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glibc  2.9
chown.c
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00001 /* Copyright (C) 1998,2000,2002,2003,2006 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 #include <bp-checks.h>
00025 
00026 #include <linux/posix_types.h>
00027 #include <kernel-features.h>
00028 
00029 #ifdef __NR_chown32
00030 # if __ASSUME_32BITUIDS == 0
00031 /* This variable is shared with all files that need to check for 32bit
00032    uids.  */
00033 extern int __libc_missing_32bit_uids;
00034 # endif
00035 #endif /* __NR_chown32 */
00036 
00037 int
00038 __chown (const char *file, uid_t owner, gid_t group)
00039 {
00040 #if __ASSUME_32BITUIDS > 0
00041   return INLINE_SYSCALL (chown32, 3, CHECK_STRING (file), owner, group);
00042 #else
00043 # ifdef __NR_chown32
00044   if (__libc_missing_32bit_uids <= 0)
00045     {
00046       int result;
00047       int saved_errno = errno;
00048 
00049       result = INLINE_SYSCALL (chown32, 3, CHECK_STRING (file), owner, group);
00050       if (result == 0 || errno != ENOSYS)
00051        return result;
00052 
00053       __set_errno (saved_errno);
00054       __libc_missing_32bit_uids = 1;
00055     }
00056 # endif /* __NR_chown32 */
00057 
00058   if (((owner + 1) > (gid_t) ((__kernel_uid_t) -1U))
00059       || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
00060     {
00061       __set_errno (EINVAL);
00062       return -1;
00063     }
00064 
00065   return INLINE_SYSCALL (chown, 3, CHECK_STRING (file), owner, group);
00066 #endif
00067 }
00068 libc_hidden_def (__chown)
00069 weak_alias (__chown, chown)