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glibc  2.9
fchown.c
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00001 /* Copyright (C) 2000, 2003, 2006 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <unistd.h>
00021 
00022 #include <sysdep.h>
00023 #include <sys/syscall.h>
00024 
00025 #include <linux/posix_types.h>
00026 #include <kernel-features.h>
00027 
00028 #ifdef __NR_fchown32
00029 # if __ASSUME_32BITUIDS == 0
00030 /* This variable is shared with all files that need to check for 32bit
00031    uids.  */
00032 extern int __libc_missing_32bit_uids;
00033 # endif
00034 #endif /* __NR_fchown32 */
00035 
00036 int
00037 __fchown (int fd, uid_t owner, gid_t group)
00038 {
00039 #if  __ASSUME_32BITUIDS > 0
00040   return INLINE_SYSCALL (fchown32, 3, fd, owner, group);
00041 #else
00042 # ifdef __NR_fchown32
00043   if (__libc_missing_32bit_uids <= 0)
00044     {
00045       int result;
00046       int saved_errno = errno;
00047 
00048       result = INLINE_SYSCALL (fchown32, 3, fd, owner, group);
00049       if (result == 0 || errno != ENOSYS)
00050        return result;
00051 
00052       __set_errno (saved_errno);
00053       __libc_missing_32bit_uids = 1;
00054     }
00055 # endif /* __NR_fchown32 */
00056 
00057   if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U))
00058       || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
00059     {
00060       __set_errno (EINVAL);
00061       return -1;
00062     }
00063 
00064   return INLINE_SYSCALL (fchown, 3, fd, owner, group);
00065 #endif
00066 }
00067 
00068 weak_alias (__fchown, fchown)