busybox

/* vi: set sw=4 ts=4: */

/*

 * Licensed under GPLv2 or later, see file LICENSE in this source tree.

 */

​

#include "libbb.h"

#include "bb_archive.h"

​

void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)

{

    file_header_t *file_header = archive_handle->file_header;

    int dst_fd;

    int res;

    char *hard_link;

#if ENABLE_FEATURE_TAR_LONG_OPTIONS

    char *dst_name;

#else

# define dst_name (file_header->name)

#endif

​

#if ENABLE_FEATURE_TAR_SELINUX

    char *sctx = archive_handle->tar__sctx[PAX_NEXT_FILE];

    if (!sctx)

        sctx = archive_handle->tar__sctx[PAX_GLOBAL];

    if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */

        setfscreatecon(sctx);

        free(archive_handle->tar__sctx[PAX_NEXT_FILE]);

        archive_handle->tar__sctx[PAX_NEXT_FILE] = NULL;

    }

#endif

​

    /* Hard links are encoded as regular files of size 0

     * with a nonempty link field */

    hard_link = NULL;

    if (S_ISREG(file_header->mode) && file_header->size == 0)

        hard_link = file_header->link_target;

​

#if ENABLE_FEATURE_TAR_LONG_OPTIONS

    dst_name = file_header->name;

    if (archive_handle->tar__strip_components) {

        unsigned n = archive_handle->tar__strip_components;

        do {

            dst_name = strchr(dst_name, '/');

            if (!dst_name || dst_name[1] == '\0') {

                data_skip(archive_handle);

                goto ret;

            }

            dst_name++;

            /*

             * Link target is shortened only for hardlinks:

             * softlinks restored unchanged.

             */

            if (hard_link) {

// GNU tar 1.26 does not check that we reached end of link name:

// if "dir/hardlink" is hardlinked to "file",

// tar xvf a.tar --strip-components=1 says:

//  tar: hardlink: Cannot hard link to '': No such file or directory

// and continues processing. We silently skip such entries.

                hard_link = strchr(hard_link, '/');

                if (!hard_link || hard_link[1] == '\0') {

                    data_skip(archive_handle);

                    goto ret;

                }