_extract_all;
1058
1059         if (opt & OPT_2STDOUT)
1060                 tar_handle->action_data = data_extract_to_stdout;
1061
1062         if (opt & OPT_2COMMAND) {
1063                 putenv((char*)"TAR_FILETYPE=f");
1064                 signal(SIGPIPE, SIG_IGN);
1065                 tar_handle->action_data = data_extract_to_command;
1066                 IF_FEATURE_TAR_TO_COMMAND(tar_handle->tar__to_command_shell = xstrdup(get_shell_name());)
1067         }
1068
1069         if (opt & OPT_KEEP_OLD)
1070                 tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
1071
1072         if (opt & OPT_NUMERIC_OWNER)
1073                 tar_handle->ah_flags |= ARCHIVE_NUMERIC_OWNER;
1074
1075         if (opt & OPT_NOPRESERVE_OWNER)
1076                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_OWNER;
1077
1078         if (opt & OPT_NOPRESERVE_PERM)
1079                 tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
1080
1081         if (opt & OPT_OVERWRITE) {
1082                 tar_handle->ah_flags &= ~ARCHIVE_UNLINK_OLD;
1083                 tar_handle->ah_flags |= ARCHIVE_O_TRUNC;
1084         }
1085
1086         if (opt & OPT_NOPRESERVE_TIME)
1087                 tar_handle->ah_flags &= ~ARCHIVE_RESTORE_DATE;
1088
1089 #if ENABLE_FEATURE_TAR_FROM
1090         tar_handle->reject = append_file_list_to_list(tar_handle->reject);
1091 # if ENABLE_FEATURE_TAR_LONG_OPTIONS
1092         /* Append excludes to reject */
1093         while (excludes) {
1094                 llist_t *next = excludes->link;
1095                 excludes->link = tar_handle->reject;
1096                 tar_handle->reject = excludes;
1097                 excludes = next;
1098         }
1099 # endif
1100         tar_handle->accept = append_file_list_to_list(tar_handle->accept);
1101 #endif
1102
1103         /* Setup an array of filenames to work with */
1104         /* TODO: This is the same as in ar, make a separate function? */
1105         while (*argv) {
1106                 /* kill trailing '/' unless the string is just "/" */
1107                 char *cp = last_char_is(*argv, '/');
1108                 if (cp > *argv)
1109                         *cp = '\0';
1110                 llist_add_to_end(&tar_handle->accept, *argv);
1111                 argv++;
1112         }
1113
1114         if (tar_handle->accept || tar_handle->reject)
1115                 tar_handle->filter = filter_accept_reject_list;
1116
1117         /* Open the tar file */
1118         {
1119                 int tar_fd = STDIN_FILENO;
1120                 int flags = O_RDONLY;
1121
1122                 if (opt & OPT_CREATE) {
1123                         /* Make sure there is at least one file to tar up */
1124                         if (tar_handle->accept == NULL)
1125                                 bb_error_msg_and_die("empty archive");
1126
1127                         tar_fd = STDOUT_FILENO;
1128                         /* Mimicking GNU tar 1.15.1: */
1129                         flags = O_WRONLY | O_CREAT | O_TRUNC;
1130                 }
1131
1132                 if (LONE_DASH(tar_filename)) {
1133                         tar_handle->src_fd = tar_fd;
1134                         tar_handle->seek = seek_by_read;
1135                 } else {
1136                         if (ENABLE_FEATURE_TAR_AUTODETECT
1137                          && flags == O_RDONLY
1138                          && !(opt & OPT_ANY_COMPRESS)
1139                         ) {
1140                                 tar_handle->src_fd = open_zipped(tar_filename);
1141                                 if (tar_handle->src_fd < 0)
1142                                         bb_perror_msg_and_die("can't open '%s'", tar_filename);
1143                         } else {
1144                                 tar_handle->src_fd = xopen(tar_filename, flags);
1145                         }
1146                 }
1147         }
1148
1149         if (base_dir)
1150                 xchdir(base_dir);
1151
1152         //if (SEAMLESS_COMPRESSION || OPT_COMPRESS)
1153         //      /* We need to know whether child (gzip/bzip/etc) exits abnormally */
1154         //      signal(SIGCHLD, check_errors_in_children);
1155
1156         /* Create an archive */
1157         if (opt & OPT_CREATE) {
1158 #if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
1159                 int zipMode = 0;
1160                 if (ENABLE_FEATURE_SEAMLESS_GZ && (opt & OPT_GZIP))
1161                         zipMode = 1;
1162                 if (ENABLE_FEATURE_SEAMLESS_BZ2 && (opt & OPT_BZIP2))
1163                         zipMode = 2;
1164 #endif
1165                 /* NB: writeTarFile() closes tar_handle->src_fd */
1166                 return writeTarFile(tar_handle->src_fd, verboseFlag,
1167                                 (opt & OPT_DEREFERENCE ? ACTION_FOLLOWLINKS : 0)
1168                                 | (opt & OPT_NORECURSION ? 0 : ACTION_RECURSE),
1169                                 tar_handle->accept,
1170                                 tar_handle->reject, zipMode);
1171         }
1172
1173         if (opt & OPT_ANY_COMPRESS) {
1174                 USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd);)
1175                 USE_FOR_NOMMU(const char *xformer_prog;)
1176
1177                 if (opt & OPT_COMPRESS)
1178                         USE_FOR_MMU(xformer = unpack_Z_stream;)
1179                         USE_FOR_NOMMU(xformer_prog = "uncompress";)
1180                 if (opt & OPT_GZIP)
1181                         USE_FOR_MMU(xformer = unpack_gz_stream;)
1182                         USE_FOR_NOMMU(xformer_prog = "gunzip";)
1183                 if (opt & OPT_BZIP2)
1184                         USE_FOR_MMU(xformer = unpack_bz2_stream;)
1185                         USE_FOR_NOMMU(xformer_prog = "bunzip2";)
1186                 if (opt & OPT_LZMA)
1187                         USE_FOR_MMU(xformer = unpack_lzma_stream;)
1188                         USE_FOR_NOMMU(xformer_prog = "unlzma";)
1189                 if (opt & OPT_XZ)
1190                         USE_FOR_MMU(xformer = unpack_xz_stream;)
1191                         USE_FOR_NOMMU(xformer_prog = "unxz";)
1192
1193                 open_transformer_with_sig(tar_handle->src_fd, xformer, xformer_prog);
1194                 /* Can't lseek over pipes */
1195                 tar_handle->seek = seek_by_read;
1196                 /*tar_handle->offset = 0; - already is */
1197         }
1198
1199         while (get_header_tar(tar_handle) == EXIT_SUCCESS)
1200                 continue;
1201
1202         /* Check that every file that should have been extracted was */
1203         while (tar_handle->accept) {
1204                 if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
1205                  && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
1206                 ) {
1207                         bb_error_msg_and_die("%s: not found in archive",
1208                                 tar_handle->accept->data);
1209                 }
1210                 tar_handle->accept = tar_handle->accept->link;
1211         }
1212         if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
1213                 close(tar_handle->src_fd);
1214
1215         if (SEAMLESS_COMPRESSION || OPT_COMPRESS) {
1216                 check_errors_in_children(0);
1217                 return bb_got_signal;
1218         }
1219         return EXIT_SUCCESS;
1220 }