source: MondoRescue/branches/2.2.9/mindi-busybox/archival/libarchive/data_extract_all.c@ 2725

/* vi: set sw=4 ts=4: */
/*
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"
#include "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;

#if ENABLE_FEATURE_TAR_SELINUX
    char *sctx = archive_handle->tar__next_file_sctx;
    if (!sctx)
        sctx = archive_handle->tar__global_sctx;
    if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
        setfscreatecon(sctx);
        free(archive_handle->tar__next_file_sctx);
        archive_handle->tar__next_file_sctx = NULL;
    }
#endif

    if (archive_handle->ah_flags & ARCHIVE_CREATE_LEADING_DIRS) {
        char *slash = strrchr(file_header->name, '/');
        if (slash) {
            *slash = '\0';
            bb_make_directory(file_header->name, -1, FILEUTILS_RECUR);
            *slash = '/';
        }
    }

    if (archive_handle->ah_flags & ARCHIVE_UNLINK_OLD) {
        /* Remove the entry if it exists */
        if (!S_ISDIR(file_header->mode)) {
            /* Is it hardlink?
             * We encode hard links as regular files of size 0 with a symlink */
            if (S_ISREG(file_header->mode)
             && file_header->link_target
             && file_header->size == 0
            ) {
                /* Ugly special case:
                 * tar cf t.tar hardlink1 hardlink2 hardlink1
                 * results in this tarball structure:
                 * hardlink1
                 * hardlink2 -> hardlink1
                 * hardlink1 -> hardlink1 <== !!!
                 */
                if (strcmp(file_header->link_target, file_header->name) == 0)
                    goto ret;
            }
            /* Proceed with deleting */
            if (unlink(file_header->name) == -1
             && errno != ENOENT
            ) {
                bb_perror_msg_and_die("can't remove old file %s",
                        file_header->name);
            }
        }
    }
    else if (archive_handle->ah_flags & ARCHIVE_EXTRACT_NEWER) {
        /* Remove the existing entry if its older than the extracted entry */
        struct stat existing_sb;
        if (lstat(file_header->name, &existing_sb) == -1) {
            if (errno != ENOENT) {
                bb_perror_msg_and_die("can't stat old file");
            }
        }
        else if (existing_sb.st_mtime >= file_header->mtime) {
            if (!(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
             && !S_ISDIR(file_header->mode)
            ) {
                bb_error_msg("%s not created: newer or "
                    "same age file exists", file_header->name);
            }
            data_skip(archive_handle);
            goto ret;
        }
        else if ((unlink(file_header->name) == -1) && (errno != EISDIR)) {
            bb_perror_msg_and_die("can't remove old file %s",
                    file_header->name);
        }
    }

    /* Handle hard links separately
     * We encode hard links as regular files of size 0 with a symlink */
    if (S_ISREG(file_header->mode)
     && file_header->link_target
     && file_header->size == 0
    ) {
        /* hard link */
        res = link(file_header->link_target, file_header->name);
        if ((res == -1) && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
            bb_perror_msg("can't create %slink "
                    "from %s to %s", "hard",
                    file_header->name,
                    file_header->link_target);
        }
        /* Hardlinks have no separate mode/ownership, skip chown/chmod */
        goto ret;
    }

    /* Create the filesystem entry */
    switch (file_header->mode & S_IFMT) {
    case S_IFREG: {
        /* Regular file */
        int flags = O_WRONLY | O_CREAT | O_EXCL;
        if (archive_handle->ah_flags & ARCHIVE_O_TRUNC)
            flags = O_WRONLY | O_CREAT | O_TRUNC;
        dst_fd = xopen3(file_header->name,
            flags,
            file_header->mode
            );
        bb_copyfd_exact_size(archive_handle->src_fd, dst_fd, file_header->size);
        close(dst_fd);
        break;
    }
    case S_IFDIR:
        res = mkdir(file_header->name, file_header->mode);
        if ((res == -1)
         && (errno != EISDIR) /* btw, Linux doesn't return this */
         && (errno != EEXIST)
         && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
        ) {
            bb_perror_msg("can't make dir %s", file_header->name);
        }
        break;
    case S_IFLNK:
        /* Symlink */
//TODO: what if file_header->link_target == NULL (say, corrupted tarball?)
        res = symlink(file_header->link_target, file_header->name);
        if ((res == -1)
         && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
        ) {
            bb_perror_msg("can't create %slink "
                "from %s to %s", "sym",
                file_header->name,
                file_header->link_target);
        }
        break;
    case S_IFSOCK:
    case S_IFBLK:
    case S_IFCHR:
    case S_IFIFO:
        res = mknod(file_header->name, file_header->mode, file_header->device);
        if ((res == -1)
         && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
        ) {
            bb_perror_msg("can't create node %s", file_header->name);
        }
        break;
    default:
        bb_error_msg_and_die("unrecognized file type");
    }

    if (!S_ISLNK(file_header->mode)) {
        if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_OWNER)) {
            uid_t uid = file_header->uid;
            gid_t gid = file_header->gid;
#if ENABLE_FEATURE_TAR_UNAME_GNAME
            if (!(archive_handle->ah_flags & ARCHIVE_NUMERIC_OWNER)) {
                if (file_header->tar__uname) {
//TODO: cache last name/id pair?
                    struct passwd *pwd = getpwnam(file_header->tar__uname);
                    if (pwd) uid = pwd->pw_uid;
                }
                if (file_header->tar__gname) {
                    struct group *grp = getgrnam(file_header->tar__gname);
                    if (grp) gid = grp->gr_gid;
                }
            }
#endif
            /* GNU tar 1.15.1 uses chown, not lchown */
            chown(file_header->name, uid, gid);
        }
        /* uclibc has no lchmod, glibc is even stranger -
         * it has lchmod which seems to do nothing!
         * so we use chmod... */
        if (!(archive_handle->ah_flags & ARCHIVE_DONT_RESTORE_PERM)) {
            chmod(file_header->name, file_header->mode);
        }
        if (archive_handle->ah_flags & ARCHIVE_RESTORE_DATE) {
            struct timeval t[2];

            t[1].tv_sec = t[0].tv_sec = file_header->mtime;
            t[1].tv_usec = t[0].tv_usec = 0;
            utimes(file_header->name, t);
        }
    }

 ret: ;
#if ENABLE_FEATURE_TAR_SELINUX
    if (sctx) {
        /* reset the context after creating an entry */
        setfscreatecon(NULL);
    }
#endif
}