source: MondoRescue/branches/stable/mindi-busybox/archival/tar.c@ 1770

/* vi: set sw=4 ts=4: */
/*
 * Mini tar implementation for busybox
 *
 * Modified to use common extraction code used by ar, cpio, dpkg-deb, dpkg
 *  Glenn McGrath <bug1@iinet.net.au>
 *
 * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
 * ground up.  It still has remnants of the old code lying about, but it is
 * very different now (i.e., cleaner, less global variables, etc.)
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Based in part in the tar implementation in sash
 *  Copyright (c) 1999 by David I. Bell
 *  Permission is granted to use, distribute, or modify this source,
 *  provided that this copyright notice remains intact.
 *  Permission to distribute sash derived code under the GPL has been granted.
 *
 * Based in part on the tar implementation from busybox-0.28
 *  Copyright (C) 1995 Bruce Perens
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <fnmatch.h>
#include <getopt.h>
#include "libbb.h"
#include "unarchive.h"

#define block_buf bb_common_bufsiz1

#if ENABLE_FEATURE_TAR_CREATE

/* Tar file constants  */

#define TAR_BLOCK_SIZE      512

/* POSIX tar Header Block, from POSIX 1003.1-1990  */
#define NAME_SIZE      100
#define NAME_SIZE_STR "100"
typedef struct TarHeader TarHeader;
struct TarHeader {        /* byte offset */
    char name[NAME_SIZE];     /*   0-99 */
    char mode[8];             /* 100-107 */
    char uid[8];              /* 108-115 */
    char gid[8];              /* 116-123 */
    char size[12];            /* 124-135 */
    char mtime[12];           /* 136-147 */
    char chksum[8];           /* 148-155 */
    char typeflag;            /* 156-156 */
    char linkname[NAME_SIZE]; /* 157-256 */
    char magic[6];            /* 257-262 */
    char version[2];          /* 263-264 */
    char uname[32];           /* 265-296 */
    char gname[32];           /* 297-328 */
    char devmajor[8];         /* 329-336 */
    char devminor[8];         /* 337-344 */
    char prefix[155];         /* 345-499 */
    char padding[12];         /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
};

/*
** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
** the only functions that deal with the HardLinkInfo structure.
** Even these functions use the xxxHardLinkInfo() functions.
*/
typedef struct HardLinkInfo HardLinkInfo;
struct HardLinkInfo {
    HardLinkInfo *next; /* Next entry in list */
    dev_t dev;          /* Device number */
    ino_t ino;          /* Inode number */
    short linkCount;    /* (Hard) Link Count */
    char name[1];       /* Start of filename (must be last) */
};

/* Some info to be carried along when creating a new tarball */
typedef struct TarBallInfo TarBallInfo;
struct TarBallInfo {
    int tarFd;              /* Open-for-write file descriptor
                               for the tarball */
    struct stat statBuf;    /* Stat info for the tarball, letting
                               us know the inode and device that the
                               tarball lives, so we can avoid trying
                               to include the tarball into itself */
    int verboseFlag;        /* Whether to print extra stuff or not */
    const llist_t *excludeList; /* List of files to not include */
    HardLinkInfo *hlInfoHead;   /* Hard Link Tracking Information */
    HardLinkInfo *hlInfo;   /* Hard Link Info for the current file */
};

/* A nice enum with all the possible tar file content types */
enum TarFileType {
    REGTYPE = '0',      /* regular file */
    REGTYPE0 = '\0',    /* regular file (ancient bug compat) */
    LNKTYPE = '1',      /* hard link */
    SYMTYPE = '2',      /* symbolic link */
    CHRTYPE = '3',      /* character special */
    BLKTYPE = '4',      /* block special */
    DIRTYPE = '5',      /* directory */
    FIFOTYPE = '6',     /* FIFO special */
    CONTTYPE = '7',     /* reserved */
    GNULONGLINK = 'K',  /* GNU long (>100 chars) link name */
    GNULONGNAME = 'L',  /* GNU long (>100 chars) file name */
};
typedef enum TarFileType TarFileType;

/* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
static void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
                    struct stat *statbuf,
                    const char *fileName)
{
    /* Note: hlInfoHeadPtr can never be NULL! */
    HardLinkInfo *hlInfo;

    hlInfo = xmalloc(sizeof(HardLinkInfo) + strlen(fileName));
    hlInfo->next = *hlInfoHeadPtr;
    *hlInfoHeadPtr = hlInfo;
    hlInfo->dev = statbuf->st_dev;
    hlInfo->ino = statbuf->st_ino;
    hlInfo->linkCount = statbuf->st_nlink;
    strcpy(hlInfo->name, fileName);
}

static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
{
    HardLinkInfo *hlInfo;
    HardLinkInfo *hlInfoNext;

    if (hlInfoHeadPtr) {
        hlInfo = *hlInfoHeadPtr;
        while (hlInfo) {
            hlInfoNext = hlInfo->next;
            free(hlInfo);
            hlInfo = hlInfoNext;
        }
        *hlInfoHeadPtr = NULL;
    }
}

/* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbuf)
{
    while (hlInfo) {
        if ((statbuf->st_ino == hlInfo->ino) && (statbuf->st_dev == hlInfo->dev))
            break;
        hlInfo = hlInfo->next;
    }
    return hlInfo;
}

/* Put an octal string into the specified buffer.
 * The number is zero padded and possibly null terminated.
 * Stores low-order bits only if whole value does not fit. */
static void putOctal(char *cp, int len, off_t value)
{
    char tempBuffer[sizeof(off_t)*3+1];
    char *tempString = tempBuffer;
    int width;

    width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
    tempString += (width - len);

    /* If string has leading zeroes, we can drop one */
    /* and field will have trailing '\0' */
    /* (increases chances of compat with other tars) */
    if (tempString[0] == '0')
        tempString++;

    /* Copy the string to the field */
    memcpy(cp, tempString, len);
}
#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))

static void chksum_and_xwrite(int fd, struct TarHeader* hp)
{
    /* POSIX says that checksum is done on unsigned bytes
     * (Sun and HP-UX gets it wrong... more details in
     * GNU tar source) */
    const unsigned char *cp;
    int chksum, size;

    strcpy(hp->magic, "ustar  ");

    /* Calculate and store the checksum (i.e., the sum of all of the bytes of
     * the header).  The checksum field must be filled with blanks for the
     * calculation.  The checksum field is formatted differently from the
     * other fields: it has 6 digits, a null, then a space -- rather than
     * digits, followed by a null like the other fields... */
    memset(hp->chksum, ' ', sizeof(hp->chksum));
    cp = (const unsigned char *) hp;
    chksum = 0;
    size = sizeof(*hp);
    do { chksum += *cp++; } while (--size);
    putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);

    /* Now write the header out to disk */
    xwrite(fd, hp, sizeof(*hp));
}

#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
static void writeLongname(int fd, int type, const char *name, int dir)
{
    static const struct {
        char mode[8];             /* 100-107 */
        char uid[8];              /* 108-115 */
        char gid[8];              /* 116-123 */
        char size[12];            /* 124-135 */
        char mtime[12];           /* 136-147 */
    } prefilled = {
        "0000000",
        "0000000",
        "0000000",
        "00000000000",
        "00000000000",
    };
    struct TarHeader header;
    int size;

    dir = !!dir; /* normalize: 0/1 */
    size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
    /* + dir: account for possible '/' */

    memset(&header, 0, sizeof(header));
    strcpy(header.name, "././@LongLink");
    memcpy(header.mode, prefilled.mode, sizeof(prefilled));
    PUT_OCTAL(header.size, size);
    header.typeflag = type;
    chksum_and_xwrite(fd, &header);

    /* Write filename[/] and pad the block. */
    /* dir=0: writes 'name<NUL>', pads */
    /* dir=1: writes 'name', writes '/<NUL>', pads */
    dir *= 2;
    xwrite(fd, name, size - dir);
    xwrite(fd, "/", dir);
    size = (-size) & (TAR_BLOCK_SIZE-1);
    memset(&header, 0, size);
    xwrite(fd, &header, size);
}
#endif

/* Write out a tar header for the specified file/directory/whatever */
void BUG_tar_header_size(void);
static int writeTarHeader(struct TarBallInfo *tbInfo,
        const char *header_name, const char *fileName, struct stat *statbuf)
{
    struct TarHeader header;

    if (sizeof(header) != 512)
        BUG_tar_header_size();

    memset(&header, 0, sizeof(struct TarHeader));

    strncpy(header.name, header_name, sizeof(header.name));

    /* POSIX says to mask mode with 07777. */
    PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
    PUT_OCTAL(header.uid, statbuf->st_uid);
    PUT_OCTAL(header.gid, statbuf->st_gid);
    memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
    PUT_OCTAL(header.mtime, statbuf->st_mtime);

    /* Enter the user and group names */
    safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
    safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));

    if (tbInfo->hlInfo) {
        /* This is a hard link */
        header.typeflag = LNKTYPE;
        strncpy(header.linkname, tbInfo->hlInfo->name,
                sizeof(header.linkname));
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
        /* Write out long linkname if needed */
        if (header.linkname[sizeof(header.linkname)-1])
            writeLongname(tbInfo->tarFd, GNULONGLINK,
                    tbInfo->hlInfo->name, 0);
#endif
    } else if (S_ISLNK(statbuf->st_mode)) {
        char *lpath = xmalloc_readlink_or_warn(fileName);
        if (!lpath)
            return FALSE;
        header.typeflag = SYMTYPE;
        strncpy(header.linkname, lpath, sizeof(header.linkname));
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
        /* Write out long linkname if needed */
        if (header.linkname[sizeof(header.linkname)-1])
            writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
#else
        /* If it is larger than 100 bytes, bail out */
        if (header.linkname[sizeof(header.linkname)-1]) {
            free(lpath);
            bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
            return FALSE;
        }
#endif
        free(lpath);
    } else if (S_ISDIR(statbuf->st_mode)) {
        header.typeflag = DIRTYPE;
        /* Append '/' only if there is a space for it */
        if (!header.name[sizeof(header.name)-1])
            header.name[strlen(header.name)] = '/';
    } else if (S_ISCHR(statbuf->st_mode)) {
        header.typeflag = CHRTYPE;
        PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
        PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
    } else if (S_ISBLK(statbuf->st_mode)) {
        header.typeflag = BLKTYPE;
        PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
        PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
    } else if (S_ISFIFO(statbuf->st_mode)) {
        header.typeflag = FIFOTYPE;
    } else if (S_ISREG(statbuf->st_mode)) {
        if (sizeof(statbuf->st_size) > 4
         && statbuf->st_size > (off_t)0777777777777LL
        ) {
            bb_error_msg_and_die("cannot store file '%s' "
                "of size %"OFF_FMT"d, aborting",
                fileName, statbuf->st_size);
        }
        header.typeflag = REGTYPE;
        PUT_OCTAL(header.size, statbuf->st_size);
    } else {
        bb_error_msg("%s: unknown file type", fileName);
        return FALSE;
    }

#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
    /* Write out long name if needed */
    /* (we, like GNU tar, output long linkname *before* long name) */
    if (header.name[sizeof(header.name)-1])
        writeLongname(tbInfo->tarFd, GNULONGNAME,
                header_name, S_ISDIR(statbuf->st_mode));
#endif

    /* Now write the header out to disk */
    chksum_and_xwrite(tbInfo->tarFd, &header);

    /* Now do the verbose thing (or not) */
    if (tbInfo->verboseFlag) {
        FILE *vbFd = stdout;

        if (tbInfo->tarFd == STDOUT_FILENO) /* If the archive goes to stdout, verbose to stderr */
            vbFd = stderr;
        /* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
        /* We don't have such excesses here: for us "v" == "vv" */
        /* '/' is probably a GNUism */
        fprintf(vbFd, "%s%s\n", header_name,
                S_ISDIR(statbuf->st_mode) ? "/" : "");
    }

    return TRUE;
}

#if ENABLE_FEATURE_TAR_FROM
static int exclude_file(const llist_t *excluded_files, const char *file)
{
    while (excluded_files) {
        if (excluded_files->data[0] == '/') {
            if (fnmatch(excluded_files->data, file,
                        FNM_PATHNAME | FNM_LEADING_DIR) == 0)
                return 1;
        } else {
            const char *p;

            for (p = file; p[0] != '\0'; p++) {
                if ((p == file || p[-1] == '/') && p[0] != '/' &&
                    fnmatch(excluded_files->data, p,
                            FNM_PATHNAME | FNM_LEADING_DIR) == 0)
                    return 1;
            }
        }
        excluded_files = excluded_files->link;
    }

    return 0;
}
#else
#define exclude_file(excluded_files, file) 0
#endif

static int writeFileToTarball(const char *fileName, struct stat *statbuf,
            void *userData, int depth ATTRIBUTE_UNUSED)
{
    struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
    const char *header_name;
    int inputFileFd = -1;

    /*
     * Check to see if we are dealing with a hard link.
     * If so -
     * Treat the first occurance of a given dev/inode as a file while
     * treating any additional occurances as hard links.  This is done
     * by adding the file information to the HardLinkInfo linked list.
     */
    tbInfo->hlInfo = NULL;
    if (statbuf->st_nlink > 1) {
        tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
        if (tbInfo->hlInfo == NULL)
            addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, fileName);
    }

    /* It is against the rules to archive a socket */
    if (S_ISSOCK(statbuf->st_mode)) {
        bb_error_msg("%s: socket ignored", fileName);
        return TRUE;
    }

    /* It is a bad idea to store the archive we are in the process of creating,
     * so check the device and inode to be sure that this particular file isn't
     * the new tarball */
    if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
        tbInfo->statBuf.st_ino == statbuf->st_ino) {
        bb_error_msg("%s: file is the archive; skipping", fileName);
        return TRUE;
    }

    header_name = fileName;
    while (header_name[0] == '/') {
        static smallint warned;

        if (!warned) {
            bb_error_msg("removing leading '/' from member names");
            warned = 1;
        }
        header_name++;
    }

#if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
    if (strlen(fileName) >= NAME_SIZE) {
        bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
        return TRUE;
    }
#endif

    if (header_name[0] == '\0')
        return TRUE;

    if (exclude_file(tbInfo->excludeList, header_name))
        return SKIP;

    /* Is this a regular file? */
    if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
        /* open the file we want to archive, and make sure all is well */
        inputFileFd = open_or_warn(fileName, O_RDONLY);
        if (inputFileFd < 0) {
            return FALSE;
        }
    }

    /* Add an entry to the tarball */
    if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
        return FALSE;
    }

    /* If it was a regular file, write out the body */
    if (inputFileFd >= 0) {
        size_t readSize;
        /* Write the file to the archive. */
        /* We record size into header first, */
        /* and then write out file. If file shrinks in between, */
        /* tar will be corrupted. So we don't allow for that. */
        /* NB: GNU tar 1.16 warns and pads with zeroes */
        /* or even seeks back and updates header */
        bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
        ////off_t readSize;
        ////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
        ////if (readSize != statbuf->st_size && readSize >= 0) {
        ////    bb_error_msg_and_die("short read from %s, aborting", fileName);
        ////}

        /* Check that file did not grow in between? */
        /* if (safe_read(inputFileFd, 1) == 1) warn but continue? */

        close(inputFileFd);

        /* Pad the file up to the tar block size */
        /* (a few tricks here in the name of code size) */
        readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
        memset(block_buf, 0, readSize);
        xwrite(tbInfo->tarFd, block_buf, readSize);
    }

    return TRUE;
}

static int writeTarFile(const int tar_fd, const int verboseFlag,
    const unsigned long dereferenceFlag, const llist_t *include,
    const llist_t *exclude, const int gzip)
{
    pid_t gzipPid = 0;
    int errorFlag = FALSE;
    struct TarBallInfo tbInfo;

    tbInfo.hlInfoHead = NULL;

    fchmod(tar_fd, 0644);
    tbInfo.tarFd = tar_fd;
    tbInfo.verboseFlag = verboseFlag;

    /* Store the stat info for the tarball's file, so
     * can avoid including the tarball into itself....  */
    if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
        bb_perror_msg_and_die("cannot stat tar file");

    if ((ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2) && gzip) {
        int gzipDataPipe[2] = { -1, -1 };
        int gzipStatusPipe[2] = { -1, -1 };
        volatile int vfork_exec_errno = 0;
        const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";

        xpipe(gzipDataPipe);
        xpipe(gzipStatusPipe);

        signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */

#if defined(__GNUC__) && __GNUC__
        /* Avoid vfork clobbering */
        (void) &include;
        (void) &errorFlag;
        (void) &zip_exec;
#endif

        gzipPid = vfork();

        if (gzipPid == 0) {
            dup2(gzipDataPipe[0], 0);
            close(gzipDataPipe[1]);

            dup2(tbInfo.tarFd, 1);

            close(gzipStatusPipe[0]);
            fcntl(gzipStatusPipe[1], F_SETFD, FD_CLOEXEC);  /* close on exec shows success */

            BB_EXECLP(zip_exec, zip_exec, "-f", NULL);
            vfork_exec_errno = errno;

            close(gzipStatusPipe[1]);
            exit(-1);
        } else if (gzipPid > 0) {
            close(gzipDataPipe[0]);
            close(gzipStatusPipe[1]);

            while (1) {
                char buf;

                int n = full_read(gzipStatusPipe[0], &buf, 1);

                if (n == 0 && vfork_exec_errno != 0) {
                    errno = vfork_exec_errno;
                    bb_perror_msg_and_die("cannot exec %s", zip_exec);
                } else if ((n < 0) && (errno == EAGAIN || errno == EINTR))
                    continue;   /* try it again */
                break;
            }
            close(gzipStatusPipe[0]);

            tbInfo.tarFd = gzipDataPipe[1];
        } else bb_perror_msg_and_die("vfork gzip");
    }

    tbInfo.excludeList = exclude;

    /* Read the directory/files and iterate over them one at a time */
    while (include) {
        if (!recursive_action(include->data, ACTION_RECURSE |
                (dereferenceFlag ? ACTION_FOLLOWLINKS : 0),
                writeFileToTarball, writeFileToTarball, &tbInfo, 0))
        {
            errorFlag = TRUE;
        }
        include = include->link;
    }
    /* Write two empty blocks to the end of the archive */
    memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
    xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);

    /* To be pedantically correct, we would check if the tarball
     * is smaller than 20 tar blocks, and pad it if it was smaller,
     * but that isn't necessary for GNU tar interoperability, and
     * so is considered a waste of space */

    /* Close so the child process (if any) will exit */
    close(tbInfo.tarFd);

    /* Hang up the tools, close up shop, head home */
    if (ENABLE_FEATURE_CLEAN_UP)
        freeHardLinkInfo(&tbInfo.hlInfoHead);

    if (errorFlag)
        bb_error_msg("error exit delayed from previous errors");

    if (gzipPid) {
        int status;
        if (waitpid(gzipPid, &status, 0) == -1)
            bb_perror_msg("waitpid");
        else if (!WIFEXITED(status) || WEXITSTATUS(status))
            /* gzip was killed or has exited with nonzero! */
            errorFlag = TRUE;
    }
    return errorFlag;
}
#else
int writeTarFile(const int tar_fd, const int verboseFlag,
    const unsigned long dereferenceFlag, const llist_t *include,
    const llist_t *exclude, const int gzip);
#endif /* FEATURE_TAR_CREATE */

#if ENABLE_FEATURE_TAR_FROM
static llist_t *append_file_list_to_list(llist_t *list)
{
    FILE *src_stream;
    llist_t *cur = list;
    llist_t *tmp;
    char *line;
    llist_t *newlist = NULL;

    while (cur) {
        src_stream = xfopen(cur->data, "r");
        tmp = cur;
        cur = cur->link;
        free(tmp);
        while ((line = xmalloc_getline(src_stream)) != NULL) {
            /* kill trailing '/' unless the string is just "/" */
            char *cp = last_char_is(line, '/');
            if (cp > line)
                *cp = '\0';
            llist_add_to(&newlist, line);
        }
        fclose(src_stream);
    }
    return newlist;
}
#else
#define append_file_list_to_list(x) 0
#endif

#if ENABLE_FEATURE_TAR_COMPRESS
static char get_header_tar_Z(archive_handle_t *archive_handle)
{
    /* Can't lseek over pipes */
    archive_handle->seek = seek_by_read;

    /* do the decompression, and cleanup */
    if (xread_char(archive_handle->src_fd) != 0x1f
     || xread_char(archive_handle->src_fd) != 0x9d
    ) {
        bb_error_msg_and_die("invalid magic");
    }

    archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress, "uncompress", "uncompress", "-cf", "-", NULL);
    archive_handle->offset = 0;
    while (get_header_tar(archive_handle) == EXIT_SUCCESS)
        /* nothing */;

    /* Can only do one file at a time */
    return EXIT_FAILURE;
}
#else
#define get_header_tar_Z NULL
#endif

#ifdef CHECK_FOR_CHILD_EXITCODE
/* Looks like it isn't needed - tar detects malformed (truncated)
 * archive if e.g. bunzip2 fails */
static int child_error;

static void handle_SIGCHLD(int status)
{
    /* Actually, 'status' is a signo. We reuse it for other needs */

    /* Wait for any child without blocking */
    if (waitpid(-1, &status, WNOHANG) < 0)
        /* wait failed?! I'm confused... */
        return;

    if (WIFEXITED(status) && WEXITSTATUS(status)==0)
        /* child exited with 0 */
        return;
    /* Cannot happen?
    if (!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
    child_error = 1;
}
#endif

enum {
    OPTBIT_KEEP_OLD = 7,
    USE_FEATURE_TAR_CREATE(  OPTBIT_CREATE      ,)
    USE_FEATURE_TAR_CREATE(  OPTBIT_DEREFERENCE ,)
    USE_FEATURE_TAR_BZIP2(   OPTBIT_BZIP2       ,)
    USE_FEATURE_TAR_LZMA(    OPTBIT_LZMA        ,)
    USE_FEATURE_TAR_FROM(    OPTBIT_INCLUDE_FROM,)
    USE_FEATURE_TAR_FROM(    OPTBIT_EXCLUDE_FROM,)
    USE_FEATURE_TAR_GZIP(    OPTBIT_GZIP        ,)
    USE_FEATURE_TAR_COMPRESS(OPTBIT_COMPRESS    ,)
    OPTBIT_NOPRESERVE_OWN,
    OPTBIT_NOPRESERVE_PERM,
    OPT_TEST         = 1 << 0, // t
    OPT_EXTRACT      = 1 << 1, // x
    OPT_BASEDIR      = 1 << 2, // C
    OPT_TARNAME      = 1 << 3, // f
    OPT_2STDOUT      = 1 << 4, // O
    OPT_P            = 1 << 5, // p
    OPT_VERBOSE      = 1 << 6, // v
    OPT_KEEP_OLD     = 1 << 7, // k
    OPT_CREATE       = USE_FEATURE_TAR_CREATE(  (1<<OPTBIT_CREATE      )) + 0, // c
    OPT_DEREFERENCE  = USE_FEATURE_TAR_CREATE(  (1<<OPTBIT_DEREFERENCE )) + 0, // h
    OPT_BZIP2        = USE_FEATURE_TAR_BZIP2(   (1<<OPTBIT_BZIP2       )) + 0, // j
    OPT_LZMA         = USE_FEATURE_TAR_LZMA(    (1<<OPTBIT_LZMA        )) + 0, // a
    OPT_INCLUDE_FROM = USE_FEATURE_TAR_FROM(    (1<<OPTBIT_INCLUDE_FROM)) + 0, // T
    OPT_EXCLUDE_FROM = USE_FEATURE_TAR_FROM(    (1<<OPTBIT_EXCLUDE_FROM)) + 0, // X
    OPT_GZIP         = USE_FEATURE_TAR_GZIP(    (1<<OPTBIT_GZIP        )) + 0, // z
    OPT_COMPRESS     = USE_FEATURE_TAR_COMPRESS((1<<OPTBIT_COMPRESS    )) + 0, // Z
    OPT_NOPRESERVE_OWN  = 1 << OPTBIT_NOPRESERVE_OWN , // no-same-owner
    OPT_NOPRESERVE_PERM = 1 << OPTBIT_NOPRESERVE_PERM, // no-same-permissions
};
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
static const char tar_longopts[] ALIGN1 =
    "list\0"                No_argument       "t"
    "extract\0"             No_argument       "x"
    "directory\0"           Required_argument "C"
    "file\0"                Required_argument "f"
    "to-stdout\0"           No_argument       "O"
    "same-permissions\0"    No_argument       "p"
    "verbose\0"             No_argument       "v"
    "keep-old\0"            No_argument       "k"
# if ENABLE_FEATURE_TAR_CREATE
    "create\0"              No_argument       "c"
    "dereference\0"         No_argument       "h"
# endif
# if ENABLE_FEATURE_TAR_BZIP2
    "bzip2\0"               No_argument       "j"
# endif
# if ENABLE_FEATURE_TAR_LZMA
    "lzma\0"                No_argument       "a"
# endif
# if ENABLE_FEATURE_TAR_FROM
    "files-from\0"          Required_argument "T"
    "exclude-from\0"        Required_argument "X"
# endif
# if ENABLE_FEATURE_TAR_GZIP
    "gzip\0"                No_argument       "z"
# endif
# if ENABLE_FEATURE_TAR_COMPRESS
    "compress\0"            No_argument       "Z"
# endif
    "no-same-owner\0"       No_argument       "\xfd"
    "no-same-permissions\0" No_argument       "\xfe"
    /* --exclude takes next bit position in option mask, */
    /* therefore we have to either put it _after_ --no-same-perm */
    /* or add OPT[BIT]_EXCLUDE before OPT[BIT]_NOPRESERVE_OWN */
# if ENABLE_FEATURE_TAR_FROM
    "exclude\0"             Required_argument "\xff"
# endif
    ;
#endif

int tar_main(int argc, char **argv);
int tar_main(int argc, char **argv)
{
    char (*get_header_ptr)(archive_handle_t *) = get_header_tar;
    archive_handle_t *tar_handle;
    char *base_dir = NULL;
    const char *tar_filename = "-";
    unsigned opt;
    int verboseFlag = 0;
#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
    llist_t *excludes = NULL;
#endif

    /* Initialise default values */
    tar_handle = init_handle();
    tar_handle->flags = ARCHIVE_CREATE_LEADING_DIRS
                      | ARCHIVE_PRESERVE_DATE
                      | ARCHIVE_EXTRACT_UNCONDITIONAL;

    /* Prepend '-' to the first argument if required */
    opt_complementary = "--:" // first arg is options
        "tt:vv:" // count -t,-v
        "?:" // bail out with usage instead of error return
        "X::T::" // cumulative lists
#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
        "\xff::" // cumulative lists for --exclude
#endif
        USE_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
        USE_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
        SKIP_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
    applet_long_options = tar_longopts;
#endif
    opt = getopt32(argv,
        "txC:f:Opvk"
        USE_FEATURE_TAR_CREATE(  "ch"  )
        USE_FEATURE_TAR_BZIP2(   "j"   )
        USE_FEATURE_TAR_LZMA(    "a"   )
        USE_FEATURE_TAR_FROM(    "T:X:")
        USE_FEATURE_TAR_GZIP(    "z"   )
        USE_FEATURE_TAR_COMPRESS("Z"   )
        , &base_dir // -C dir
        , &tar_filename // -f filename
        USE_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
        USE_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
        , &excludes // --exclude
#endif
        , &verboseFlag // combined count for -t and -v
        , &verboseFlag // combined count for -t and -v
        );

    if (verboseFlag) tar_handle->action_header = header_verbose_list;
    if (verboseFlag == 1) tar_handle->action_header = header_list;

    if (opt & OPT_EXTRACT)
        tar_handle->action_data = data_extract_all;

    if (opt & OPT_2STDOUT)
        tar_handle->action_data = data_extract_to_stdout;

    if (opt & OPT_KEEP_OLD)
        tar_handle->flags &= ~ARCHIVE_EXTRACT_UNCONDITIONAL;

    if (opt & OPT_NOPRESERVE_OWN)
        tar_handle->flags |= ARCHIVE_NOPRESERVE_OWN;

    if (opt & OPT_NOPRESERVE_PERM)
        tar_handle->flags |= ARCHIVE_NOPRESERVE_PERM;

    if (opt & OPT_GZIP)
        get_header_ptr = get_header_tar_gz;

    if (opt & OPT_BZIP2)
        get_header_ptr = get_header_tar_bz2;

    if (opt & OPT_LZMA)
        get_header_ptr = get_header_tar_lzma;

    if (opt & OPT_COMPRESS)
        get_header_ptr = get_header_tar_Z;

#if ENABLE_FEATURE_TAR_FROM
    tar_handle->reject = append_file_list_to_list(tar_handle->reject);
#if ENABLE_FEATURE_TAR_LONG_OPTIONS
    /* Append excludes to reject */
    while (excludes) {
        llist_t *next = excludes->link;
        excludes->link = tar_handle->reject;
        tar_handle->reject = excludes;
        excludes = next;
    }
#endif
    tar_handle->accept = append_file_list_to_list(tar_handle->accept);
#endif

    /* Check if we are reading from stdin */
    if (argv[optind] && *argv[optind] == '-') {
        /* Default is to read from stdin, so just skip to next arg */
        optind++;
    }

    /* Setup an array of filenames to work with */
    /* TODO: This is the same as in ar, separate function ? */
    while (optind < argc) {
        /* kill trailing '/' unless the string is just "/" */
        char *cp = last_char_is(argv[optind], '/');
        if (cp > argv[optind])
            *cp = '\0';
        llist_add_to_end(&tar_handle->accept, argv[optind]);
        optind++;
    }

    if (tar_handle->accept || tar_handle->reject)
        tar_handle->filter = filter_accept_reject_list;

    /* Open the tar file */
    {
        FILE *tar_stream;
        int flags;

        if (opt & OPT_CREATE) {
            /* Make sure there is at least one file to tar up.  */
            if (tar_handle->accept == NULL)
                bb_error_msg_and_die("empty archive");

            tar_stream = stdout;
            /* Mimicking GNU tar 1.15.1: */
            flags = O_WRONLY|O_CREAT|O_TRUNC;
        /* was doing unlink; open(O_WRONLY|O_CREAT|O_EXCL); why? */
        } else {
            tar_stream = stdin;
            flags = O_RDONLY;
        }

        if (LONE_DASH(tar_filename)) {
            tar_handle->src_fd = fileno(tar_stream);
            tar_handle->seek = seek_by_read;
        } else {
            tar_handle->src_fd = xopen(tar_filename, flags);
        }
    }

    if (base_dir)
        xchdir(base_dir);

#ifdef CHECK_FOR_CHILD_EXITCODE
    /* We need to know whether child (gzip/bzip/etc) exits abnormally */
    signal(SIGCHLD, handle_SIGCHLD);
#endif

    /* create an archive */
    if (opt & OPT_CREATE) {
        int zipMode = 0;
        if (ENABLE_FEATURE_TAR_GZIP && get_header_ptr == get_header_tar_gz)
            zipMode = 1;
        if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
            zipMode = 2;
        /* NB: writeTarFile() closes tar_handle->src_fd */
        return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
                tar_handle->accept,
                tar_handle->reject, zipMode);
    }

    while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
        /* nothing */;

    /* Check that every file that should have been extracted was */
    while (tar_handle->accept) {
        if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
         && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
        ) {
            bb_error_msg_and_die("%s: not found in archive",
                tar_handle->accept->data);
        }
        tar_handle->accept = tar_handle->accept->link;
    }
    if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
        close(tar_handle->src_fd);

    return EXIT_SUCCESS;
}