diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/i386/fchownat.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/fchownat.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/fchownat.c b/sysdeps/unix/sysv/linux/i386/fchownat.c new file mode 100644 index 0000000000..331623f73d --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/fchownat.c @@ -0,0 +1,177 @@ +/* Copyright (C) 2005 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <unistd.h> + +#include <sysdep.h> +#include <sys/syscall.h> +#include <shlib-compat.h> +#include <bp-checks.h> + +#include <linux/posix_types.h> +#include "kernel-features.h" + +/* + In Linux 2.1.x the chown functions have been changed. A new function lchown + was introduced. The new chown now follows symlinks - the old chown and the + new lchown do not follow symlinks. + The new lchown function has the same number as the old chown had and the + new chown has a new number. When compiling with headers from Linux > 2.1.8x + it's impossible to run this libc with older kernels. In these cases libc + has therefore to route calls to chown to the old chown function. +*/ + +extern int __chown_is_lchown (const char *__file, uid_t __owner, + gid_t __group); +extern int __real_chown (const char *__file, uid_t __owner, gid_t __group); + + +#if defined __NR_lchown || __ASSUME_LCHOWN_SYSCALL > 0 +/* Running under Linux > 2.1.80. */ + +# ifdef __NR_chown32 +# if __ASSUME_32BITUIDS == 0 +/* This variable is shared with all files that need to check for 32bit + uids. */ +extern int __libc_missing_32bit_uids; +# endif +# endif /* __NR_chown32 */ +#endif + + +int +fchownat (int fd, const char *file, uid_t owner, gid_t group, int flag) +{ + if (flag & ~AT_SYMLINK_NOFOLLOW) + { + __set_errno (EINVAL); + return -1; + } + + char *buf = NULL; + + if (fd != AT_FDCWD && file[0] != '/') + { + size_t filelen = strlen (file); + static const char procfd[] = "/proc/self/fd/%d/%s"; + /* Buffer for the path name we are going to use. It consists of + - the string /proc/self/fd/ + - the file descriptor number + - the file name provided. + The final NUL is included in the sizeof. A bit of overhead + due to the format elements compensates for possible negative + numbers. */ + size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen; + buf = alloca (buflen); + + __snprintf (buf, buflen, procfd, fd, file); + file = buf; + } + + int result; + INTERNAL_SYSCALL_DECL (err); + +#if defined __NR_lchown || __ASSUME_LCHOWN_SYSCALL > 0 +# if __ASSUME_LCHOWN_SYSCALL == 0 + static int __libc_old_chown; + +# ifdef __NR_chown32 + if (__libc_missing_32bit_uids <= 0) + { + if (flag & AT_SYMLINK_NOFOLLOW) + result = INTERNAL_SYSCALL (lchown32, err, 3, CHECK_STRING (file), + owner, group); + else + result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file), + owner, group); + + if (!INTERNAL_SYSCALL_ERROR_P (result, err)) + return result; + if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS) + goto fail; + + __libc_missing_32bit_uids = 1; + } +# endif /* __NR_chown32 */ + + if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U)) + || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U))) + { + __set_errno (EINVAL); + return -1; + } + + if (!__libc_old_chown && (flag & AT_SYMLINK_NOFOLLOW) == 0) + { + result = INTERNAL_SYSCALL (chown, err, 3, CHECK_STRING (file), owner, + group); + + if (!INTERNAL_SYSCALL_ERROR_P (result, err)) + return result; + if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS) + goto fail; + + __libc_old_chown = 1; + } + + result = INTERNAL_SYSCALL (lchown, err, 3, CHECK_STRING (file), owner, + group); +# elif __ASSUME_32BITUIDS + /* This implies __ASSUME_LCHOWN_SYSCALL. */ + result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file), owner, + group); +# else + /* !__ASSUME_32BITUIDS && ASSUME_LCHOWN_SYSCALL */ +# ifdef __NR_chown32 + if (__libc_missing_32bit_uids <= 0) + { + result = INTERNAL_SYSCALL (chown32, err, 3, CHECK_STRING (file), owner, + group); + if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1)) + return result; + if (INTERNAL_SYSCALL_ERRNO (result, err) != ENOSYS) + goto fail; + + __libc_missing_32bit_uids = 1; + } +# endif /* __NR_chown32 */ + if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U)) + || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U))) + { + __set_errno (EINVAL); + return -1; + } + + result = INTERNAL_SYSCALL (chown, err, 3, CHECK_STRING (file), owner, group); +# endif +#else + result = INTERNAL_SYSCALL (chown, err, 3, CHECK_STRING (file), owner, group); +#endif + + if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0)) + { + fail: + __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf); + result = -1; + } + + return result; +} |