1 /* Copyright (C) 2005, 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 #include <sys/syscall.h>
27 #include <bp-checks.h>
29 #include <linux/posix_types.h>
30 #include <kernel-features.h>
33 # if __ASSUME_32BITUIDS == 0
34 /* This variable is shared with all files that need to check for 32bit
36 extern int __libc_missing_32bit_uids;
38 #endif /* __NR_chown32 */
41 fchownat (int fd, const char *file, uid_t owner, gid_t group, int flag)
43 if (flag & ~AT_SYMLINK_NOFOLLOW)
51 if (fd != AT_FDCWD && file[0] != '/')
53 size_t filelen = strlen (file);
54 static const char procfd[] = "/proc/self/fd/%d/%s";
55 /* Buffer for the path name we are going to use. It consists of
56 - the string /proc/self/fd/
57 - the file descriptor number
58 - the file name provided.
59 The final NUL is included in the sizeof. A bit of overhead
60 due to the format elements compensates for possible negative
62 size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
63 buf = alloca (buflen);
65 __snprintf (buf, buflen, procfd, fd, file);
70 INTERNAL_SYSCALL_DECL (err);
72 #if __ASSUME_32BITUIDS > 0
73 if (flag & AT_SYMLINK_NOFOLLOW)
74 result = INTERNAL_SYSCALL (lchown32, err, 3, CHECK_STRING (file), owner,
77 result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file), owner,
81 if (__libc_missing_32bit_uids <= 0)
83 if (flag & AT_SYMLINK_NOFOLLOW)
84 result = INTERNAL_SYSCALL (lchown32, err, 3, CHECK_STRING (file),
87 result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file), owner,
90 if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
92 if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS)
95 __libc_missing_32bit_uids = 1;
97 # endif /* __NR_chown32 */
99 if (((owner + 1) > (gid_t) ((__kernel_uid_t) -1U))
100 || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
102 __set_errno (EINVAL);
106 if (flag & AT_SYMLINK_NOFOLLOW)
107 result = INTERNAL_SYSCALL (lchown, err, 3, CHECK_STRING (file), owner,
110 result = INTERNAL_SYSCALL (chown, err, 3, CHECK_STRING (file), owner,
114 if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0))
117 __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);