| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini copy_file implementation for busybox |
| * |
| * Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu> |
| * SELinux support by Yuichi Nakamura <ynakam@hitachisoft.jp> |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| */ |
| #include "libbb.h" |
| |
| // FEATURE_NON_POSIX_CP: |
| // |
| // POSIX: if exists and -i, ask (w/o -i assume yes). |
| // Then open w/o EXCL (yes, not unlink!). |
| // If open still fails and -f, try unlink, then try open again. |
| // Result: a mess: |
| // If dest is a (sym)link, we overwrite link destination! |
| // (or fail, if it points to dir/nonexistent location/etc). |
| // This is strange, but POSIX-correct. |
| // coreutils cp has --remove-destination to override this... |
| |
| /* Called if open of destination, link creation etc fails. |
| * errno must be set to relevant value ("why we cannot create dest?") |
| * to give reasonable error message */ |
| static int ask_and_unlink(const char *dest, int flags) |
| { |
| int e = errno; |
| |
| #if !ENABLE_FEATURE_NON_POSIX_CP |
| if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) { |
| /* Either it exists, or the *path* doesnt exist */ |
| bb_perror_msg("can't create '%s'", dest); |
| return -1; |
| } |
| #endif |
| // else: act as if -f is always in effect. |
| // We don't want "can't create" msg, we want unlink to be done |
| // (silently unless -i). Why? POSIX cp usually succeeds with |
| // O_TRUNC open of existing file, and user is left ignorantly happy. |
| // With above block unconditionally enabled, non-POSIX cp |
| // will complain a lot more than POSIX one. |
| |
| /* TODO: maybe we should do it only if ctty is present? */ |
| if (flags & FILEUTILS_INTERACTIVE) { |
| // We would not do POSIX insanity. -i asks, |
| // then _unlinks_ the offender. Presto. |
| // (No "opening without O_EXCL", no "unlink only if -f") |
| // Or else we will end up having 3 open()s! |
| fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest); |
| if (!bb_ask_y_confirmation()) |
| return 0; /* not allowed to overwrite */ |
| } |
| if (unlink(dest) < 0) { |
| #if ENABLE_FEATURE_VERBOSE_CP_MESSAGE |
| if (e == errno && e == ENOENT) { |
| /* e == ENOTDIR is similar: path has non-dir component, |
| * but in this case we don't even reach copy_file() */ |
| bb_error_msg("can't create '%s': Path does not exist", dest); |
| return -1; /* error */ |
| } |
| #endif |
| errno = e; /* do not use errno from unlink */ |
| bb_perror_msg("can't create '%s'", dest); |
| return -1; /* error */ |
| } |
| #if ENABLE_FEATURE_CP_LONG_OPTIONS |
| if (flags & FILEUTILS_RMDEST) |
| if (flags & FILEUTILS_VERBOSE) |
| printf("removed '%s'\n", dest); |
| #endif |
| return 1; /* ok (to try again) */ |
| } |
| |
| /* Return: |
| * -1 error, copy not made |
| * 0 copy is made or user answered "no" in interactive mode |
| * (failures to preserve mode/owner/times are not reported in exit code) |
| */ |
| int FAST_FUNC copy_file(const char *source, const char *dest, int flags) |
| { |
| /* This is a recursive function, try to minimize stack usage */ |
| /* NB: each struct stat is ~100 bytes */ |
| struct stat source_stat; |
| struct stat dest_stat; |
| smallint retval = 0; |
| smallint dest_exists = 0; |
| smallint ovr; |
| |
| /* Inverse of cp -d ("cp without -d") */ |
| #define FLAGS_DEREF (flags & (FILEUTILS_DEREFERENCE + FILEUTILS_DEREFERENCE_L0)) |
| |
| if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) { |
| /* This may be a dangling symlink. |
| * Making [sym]links to dangling symlinks works, so... */ |
| if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) |
| goto make_links; |
| bb_perror_msg("can't stat '%s'", source); |
| return -1; |
| } |
| |
| if (lstat(dest, &dest_stat) < 0) { |
| if (errno != ENOENT) { |
| bb_perror_msg("can't stat '%s'", dest); |
| return -1; |
| } |
| } else { |
| if (source_stat.st_dev == dest_stat.st_dev |
| && source_stat.st_ino == dest_stat.st_ino |
| ) { |
| bb_error_msg("'%s' and '%s' are the same file", source, dest); |
| return -1; |
| } |
| if (flags & FILEUTILS_NO_OVERWRITE) /* cp -n */ |
| return 0; |
| dest_exists = 1; |
| } |
| |
| #if ENABLE_SELINUX |
| if ((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT) && is_selinux_enabled() > 0) { |
| security_context_t con; |
| if (lgetfilecon(source, &con) >= 0) { |
| if (setfscreatecon(con) < 0) { |
| bb_perror_msg("can't set setfscreatecon %s", con); |
| freecon(con); |
| return -1; |
| } |
| } else if (errno == ENOTSUP || errno == ENODATA) { |
| setfscreatecon_or_die(NULL); |
| } else { |
| bb_perror_msg("can't lgetfilecon %s", source); |
| return -1; |
| } |
| } |
| #endif |
| |
| if (S_ISDIR(source_stat.st_mode)) { |
| DIR *dp; |
| const char *tp; |
| struct dirent *d; |
| mode_t saved_umask = 0; |
| |
| if (!(flags & FILEUTILS_RECUR)) { |
| bb_error_msg("omitting directory '%s'", source); |
| return -1; |
| } |
| |
| /* Did we ever create source ourself before? */ |
| tp = is_in_ino_dev_hashtable(&source_stat); |
| if (tp) { |
| /* We did! it's a recursion! man the lifeboats... */ |
| bb_error_msg("recursion detected, omitting directory '%s'", |
| source); |
| return -1; |
| } |
| |
| if (dest_exists) { |
| if (!S_ISDIR(dest_stat.st_mode)) { |
| bb_error_msg("target '%s' is not a directory", dest); |
| return -1; |
| } |
| /* race here: user can substitute a symlink between |
| * this check and actual creation of files inside dest */ |
| } else { |
| /* Create DEST */ |
| mode_t mode; |
| saved_umask = umask(0); |
| |
| mode = source_stat.st_mode; |
| if (!(flags & FILEUTILS_PRESERVE_STATUS)) |
| mode = source_stat.st_mode & ~saved_umask; |
| /* Allow owner to access new dir (at least for now) */ |
| mode |= S_IRWXU; |
| if (mkdir(dest, mode) < 0) { |
| umask(saved_umask); |
| bb_perror_msg("can't create directory '%s'", dest); |
| return -1; |
| } |
| umask(saved_umask); |
| /* need stat info for add_to_ino_dev_hashtable */ |
| if (lstat(dest, &dest_stat) < 0) { |
| bb_perror_msg("can't stat '%s'", dest); |
| return -1; |
| } |
| } |
| /* remember (dev,inode) of each created dir. |
| * NULL: name is not remembered */ |
| add_to_ino_dev_hashtable(&dest_stat, NULL); |
| |
| /* Recursively copy files in SOURCE */ |
| dp = opendir(source); |
| if (dp == NULL) { |
| retval = -1; |
| goto preserve_mode_ugid_time; |
| } |
| |
| while ((d = readdir(dp)) != NULL) { |
| char *new_source, *new_dest; |
| |
| new_source = concat_subpath_file(source, d->d_name); |
| if (new_source == NULL) |
| continue; |
| new_dest = concat_path_file(dest, d->d_name); |
| if (copy_file(new_source, new_dest, flags & ~FILEUTILS_DEREFERENCE_L0) < 0) |
| retval = -1; |
| free(new_source); |
| free(new_dest); |
| } |
| closedir(dp); |
| |
| if (!dest_exists |
| && chmod(dest, source_stat.st_mode & ~saved_umask) < 0 |
| ) { |
| bb_perror_msg("can't preserve %s of '%s'", "permissions", dest); |
| /* retval = -1; - WRONG! copy *WAS* made */ |
| } |
| goto preserve_mode_ugid_time; |
| } |
| |
| if (dest_exists) { |
| if (flags & FILEUTILS_UPDATE) { |
| if (source_stat.st_mtime <= dest_stat.st_mtime) { |
| return 0; /* source file must be newer */ |
| } |
| } |
| #if ENABLE_FEATURE_CP_LONG_OPTIONS |
| if (flags & FILEUTILS_RMDEST) { |
| ovr = ask_and_unlink(dest, flags); |
| if (ovr <= 0) |
| return ovr; |
| dest_exists = 0; |
| } |
| #endif |
| } |
| |
| if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) { |
| int (*lf)(const char *oldpath, const char *newpath); |
| make_links: |
| /* Hmm... maybe |
| * if (DEREF && MAKE_SOFTLINK) source = realpath(source) ? |
| * (but realpath returns NULL on dangling symlinks...) */ |
| lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link; |
| if (lf(source, dest) < 0) { |
| ovr = ask_and_unlink(dest, flags); |
| if (ovr <= 0) |
| return ovr; |
| if (lf(source, dest) < 0) { |
| bb_perror_msg("can't create link '%s'", dest); |
| return -1; |
| } |
| } |
| /* _Not_ jumping to preserve_mode_ugid_time: |
| * (sym)links don't have those */ |
| return 0; |
| } |
| |
| if (/* "cp thing1 thing2" without -R: just open and read() from thing1 */ |
| !(flags & FILEUTILS_RECUR) |
| /* "cp [-opts] regular_file thing2" */ |
| || S_ISREG(source_stat.st_mode) |
| /* DEREF uses stat, which never returns S_ISLNK() == true. |
| * So the below is never true: */ |
| /* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */ |
| ) { |
| int src_fd; |
| int dst_fd; |
| mode_t new_mode; |
| |
| if (!FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) { |
| /* "cp -d symlink dst": create a link */ |
| goto dont_cat; |
| } |
| |
| if (ENABLE_FEATURE_PRESERVE_HARDLINKS && !FLAGS_DEREF) { |
| const char *link_target; |
| link_target = is_in_ino_dev_hashtable(&source_stat); |
| if (link_target) { |
| if (link(link_target, dest) < 0) { |
| ovr = ask_and_unlink(dest, flags); |
| if (ovr <= 0) |
| return ovr; |
| if (link(link_target, dest) < 0) { |
| bb_perror_msg("can't create link '%s'", dest); |
| return -1; |
| } |
| } |
| return 0; |
| } |
| add_to_ino_dev_hashtable(&source_stat, dest); |
| } |
| |
| src_fd = open_or_warn(source, O_RDONLY); |
| if (src_fd < 0) |
| return -1; |
| |
| /* Do not try to open with weird mode fields */ |
| new_mode = source_stat.st_mode; |
| if (!S_ISREG(source_stat.st_mode)) |
| new_mode = 0666; |
| |
| if (ENABLE_FEATURE_NON_POSIX_CP || (flags & FILEUTILS_INTERACTIVE)) { |
| /* |
| * O_CREAT|O_EXCL: require that file did not exist before creation |
| */ |
| dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode); |
| } else { /* POSIX, and not "cp -i" */ |
| /* |
| * O_CREAT|O_TRUNC: create, or truncate (security problem versus (sym)link attacks) |
| */ |
| dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode); |
| } |
| if (dst_fd == -1) { |
| ovr = ask_and_unlink(dest, flags); |
| if (ovr <= 0) { |
| close(src_fd); |
| return ovr; |
| } |
| /* It shouldn't exist. If it exists, do not open (symlink attack?) */ |
| dst_fd = open3_or_warn(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode); |
| if (dst_fd < 0) { |
| close(src_fd); |
| return -1; |
| } |
| } |
| |
| #if ENABLE_SELINUX |
| if ((flags & (FILEUTILS_PRESERVE_SECURITY_CONTEXT|FILEUTILS_SET_SECURITY_CONTEXT)) |
| && is_selinux_enabled() > 0 |
| ) { |
| security_context_t con; |
| if (getfscreatecon(&con) == -1) { |
| bb_simple_perror_msg("getfscreatecon"); |
| return -1; |
| } |
| if (con) { |
| if (setfilecon(dest, con) == -1) { |
| bb_perror_msg("setfilecon:%s,%s", dest, con); |
| freecon(con); |
| return -1; |
| } |
| freecon(con); |
| } |
| } |
| #endif |
| #if ENABLE_FEATURE_CP_REFLINK |
| # undef BTRFS_IOCTL_MAGIC |
| # define BTRFS_IOCTL_MAGIC 0x94 |
| # undef BTRFS_IOC_CLONE |
| # define BTRFS_IOC_CLONE _IOW (BTRFS_IOCTL_MAGIC, 9, int) |
| if (flags & FILEUTILS_REFLINK) { |
| retval = ioctl(dst_fd, BTRFS_IOC_CLONE, src_fd); |
| if (retval == 0) |
| goto do_close; |
| /* reflink did not work */ |
| if (flags & FILEUTILS_REFLINK_ALWAYS) { |
| bb_perror_msg("failed to clone '%s' from '%s'", dest, source); |
| goto do_close; |
| } |
| /* fall through to standard copy */ |
| retval = 0; |
| } |
| #endif |
| if (bb_copyfd_eof(src_fd, dst_fd) == -1) |
| retval = -1; |
| IF_FEATURE_CP_REFLINK(do_close:) |
| /* Careful with writing... */ |
| if (close(dst_fd) < 0) { |
| bb_perror_msg("error writing to '%s'", dest); |
| retval = -1; |
| } |
| /* ...but read size is already checked by bb_copyfd_eof */ |
| close(src_fd); |
| /* "cp /dev/something new_file" should not |
| * copy mode of /dev/something */ |
| if (!S_ISREG(source_stat.st_mode)) |
| return retval; |
| goto preserve_mode_ugid_time; |
| } |
| dont_cat: |
| |
| /* Source is a symlink or a special file */ |
| /* We are lazy here, a bit lax with races... */ |
| if (dest_exists) { |
| errno = EEXIST; |
| ovr = ask_and_unlink(dest, flags); |
| if (ovr <= 0) |
| return ovr; |
| } |
| if (S_ISLNK(source_stat.st_mode)) { |
| char *lpath = xmalloc_readlink_or_warn(source); |
| if (lpath) { |
| int r = symlink(lpath, dest); |
| if (r < 0) { |
| /* shared message */ |
| bb_perror_msg("can't create %slink '%s' to '%s'", |
| "sym", dest, lpath |
| ); |
| free(lpath); |
| return -1; |
| } |
| free(lpath); |
| if (flags & FILEUTILS_PRESERVE_STATUS) |
| if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0) |
| bb_perror_msg("can't preserve %s of '%s'", "ownership", dest); |
| } |
| /* _Not_ jumping to preserve_mode_ugid_time: |
| * symlinks don't have those */ |
| goto verb_and_exit; |
| } |
| if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) |
| || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) |
| ) { |
| if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) { |
| bb_perror_msg("can't create '%s'", dest); |
| return -1; |
| } |
| } else { |
| bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode); |
| return -1; |
| } |
| |
| preserve_mode_ugid_time: |
| |
| if (flags & FILEUTILS_PRESERVE_STATUS |
| /* Cannot happen: */ |
| /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */ |
| ) { |
| struct timeval times[2]; |
| |
| times[1].tv_sec = times[0].tv_sec = source_stat.st_mtime; |
| times[1].tv_usec = times[0].tv_usec = 0; |
| /* BTW, utimes sets usec-precision time - just FYI */ |
| if (utimes(dest, times) < 0) |
| bb_perror_msg("can't preserve %s of '%s'", "times", dest); |
| if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) { |
| source_stat.st_mode &= ~(S_ISUID | S_ISGID); |
| bb_perror_msg("can't preserve %s of '%s'", "ownership", dest); |
| } |
| if (chmod(dest, source_stat.st_mode) < 0) |
| bb_perror_msg("can't preserve %s of '%s'", "permissions", dest); |
| } |
| |
| verb_and_exit: |
| if (flags & FILEUTILS_VERBOSE) { |
| printf("'%s' -> '%s'\n", source, dest); |
| } |
| |
| return retval; |
| } |