libsyscall/wrappers/unix03/fchmod.c

   1 /*
   2  * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <sys/cdefs.h>
  25
  26 #if __DARWIN_UNIX03
  27
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include "_errno.h"
  31
  32 extern int __fchmod(int fd, mode_t mode);
  33
  34 /*
  35  * fchmod stub, ignore S_ISUID and/or S_ISGID on EPERM,
  36  * mandated for conformance.
  37  *
  38  * This is for UNIX03 only.
  39  */
  40 int
  41 fchmod(int fd, mode_t mode)
  42 {
  43         int res = __fchmod(fd, mode);
  44
  45         if (res >= 0 || errno != EPERM || (mode & (S_ISUID | S_ISGID)) == 0) {
  46                 return res;
  47         }
  48         if (mode & S_ISGID) {
  49                 res = __fchmod(fd, mode ^ S_ISGID);
  50                 if (res >= 0 || errno != EPERM) {
  51                         return res;
  52                 }
  53         }
  54         if (mode & S_ISUID) {
  55                 res = __fchmod(fd, mode ^ S_ISUID);
  56                 if (res >= 0 || errno != EPERM) {
  57                         return res;
  58                 }
  59         }
  60         if ((mode & (S_ISUID | S_ISGID)) == (S_ISUID | S_ISGID)) {
  61                 res = __fchmod(fd, mode ^ (S_ISUID | S_ISGID));
  62         }
  63         return res;
  64 }
  65
  66 #endif /* __DARWIN_UNIX03 */