1/*
2 * Copyright (c) 2007,2017,2023 Apple Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24#ifndef _STRING_H_
25# error "Never use <secure/_string.h> directly; include <string.h> instead."
26#endif
27
28#ifndef _SECURE__STRING_H_
29#define _SECURE__STRING_H_
30
31#include <sys/cdefs.h>
32#include <Availability.h>
33#include <secure/_common.h>
34
35#if _USE_FORTIFY_LEVEL > 0
36
37#ifdef __LIBC_STAGED_BOUNDS_SAFETY_ATTRIBUTES
38
39#if __has_builtin(__builtin___memcpy_chk)
40static inline void *_LIBC_SIZE(__n)
41__memcpy_ptrchk(void *const _LIBC_SIZE(__n) __darwin_pass_obsz0 __dst, const void *_LIBC_SIZE(__n) __src, size_t __n) {
42 return _LIBC_FORGE_PTR(__builtin___memcpy_chk(__dst, __src, __n, __darwin_obsz0(__dst)), __n);
43}
44#define __memcpy_chk_func __memcpy_ptrchk
45#endif
46
47#if __has_builtin(__builtin___memmove_chk)
48static inline void *_LIBC_SIZE(__n)
49__memmove_ptrchk(void *const _LIBC_SIZE(__n) __darwin_pass_obsz0 __dst, const void *_LIBC_SIZE(__n) __src, size_t __n) {
50 return _LIBC_FORGE_PTR(__builtin___memmove_chk(__dst, __src, __n, __darwin_obsz0(__dst)), __n);
51}
52#define __memmove_chk_func __memmove_ptrchk
53#endif
54
55#if __has_builtin(__builtin___memset_chk)
56static inline void *_LIBC_SIZE(__n)
57__memset_ptrchk(void *const _LIBC_SIZE(__n) __darwin_pass_obsz0 __dst, int __c, size_t __n) {
58 return _LIBC_FORGE_PTR(__builtin___memset_chk(__dst, __c, __n, __darwin_obsz0(__dst)), __n);
59}
60#define __memset_chk_func __memset_ptrchk
61#endif
62
63#undef __stpncpy_chk_func /* stpncpy unavailable */
64#undef __strncpy_chk_func /* strncpy unavailable */
65
66#if __has_builtin(__builtin___strlcpy_chk)
67static inline size_t
68__strlcpy_ptrchk(char *const _LIBC_SIZE(__n) __darwin_pass_obsz __dst, const char *__src, size_t __n) {
69 return __builtin___strlcpy_chk(__dst, __src, __n, __darwin_obsz(__dst));
70}
71#define __strlcpy_chk_func __strlcpy_ptrchk
72#endif
73
74#if __has_builtin(__builtin___strlcat_chk)
75static inline size_t
76__strlcat_ptrchk(char *const _LIBC_SIZE(__n) __darwin_pass_obsz __dst, const char *__src, size_t __n) {
77 return __builtin___strlcat_chk(__dst, __src, __n, __darwin_obsz(__dst));
78}
79#define __strlcat_chk_func __strlcat_ptrchk
80#endif
81
82#if __has_builtin(__builtin___memccpy_chk)
83static inline void *_LIBC_SIZE(__n)
84__memccpy_ptrchk(void *const _LIBC_SIZE(__n) __darwin_pass_obsz0 __dst, const void *_LIBC_SIZE(__n) __src, int __c, size_t __n) {
85 return _LIBC_FORGE_PTR(__builtin___memccpy_chk(__dst, __src, __c, __n, __darwin_obsz0(__dst)), __n);
86}
87#define __memccpy_chk_func __memccpy_ptrchk
88#endif
89
90#undef __strcpy_chk_func /* strcpy unavailable */
91#undef __stpcpy_chk_func /* stpcpy unavailable */
92#undef __strcat_chk_func /* strcat unavailable */
93#undef __strncat_chk_func /* strncat unavailable */
94
95#else /* __LIBC_STAGED_BOUNDS_SAFETY_ATTRIBUTES */
96
97#define __is_modern_darwin(ios, macos) \
98 (__IPHONE_OS_VERSION_MIN_REQUIRED >= (ios) || \
99 __MAC_OS_X_VERSION_MIN_REQUIRED >= (macos) || \
100 defined(__DRIVERKIT_VERSION_MIN_REQUIRED))
101
102/* __is_gcc(gcc_major, gcc_minor)
103 * Special values:
104 * 10.0 means "test should always fail when __has_builtin isn't supported"
105 (because gcc got __has_builtin in version 10.0); this is used for builtins
106 that gcc did not support yet at the time __has_builtin was introduced, so
107 there is no point checking the compiler version.
108 * 0.0 means that we did not research when gcc started supporting this builtin,
109 but it's believed to have been the case at least since gcc 4.0, which came
110 out in 2005. (Hello from 2025! What year is it now? Can't believe we're still
111 using C!)
112 */
113#define __is_gcc(major, minor) \
114 (__GNUC__ > (gcc_major) || \
115 (__GNUC__ == (gcc_major) && __GNUC_MINOR__ >= (gcc_minor)))
116
117#ifdef __has_builtin
118#define __supports_builtin(builtin, gcc_major, gcc_minor) \
119 __has_builtin(builtin)
120#else
121#define __supports_builtin(builtin, gcc_major, gcc_minor) __is_gcc(gcc_major, gcc_minor)
122#endif
123
124
125#if __supports_builtin(__builtin___memcpy_chk, 0, 0)
126#define __memcpy_chk_func(dest, ...) \
127 __builtin___memcpy_chk (dest, __VA_ARGS__, __darwin_obsz0 (dest))
128#endif
129
130#if __supports_builtin(__builtin___memmove_chk, 0, 0)
131#define __memmove_chk_func(dest, ...) \
132 __builtin___memmove_chk (dest, __VA_ARGS__, __darwin_obsz0 (dest))
133#endif
134
135#if __supports_builtin(__builtin___memset_chk, 0, 0)
136#define __memset_chk_func(dest, ...) \
137 __builtin___memset_chk (dest, __VA_ARGS__, __darwin_obsz0 (dest))
138#endif
139
140#if __supports_builtin(__builtin___stpncpy_chk, 4, 7)
141#define __stpncpy_chk_func(dest, ...) \
142 __builtin___stpncpy_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
143#endif
144
145#if __supports_builtin(__builtin___strncpy_chk, 0, 0)
146#define __strncpy_chk_func(dest, ...) \
147 __builtin___strncpy_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
148#endif
149
150#if __is_modern_darwin(70000, 1090)
151
152#if __supports_builtin(__builtin___strlcpy_chk, 0, 0)
153#define __strlcpy_chk_func(dest, ...) \
154 __builtin___strlcpy_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
155#endif
156
157#if __supports_builtin(__builtin___strlcat_chk, 0, 0)
158#define __strlcat_chk_func(dest, ...) \
159 __builtin___strlcat_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
160#endif
161
162#if __supports_builtin(__builtin___memccpy_chk, 10, 0)
163#define __memccpy_chk_func(dest, ...) \
164 __builtin___memccpy_chk (dest, __VA_ARGS__, __darwin_obsz0 (dest))
165#endif
166
167#endif /* __is_modern_darwin(70000, 1090) */
168
169
170#if __supports_builtin(__builtin___strcpy_chk, 0, 0)
171#define __strcpy_chk_func(dest, ...) \
172 __builtin___strcpy_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
173#endif
174
175#if __supports_builtin(__builtin___stpcpy_chk, 0, 0)
176#define __stpcpy_chk_func(dest, ...) \
177 __builtin___stpcpy_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
178#endif
179
180#if __supports_builtin(__builtin___strcat_chk, 0, 0)
181#define __strcat_chk_func(dest, ...) \
182 __builtin___strcat_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
183#endif
184
185#if ! (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED < 32000)
186#if __supports_builtin(__builtin___strncat_chk, 0, 0)
187#define __strncat_chk_func(dest, ...) \
188 __builtin___strncat_chk (dest, __VA_ARGS__, __darwin_obsz (dest))
189#endif
190#endif
191
192
193#undef __supports_builtin
194#undef __is_gcc
195
196#endif /* defined(__has_ptrcheck) && __has_ptrcheck */
197
198#undef __is_modern_darwin
199
200/* memccpy, memcpy, mempcpy, memmove, memset, strcpy, strlcpy, stpcpy,
201 strncpy, stpncpy, strcat, strlcat, and strncat */
202
203/* The use of .../__VA_ARGS__ is load-bearing. If the macros take fixed
204 * arguments, they are unable to themselves accept macros that expand to
205 * multiple arguments, like this:
206 * #define memcpy(a, b, c) ...
207 * #define FOO(data) get_bytes(data), get_length(data)
208 * memcpy(bar, FOO(d));
209 * This will fail because the preprocessor only sees two arguments on the first
210 * expansion of memcpy, when 3 are required.
211 * This is also required to support syntaxes that embed commas. The preprocessor
212 * recognizes parentheses for the isolation of arguments but not brackets. This
213 * expands to 3 arguments:
214 * strcpy(destination, [NSString stringWithFormat:@"%i", 4].UTF8String);
215 * ^ ^ ^
216 * |destination | |
217 * |[NSString stringWithFormat:@"%i" |
218 * |4].UTF8String
219 * This expands to 4 arguments:
220 * memcpy(destination, (uint8_t[]) { 1, 2 }, 2);
221 * ^ ^ ^ ^
222 * To work correctly under these hostile circumstances, chk_func macros
223 * need to expand to a bare identifier (like #define memcpy_chk_func __memcpy)
224 * or to a macro that also takes variadic arguments.
225 */
226
227#ifdef __memccpy_chk_func
228#undef memccpy
229#define memccpy(...) __memccpy_chk_func (__VA_ARGS__)
230#endif
231
232#ifdef __memcpy_chk_func
233#undef memcpy
234#define memcpy(...) __memcpy_chk_func (__VA_ARGS__)
235#endif
236
237#ifdef __memmove_chk_func
238#undef memmove
239#define memmove(...) __memmove_chk_func (__VA_ARGS__)
240#endif
241
242#ifdef __memset_chk_func
243#undef memset
244#define memset(...) __memset_chk_func (__VA_ARGS__)
245#endif
246
247#if defined(__strcpy_chk_func)
248#undef strcpy
249#define strcpy(...) __strcpy_chk_func (__VA_ARGS__)
250#endif
251
252#if defined(__strcat_chk_func)
253#undef strcat
254#define strcat(...) __strcat_chk_func (__VA_ARGS__)
255#endif
256
257#if defined(__strncpy_chk_func)
258#undef strncpy
259#define strncpy(...) __strncpy_chk_func (__VA_ARGS__)
260#endif
261
262#if defined(__strncat_chk_func)
263#undef strncat
264#define strncat(...) __strncat_chk_func (__VA_ARGS__)
265#endif
266
267#if __DARWIN_C_LEVEL >= 200809L
268
269#if defined(__stpcpy_chk_func)
270#undef stpcpy
271#define stpcpy(...) __stpcpy_chk_func (__VA_ARGS__)
272#endif
273
274#if defined(__stpncpy_chk_func)
275#undef stpncpy
276#define stpncpy(...) __stpncpy_chk_func (__VA_ARGS__)
277#endif
278
279#endif /* __DARWIN_C_LEVEL >= 200809L */
280
281#if __DARWIN_C_LEVEL >= __DARWIN_C_FULL
282#if defined(__strlcpy_chk_func)
283#undef strlcpy
284#define strlcpy(...) __strlcpy_chk_func (__VA_ARGS__)
285#endif
286
287#if defined(__strlcat_chk_func)
288#undef strlcat
289#define strlcat(...) __strlcat_chk_func (__VA_ARGS__)
290#endif
291#endif /* __DARWIN_C_LEVEL >= __DARWIN_C_FULL */
292
293#endif /* _USE_FORTIFY_LEVEL > 0 */
294
295#endif /* _SECURE__STRING_H_ */