* 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 tarball for details.
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <utime.h>
-#include <errno.h>
-#include <dirent.h>
-#include <stdlib.h>
-#include <string.h>
-
#include "libbb.h"
-/* Compiler version-specific crap that should be in a header file somewhere. */
+// 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 !((__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1))
-#define lchown chown
+#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) */
+}
-
-int copy_file(const char *source, const char *dest, int flags)
+/* 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;
- int dest_exists = 0;
- int status = 0;
-
- if ((!(flags & FILEUTILS_DEREFERENCE) &&
- lstat(source, &source_stat) < 0) ||
- ((flags & FILEUTILS_DEREFERENCE) &&
- stat(source, &source_stat) < 0)) {
- bb_perror_msg("%s", source);
+ 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("unable to stat `%s'", dest);
+ 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);
+ 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;
}
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("%s: omitting directory", source);
+ 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;
}
- /* Create DEST. */
if (dest_exists) {
if (!S_ISDIR(dest_stat.st_mode)) {
- bb_error_msg("`%s' is not a directory", dest);
+ 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("cannot create directory `%s'", dest);
+ 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;
+ }
}
-
- /* Recursively copy files in SOURCE. */
- if ((dp = bb_opendir(source)) == NULL) {
- status = -1;
- goto preserve_status;
+ /* 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)
+ if (new_source == NULL)
continue;
new_dest = concat_path_file(dest, d->d_name);
- if (copy_file(new_source, new_dest, flags) < 0)
- status = -1;
+ if (copy_file(new_source, new_dest, flags & ~FILEUTILS_DEREFERENCE_L0) < 0)
+ retval = -1;
free(new_source);
free(new_dest);
}
- /* closedir have only EBADF error, but "dp" not changes */
closedir(dp);
- if (!dest_exists &&
- chmod(dest, source_stat.st_mode & ~saved_umask) < 0) {
- bb_perror_msg("unable to change permissions of `%s'", dest);
- status = -1;
+ 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 */
}
- } else if (S_ISREG(source_stat.st_mode) || (flags & FILEUTILS_DEREFERENCE))
- {
- int src_fd;
- int dst_fd;
-#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS
- char *link_name;
+ goto preserve_mode_ugid_time;
+ }
- if (!(flags & FILEUTILS_DEREFERENCE) &&
- is_in_ino_dev_hashtable(&source_stat, &link_name)) {
- if (link(link_name, dest) < 0) {
- bb_perror_msg("unable to link `%s'", dest);
- return -1;
+ if (dest_exists) {
+ if (flags & FILEUTILS_UPDATE) {
+ if (source_stat.st_mtime <= dest_stat.st_mtime) {
+ return 0; /* source file must be newer */
}
-
- return 0;
}
- add_to_ino_dev_hashtable(&source_stat, dest);
-#endif
- src_fd = open(source, O_RDONLY);
- if (src_fd == -1) {
- bb_perror_msg("unable to open `%s'", source);
- return(-1);
+#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 (dest_exists) {
- if (flags & FILEUTILS_INTERACTIVE) {
- fprintf(stderr, "%s: overwrite `%s'? ", bb_applet_name, dest);
- if (!bb_ask_confirmation()) {
- close (src_fd);
- return 0;
- }
+ 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;
+ }
- dst_fd = open(dest, O_WRONLY|O_TRUNC);
- if (dst_fd == -1) {
- if (!(flags & FILEUTILS_FORCE)) {
- bb_perror_msg("unable to open `%s'", dest);
- close(src_fd);
- return -1;
- }
+ 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 (unlink(dest) < 0) {
- bb_perror_msg("unable to remove `%s'", dest);
- close(src_fd);
- return -1;
- }
+ if (!FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) {
+ /* "cp -d symlink dst": create a link */
+ goto dont_cat;
+ }
- goto dest_removed;
- }
- } else {
-dest_removed:
- dst_fd = open(dest, O_WRONLY|O_CREAT, source_stat.st_mode);
- if (dst_fd == -1) {
- bb_perror_msg("unable to open `%s'", dest);
- close(src_fd);
- return(-1);
+ 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);
}
- if (bb_copyfd_eof(src_fd, dst_fd) == -1)
- status = -1;
+ src_fd = open_or_warn(source, O_RDONLY);
+ if (src_fd < 0)
+ return -1;
- if (close(dst_fd) < 0) {
- bb_perror_msg("unable to close `%s'", dest);
- status = -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 (close(src_fd) < 0) {
- bb_perror_msg("unable to close `%s'", source);
- status = -1;
+ 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;
+ }
}
- } 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)) {
- if (dest_exists) {
- if((flags & FILEUTILS_FORCE) == 0) {
- fprintf(stderr, "`%s' exists\n", dest);
+#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(unlink(dest) < 0) {
- bb_perror_msg("unable to remove `%s'", dest);
- return -1;
+ if (con) {
+ if (setfilecon(dest, con) == -1) {
+ bb_perror_msg("setfilecon:%s,%s", dest, con);
+ freecon(con);
+ return -1;
+ }
+ freecon(con);
}
}
- 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;
+#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;
}
- } else if (S_ISLNK(source_stat.st_mode)) {
- char *lpath;
-
- lpath = xreadlink(source);
- if (symlink(lpath, dest) < 0) {
- bb_perror_msg("cannot create symlink `%s'", dest);
+ /* 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("unable to preserve ownership of `%s'", dest);
-
- return 0;
-
- } else {
- if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
- bb_perror_msg("unable to create `%s'", dest);
- return -1;
- }
+ 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("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) {
- struct utimbuf times;
- char *msg="unable to preserve %s of `%s'";
+ if (flags & FILEUTILS_PRESERVE_STATUS
+ /* Cannot happen: */
+ /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */
+ ) {
+ struct timeval times[2];
- times.actime = source_stat.st_atime;
- times.modtime = source_stat.st_mtime;
- if (utime(dest, ×) < 0)
- bb_perror_msg(msg, "times", dest);
+ 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(msg, "ownership", dest);
+ bb_perror_msg("can't preserve %s of '%s'", "ownership", dest);
}
if (chmod(dest, source_stat.st_mode) < 0)
- bb_perror_msg(msg, "permissions", dest);
+ 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 status;
+ return retval;
}
projects / oweals / busybox.git / blobdiff