[apple/xnu.git] / libsyscall / wrappers / unix03 / fchmod.c

/*
 * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 */

#include <sys/cdefs.h>

#if __DARWIN_UNIX03

#include <sys/types.h>
#include <sys/stat.h>
#include "_errno.h"

extern int __fchmod(int fd, mode_t mode);

/*
 * fchmod stub, ignore S_ISUID and/or S_ISGID on EPERM,
 * mandated for conformance.
 *
 * This is for UNIX03 only.
 */
int
fchmod(int fd, mode_t mode)
{
        int res = __fchmod(fd, mode);

        if (res >= 0 || errno != EPERM || (mode & (S_ISUID | S_ISGID)) == 0) {
                return res;
        }
        if (mode & S_ISGID) {
                res = __fchmod(fd, mode ^ S_ISGID);
                if (res >= 0 || errno != EPERM) {
                        return res;
                }
        }
        if (mode & S_ISUID) {
                res = __fchmod(fd, mode ^ S_ISUID);
                if (res >= 0 || errno != EPERM) {
                        return res;
                }
        }
        if ((mode & (S_ISUID | S_ISGID)) == (S_ISUID | S_ISGID)) {
                res = __fchmod(fd, mode ^ (S_ISUID | S_ISGID));
        }
        return res;
}

#endif /* __DARWIN_UNIX03 */