/*
* Mini copy_file implementation for busybox
*
- *
* Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
+ * SELinux support by Yuichi Nakamura <ynakam@hitachisoft.jp>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
*/
-#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"
+// 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 softlink, we overwrite softlink's 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...
+//
+// 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)
+{
+ int e = errno;
+#if DO_POSIX_CP
+ if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) {
+ // 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 "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) {
+#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)
+}
+
+/* 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 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 = 1;
- int status = 0;
-
- if (((flags & FILEUTILS_PRESERVE_SYMLINKS) &&
- lstat(source, &source_stat) < 0) ||
- (!(flags & FILEUTILS_PRESERVE_SYMLINKS) &&
- stat(source, &source_stat) < 0)) {
- perror_msg("%s", source);
+ signed char retval = 0;
+ signed char dest_exists = 0;
+ signed char ovr;
+
+#define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE)
+
+ 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("cannot stat '%s'", source);
return -1;
}
- if (stat(dest, &dest_stat) < 0) {
+ if (lstat(dest, &dest_stat) < 0) {
if (errno != ENOENT) {
- perror_msg("unable to stat `%s'", dest);
+ bb_perror_msg("cannot 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;
}
- dest_exists = 0;
+ dest_exists = 1;
}
- if (dest_exists && source_stat.st_rdev == dest_stat.st_rdev &&
- source_stat.st_ino == dest_stat.st_ino) {
- error_msg("`%s' and `%s' are the same file", source, dest);
- return -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("cannot set setfscreatecon %s", con);
+ freecon(con);
+ return -1;
+ }
+ } else if (errno == ENOTSUP || errno == ENODATA) {
+ setfscreatecon_or_die(NULL);
+ } else {
+ bb_perror_msg("cannot 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)) {
- 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. */
+ /* Create DEST */
if (dest_exists) {
if (!S_ISDIR(dest_stat.st_mode)) {
- 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 {
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);
- perror_msg("cannot create directory `%s'", dest);
+ 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;
+ }
}
-
- /* Recursively copy files in SOURCE. */
- if ((dp = opendir(source)) == NULL) {
- perror_msg("unable to open directory `%s'", source);
- status = -1;
- goto end;
+ /* 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;
- if (strcmp(d->d_name, ".") == 0 ||
- strcmp(d->d_name, "..") == 0)
+ new_source = concat_subpath_file(source, d->d_name);
+ if (new_source == NULL)
continue;
-
- new_source = concat_path_file(source, d->d_name);
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);
}
+ closedir(dp);
- /* ??? What if an error occurs in readdir? */
-
- if (closedir(dp) < 0) {
- perror_msg("unable to close directory `%s'", source);
- status = -1;
+ if (!dest_exists
+ && chmod(dest, source_stat.st_mode & ~saved_umask) < 0
+ ) {
+ bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
+ /* retval = -1; - WRONG! copy *WAS* made */
}
+ goto preserve_mode_ugid_time;
+ }
- if (!dest_exists &&
- chmod(dest, source_stat.st_mode & ~saved_umask) < 0) {
- perror_msg("unable to change permissions of `%s'", dest);
- status = -1;
- }
- } else if (S_ISREG(source_stat.st_mode)) {
- FILE *sfp, *dfp=NULL;
-
- if (dest_exists) {
- if (flags & FILEUTILS_INTERACTIVE) {
- fprintf(stderr, "%s: overwrite `%s'? ", applet_name, dest);
- if (!ask_confirmation())
- 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("cannot create link '%s'", dest);
+ return -1;
}
+ }
+ /* _Not_ jumping to preserve_mode_ugid_time:
+ * hard/softlinks don't have those */
+ return 0;
+ }
- if ((dfp = fopen(dest, "w")) == NULL) {
- if (!(flags & FILEUTILS_FORCE)) {
- perror_msg("unable to open `%s'", dest);
- return -1;
- }
-
- if (unlink(dest) < 0) {
- perror_msg("unable to remove `%s'", dest);
- return -1;
+ if (S_ISREG(source_stat.st_mode)
+ /* DEREF uses stat, which never returns S_ISLNK() == true. */
+ /* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */
+ ) {
+ int src_fd;
+ int dst_fd;
+
+ 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;
+ }
}
-
- dest_exists = 0;
+ return 0;
}
+ add_to_ino_dev_hashtable(&source_stat, dest);
}
- if (!dest_exists) {
- int fd;
+ src_fd = open_or_warn(source, O_RDONLY);
+ if (src_fd < 0)
+ return -1;
- if ((fd = open(dest, O_WRONLY|O_CREAT, source_stat.st_mode)) < 0 ||
- (dfp = fdopen(fd, "w")) == NULL) {
- if (fd >= 0)
- close(fd);
- perror_msg("unable to open `%s'", dest);
+ /* 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, source_stat.st_mode);
+ } else /* safe way: */
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, source_stat.st_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, source_stat.st_mode);
+ if (dst_fd < 0) {
+ close(src_fd);
return -1;
}
}
- if ((sfp = fopen(source, "r")) == NULL) {
- fclose(dfp);
- perror_msg("unable to open `%s'", source);
- status = -1;
- goto end;
+#if ENABLE_SELINUX
+ if (((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT)
+ || (flags & FILEUTILS_SET_SECURITY_CONTEXT))
+ && is_selinux_enabled() > 0
+ ) {
+ security_context_t con;
+ if (getfscreatecon(&con) == -1) {
+ bb_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);
+ }
}
-
- if (copy_file_chunk(sfp, dfp, -1) < 0)
- status = -1;
-
- if (fclose(dfp) < 0) {
- perror_msg("unable to close `%s'", dest);
- status = -1;
+#endif
+ if (bb_copyfd_eof(src_fd, dst_fd) == -1)
+ retval = -1;
+ /* Ok, writing side I can understand... */
+ if (close(dst_fd) < 0) {
+ bb_perror_msg("cannot close '%s'", dest);
+ retval = -1;
}
+ /* ...but read size is already checked by bb_copyfd_eof */
+ close(src_fd);
+ goto preserve_mode_ugid_time;
+ }
- if (fclose(sfp) < 0) {
- perror_msg("unable to close `%s'", source);
- status = -1;
+ /* 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);
+ return -1;
+ }
+ 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);
}
- } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) ||
- S_ISSOCK(source_stat.st_mode)) {
+ /* _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) {
- perror_msg("unable to create `%s'", dest);
- return -1;
- }
- } else if (S_ISFIFO(source_stat.st_mode)) {
- if (mkfifo(dest, source_stat.st_mode) < 0) {
- perror_msg("cannot create fifo `%s'", dest);
- return -1;
- }
- } else if (S_ISLNK(source_stat.st_mode)) {
- char *lpath = xreadlink(source);
- if (symlink(lpath, dest) < 0) {
- perror_msg("cannot create symlink `%s'", dest);
+ bb_perror_msg("cannot create '%s'", dest);
return -1;
}
- free(lpath);
-
-#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
- if (flags & FILEUTILS_PRESERVE_STATUS)
- if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
- perror_msg("unable to preserve ownership of `%s'", dest);
-#endif
- return 0;
} else {
- error_msg("internal error: unrecognized file type");
+ bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode);
return -1;
}
-end:
+ preserve_mode_ugid_time:
- if (flags & FILEUTILS_PRESERVE_STATUS) {
+ if (flags & FILEUTILS_PRESERVE_STATUS
+ /* Cannot happen: */
+ /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */
+ ) {
struct utimbuf times;
times.actime = source_stat.st_atime;
times.modtime = source_stat.st_mtime;
+ /* BTW, utimes sets usec-precision time - just FYI */
if (utime(dest, ×) < 0)
- perror_msg("unable to preserve times of `%s'", dest);
+ bb_perror_msg("cannot 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);
- perror_msg("unable to preserve ownership of `%s'", dest);
+ bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
}
if (chmod(dest, source_stat.st_mode) < 0)
- perror_msg("unable to preserve permissions of `%s'", dest);
+ bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
}
- return status;
+ return retval;
}
projects / oweals / busybox.git / blobdiff