1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#ifndef _FCNTL_H
30#error "Never include this file directly; instead, include <fcntl.h>"
31#endif
32
33int __open_2(const char*, int) __INTRODUCED_IN(17);
34int __openat_2(int, const char*, int) __INTRODUCED_IN(17);
35/*
36 * These are the easiest way to call the real open even in clang FORTIFY.
37 */
38int __open_real(const char*, int, ...) __RENAME(open);
39int __openat_real(int, const char*, int, ...) __RENAME(openat);
40
41#if defined(__BIONIC_FORTIFY)
42#define __open_too_many_args_error "too many arguments"
43#define __open_too_few_args_error "called with O_CREAT or O_TMPFILE, but missing mode"
44#define __open_useless_modes_warning "has superfluous mode bits; missing O_CREAT?"
45/* O_TMPFILE shares bits with O_DIRECTORY. */
46#define __open_modes_useful(flags) (((flags) & O_CREAT) || ((flags) & O_TMPFILE) == O_TMPFILE)
47#if defined(__clang__)
48
49#if __ANDROID_API__ >= __ANDROID_API_J_MR1__
50__BIONIC_ERROR_FUNCTION_VISIBILITY
51int open(const char* pathname, int flags, mode_t modes, ...) __overloadable
52        __errorattr(__open_too_many_args_error);
53
54/*
55 * pass_object_size serves two purposes here, neither of which involve __bos: it
56 * disqualifies this function from having its address taken (so &open works),
57 * and it makes overload resolution prefer open(const char *, int) over
58 * open(const char *, int, ...).
59 */
60__BIONIC_FORTIFY_INLINE
61int open(const char* const __pass_object_size pathname, int flags)
62        __overloadable
63        __clang_error_if(__open_modes_useful(flags), "'open' " __open_too_few_args_error) {
64    return __open_2(pathname, flags);
65}
66
67__BIONIC_FORTIFY_INLINE
68int open(const char* const __pass_object_size pathname, int flags, mode_t modes)
69        __overloadable
70        __clang_warning_if(!__open_modes_useful(flags) && modes,
71                           "'open' " __open_useless_modes_warning) {
72    return __open_real(pathname, flags, modes);
73}
74
75__BIONIC_ERROR_FUNCTION_VISIBILITY
76int openat(int dirfd, const char* pathname, int flags, mode_t modes, ...)
77        __overloadable
78        __errorattr(__open_too_many_args_error);
79
80__BIONIC_FORTIFY_INLINE
81int openat(int dirfd, const char* const __pass_object_size pathname, int flags)
82        __overloadable
83        __clang_error_if(__open_modes_useful(flags), "'openat' " __open_too_few_args_error) {
84    return __openat_2(dirfd, pathname, flags);
85}
86
87__BIONIC_FORTIFY_INLINE
88int openat(int dirfd, const char* const __pass_object_size pathname, int flags, mode_t modes)
89        __overloadable
90        __clang_warning_if(!__open_modes_useful(flags) && modes,
91                           "'openat' " __open_useless_modes_warning) {
92    return __openat_real(dirfd, pathname, flags, modes);
93}
94#endif /* __ANDROID_API__ >= __ANDROID_API_J_MR1__ */
95
96#else /* defined(__clang__) */
97__errordecl(__creat_missing_mode, __open_too_few_args_error);
98__errordecl(__creat_too_many_args, __open_too_many_args_error);
99
100#if __ANDROID_API__ >= __ANDROID_API_J_MR1__
101__BIONIC_FORTIFY_VARIADIC
102int open(const char* pathname, int flags, ...) {
103    if (__builtin_constant_p(flags)) {
104        if (__open_modes_useful(flags) && __builtin_va_arg_pack_len() == 0) {
105            __creat_missing_mode();  /* Compile time error. */
106        }
107    }
108
109    if (__builtin_va_arg_pack_len() > 1) {
110        __creat_too_many_args();  /* Compile time error. */
111    }
112
113    if ((__builtin_va_arg_pack_len() == 0) && !__builtin_constant_p(flags)) {
114        return __open_2(pathname, flags);
115    }
116
117    return __open_real(pathname, flags, __builtin_va_arg_pack());
118}
119
120__BIONIC_FORTIFY_VARIADIC
121int openat(int dirfd, const char* pathname, int flags, ...) {
122    if (__builtin_constant_p(flags)) {
123        if (__open_modes_useful(flags) && __builtin_va_arg_pack_len() == 0) {
124            __creat_missing_mode();  /* Compile time error. */
125        }
126    }
127
128    if (__builtin_va_arg_pack_len() > 1) {
129        __creat_too_many_args();  /* Compile time error. */
130    }
131
132    if ((__builtin_va_arg_pack_len() == 0) && !__builtin_constant_p(flags)) {
133        return __openat_2(dirfd, pathname, flags);
134    }
135
136    return __openat_real(dirfd, pathname, flags, __builtin_va_arg_pack());
137}
138#endif /* __ANDROID_API__ >= __ANDROID_API_J_MR1__ */
139
140#endif /* defined(__clang__) */
141
142#undef __open_too_many_args_error
143#undef __open_too_few_args_error
144#undef __open_useless_modes_warning
145#undef __open_modes_useful
146#endif /* defined(__BIONIC_FORTIFY) */
147