// (or fail, if it points to dir/nonexistent location/etc).
// This is strange, but POSIX-correct.
// coreutils cp has --remove-destination to override this...
+//
+// NB: we have special code which still allows for "cp file /dev/node"
+// to work POSIX-ly (the only realistic case where it makes sense)
#define DO_POSIX_CP 0 /* 1 - POSIX behavior, 0 - safe behavior */
-
+// errno must be set to relevant value ("why we cannot create dest?")
+// for POSIX mode to give reasonable error message
static int ask_and_unlink(const char *dest, int flags)
{
- // If !DO_POSIX_CP, act as if -f is always in effect - we don't want
- // "'file' exists" msg, we want unlink to be done (silently unless -i
- // is also in effect).
- // This prevents safe way from asking more questions than POSIX does.
+ int e = errno;
#if DO_POSIX_CP
if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) {
- fprintf(stderr, "'%s' exists\n", dest);
+ // Either it exists, or the *path* doesnt exist
+ bb_perror_msg("cannot create '%s'", dest);
return -1;
}
#endif
+ // If !DO_POSIX_CP, act as if -f is always in effect - we don't want
+ // "cannot create" msg, we want unlink to be done (silently unless -i).
// 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 unlinks only if -f)
+ // (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_confirmation())
return 0; // not allowed to overwrite
}
if (unlink(dest) < 0) {
- bb_perror_msg("cannot remove '%s'", dest);
+#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("cannot create '%s': Path does not exist", dest);
+ return -1; // error
+ }
+#endif
+ errno = e;
+ bb_perror_msg("cannot create '%s'", dest);
return -1; // error
}
return 1; // ok (to try again)
* 0 copy is made or user answered "no" in interactive mode
* (failures to preserve mode/owner/times are not reported in exit code)
*/
-int copy_file(const char *source, const char *dest, int flags)
+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;
- int status = 0;
+ signed char retval = 0;
signed char dest_exists = 0;
signed char ovr;
+/* Inverse of cp -d ("cp without -d") */
#define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE)
if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) {
if (S_ISDIR(source_stat.st_mode)) {
DIR *dp;
+ const char *tp;
struct dirent *d;
mode_t saved_umask = 0;
return -1;
}
- /* Create DEST. */
+ /* 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;
+ }
+
+ /* Create DEST */
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 {
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("cannot 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("cannot 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. */
+ /* Recursively copy files in SOURCE */
dp = opendir(source);
if (dp == NULL) {
- status = -1;
- goto preserve_status;
+ retval = -1;
+ goto preserve_mode_ugid_time;
}
while ((d = readdir(dp)) != NULL) {
continue;
new_dest = concat_path_file(dest, d->d_name);
if (copy_file(new_source, new_dest, flags) < 0)
- status = -1;
+ retval = -1;
free(new_source);
free(new_dest);
}
if (!dest_exists
&& chmod(dest, source_stat.st_mode & ~saved_umask) < 0
) {
- bb_perror_msg("cannot change permissions of '%s'", dest);
- status = -1;
+ bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
+ /* retval = -1; - WRONG! copy *WAS* made */
}
+ goto preserve_mode_ugid_time;
+ }
- } else if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
+ if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
int (*lf)(const char *oldpath, const char *newpath);
make_links:
// Hmm... maybe
return -1;
}
}
+ /* _Not_ jumping to preserve_mode_ugid_time:
+ * hard/softlinks don't have those */
return 0;
+ }
- } else if (S_ISREG(source_stat.st_mode)
- /* Huh? DEREF uses stat, which never returns links! */
+ 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;
- if (ENABLE_FEATURE_PRESERVE_HARDLINKS) {
- char *link_name;
-
- if (!FLAGS_DEREF) {
- link_name = is_in_ino_dev_hashtable(&source_stat);
- if (link_name) {
- if (link(link_name, dest) < 0) {
- ovr = ask_and_unlink(dest, flags);
- if (ovr <= 0)
- return ovr;
- if (link(link_name, dest) < 0) {
- bb_perror_msg("cannot create link '%s'", dest);
- return -1;
- }
+ 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("cannot create link '%s'", dest);
+ return -1;
}
- return 0;
}
+ return 0;
}
add_to_ino_dev_hashtable(&source_stat, dest);
}
src_fd = open_or_warn(source, O_RDONLY);
- if (src_fd < 0) {
+ if (src_fd < 0)
return -1;
- }
-#if DO_POSIX_CP /* POSIX way (a security problem versus symlink attacks!): */
- dst_fd = open(dest, (flags & FILEUTILS_INTERACTIVE)
- ? O_WRONLY|O_CREAT|O_EXCL
- : O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode);
-#else /* safe way: */
- dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, source_stat.st_mode);
-#endif
+ /* 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;
+
+ /* POSIX way is a security problem versus symlink attacks,
+ * we do it only for non-symlinks, and only for non-recursive,
+ * non-interactive cp. NB: it is still racy
+ * for "cp file /home/bad_user/file" case
+ * (user can rm file and create a link to /etc/passwd) */
+ if (DO_POSIX_CP
+ || (dest_exists
+ && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE))
+ && !S_ISLNK(dest_stat.st_mode))
+ ) {
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode);
+ } else /* safe way: */
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode);
if (dst_fd == -1) {
ovr = ask_and_unlink(dest, flags);
if (ovr <= 0) {
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, source_stat.st_mode);
+ 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)
- || (flags & FILEUTILS_SET_SECURITY_CONTEXT))
+ if ((flags & (FILEUTILS_PRESERVE_SECURITY_CONTEXT|FILEUTILS_SET_SECURITY_CONTEXT))
&& is_selinux_enabled() > 0
) {
security_context_t con;
}
#endif
if (bb_copyfd_eof(src_fd, dst_fd) == -1)
- status = -1;
+ retval = -1;
+ /* Ok, writing side I can understand... */
if (close(dst_fd) < 0) {
bb_perror_msg("cannot close '%s'", dest);
- status = -1;
- }
- if (close(src_fd) < 0) {
- bb_perror_msg("cannot close '%s'", source);
- status = -1;
+ retval = -1;
}
-
- } else 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)
- || S_ISLNK(source_stat.st_mode)
- ) {
- // We are lazy here, a bit lax with races...
- if (dest_exists) {
- ovr = ask_and_unlink(dest, flags);
- if (ovr <= 0)
- return ovr;
- }
- if (S_ISFIFO(source_stat.st_mode)) {
- if (mkfifo(dest, source_stat.st_mode) < 0) {
- bb_perror_msg("cannot create fifo '%s'", dest);
- return -1;
- }
- } else if (S_ISLNK(source_stat.st_mode)) {
- char *lpath;
-
- lpath = xmalloc_readlink_or_warn(source);
- if (lpath && symlink(lpath, dest) < 0) {
+ /* ...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);
+ free(lpath);
+ if (r < 0) {
bb_perror_msg("cannot create symlink '%s'", dest);
- 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("cannot preserve %s of '%s'", "ownership", dest);
-
- return 0;
-
- } else {
- if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
- bb_perror_msg("cannot create '%s'", dest);
- return -1;
- }
+ }
+ /* _Not_ jumping to preserve_mode_ugid_time:
+ * symlinks don't have those */
+ return 0;
+ }
+ 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("cannot create '%s'", dest);
+ return -1;
}
} else {
- bb_error_msg("internal error: unrecognized file type");
+ bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode);
return -1;
}
- preserve_status:
+ preserve_mode_ugid_time:
if (flags & FILEUTILS_PRESERVE_STATUS
/* Cannot happen: */
times.actime = source_stat.st_atime;
times.modtime = source_stat.st_mtime;
+ /* BTW, utimes sets usec-precision time - just FYI */
if (utime(dest, ×) < 0)
bb_perror_msg("cannot preserve %s of '%s'", "times", dest);
if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) {
bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
}
- return status;
+ return retval;
}