mirror of
https://github.com/sheumann/hush.git
synced 2024-08-27 03:29:05 +00:00
394 lines
11 KiB
C
394 lines
11 KiB
C
/* 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_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 */
|
|
}
|
|
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;
|
|
}
|
|
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 (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;
|
|
|
|
// POSIX way is a security problem versus (sym)link attacks
|
|
if (!ENABLE_FEATURE_NON_POSIX_CP) {
|
|
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) {
|
|
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_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 (bb_copyfd_eof(src_fd, dst_fd) == -1)
|
|
retval = -1;
|
|
/* 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);
|
|
free(lpath);
|
|
if (r < 0) {
|
|
bb_perror_msg("can't 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("can't preserve %s of '%s'", "ownership", dest);
|
|
}
|
|
/* _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("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);
|
|
}
|
|
|
|
return retval;
|
|
}
|