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/*
* Copyright (c) 2008-2010, 2012, 2013 Wind River Systems; see
* guts/COPYRIGHT for information.
*
* static int
* wrap_fchmodat(int dirfd, const char *path, mode_t mode, int flags) {
* int rc = -1;
*/
PSEUDO_STATBUF buf;
int save_errno = errno;
static int picky_fchmodat = 0;
#ifdef PSEUDO_NO_REAL_AT_FUNCTIONS
if (dirfd != AT_FDCWD) {
errno = ENOSYS;
return -1;
}
if (flags & AT_SYMLINK_NOFOLLOW) {
/* Linux, as of this writing, will always reject this.
* GNU tar relies on getting the rejection. To cut down
* on traffic, we check for the failure, and if we saw
* a failure previously, we reject it right away and tell
* the caller to retry.
*/
if (picky_fchmodat) {
errno = ENOTSUP;
return -1;
}
rc = base_lstat(path, &buf);
} else {
rc = base_stat(path, &buf);
}
#else
rc = base_fstatat(dirfd, path, &buf, flags);
#endif
if (rc == -1) {
return rc;
}
if (S_ISLNK(buf.st_mode)) {
/* we don't really support chmod of a symlink */
errno = ENOSYS;
return -1;
}
save_errno = errno;
#if 0
pseudo_msg_t *msg;
/* purely for debugging purposes: check whether file
* is already in database. We don't need the resulting
* information for anything. This is currently ifdefed
* out because it's only useful when trying to track where
* files are coming from.
*/
msg = pseudo_client_op(OP_STAT, 0, -1, -1, path, &buf);
if (!msg || msg->result != RESULT_SUCCEED) {
pseudo_debug(2, "chmodat to 0%o on %d/%s, ino %llu, new file.\n",
mode, dirfd, path, (unsigned long long) buf.st_ino);
}
#endif
/* user bits added so "root" can always access files. */
#ifdef PSEUDO_NO_REAL_AT_FUNCTIONS
/* note: if path was a symlink, and AT_SYMLINK_NOFOLLOW was
* specified, we already bailed previously. */
real_chmod(path, PSEUDO_FS_MODE(mode, S_ISDIR(buf.st_mode)));
#else
rc = real_fchmodat(dirfd, path, PSEUDO_FS_MODE(mode, S_ISDIR(buf.st_mode)), flags);
/* AT_SYMLINK_NOFOLLOW isn't supported by fchmodat. GNU tar
* tries to use it anyway, figuring it can just retry if that
* fails. So we want to report that *particular* failure instead
* of doing the fallback.
*/
if (rc == -1 && errno == ENOTSUP && (flags & AT_SYMLINK_NOFOLLOW)) {
picky_fchmodat = 1;
return -1;
}
#endif
/* we otherwise ignore failures from underlying fchmod, because pseudo
* may believe you are permitted to change modes that the filesystem
* doesn't. Note that we also don't need to know whether the
* file might be a (pseudo) block device or some such; pseudo
* will only modify permission bits based on an OP_CHMOD, and does
* not care about device/file type mismatches, only directory/file
* or symlink/file.
*/
buf.st_mode = (buf.st_mode & ~07777) | (mode & 07777);
pseudo_client_op(OP_CHMOD, 0, -1, dirfd, path, &buf);
/* don't change errno from what it was originally */
errno = save_errno;
rc = 0;
/* return rc;
* }
*/
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