1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_STRING_H_ |
3 | #define _LINUX_STRING_H_ |
4 | |
5 | #include <linux/array_size.h> |
6 | #include <linux/compiler.h> /* for inline */ |
7 | #include <linux/types.h> /* for size_t */ |
8 | #include <linux/stddef.h> /* for NULL */ |
9 | #include <linux/err.h> /* for ERR_PTR() */ |
10 | #include <linux/errno.h> /* for E2BIG */ |
11 | #include <linux/overflow.h> /* for check_mul_overflow() */ |
12 | #include <linux/stdarg.h> |
13 | #include <uapi/linux/string.h> |
14 | |
15 | extern char *strndup_user(const char __user *, long); |
16 | extern void *memdup_user(const void __user *, size_t); |
17 | extern void *vmemdup_user(const void __user *, size_t); |
18 | extern void *memdup_user_nul(const void __user *, size_t); |
19 | |
20 | /** |
21 | * memdup_array_user - duplicate array from user space |
22 | * @src: source address in user space |
23 | * @n: number of array members to copy |
24 | * @size: size of one array member |
25 | * |
26 | * Return: an ERR_PTR() on failure. Result is physically |
27 | * contiguous, to be freed by kfree(). |
28 | */ |
29 | static inline void *memdup_array_user(const void __user *src, size_t n, size_t size) |
30 | { |
31 | size_t nbytes; |
32 | |
33 | if (check_mul_overflow(n, size, &nbytes)) |
34 | return ERR_PTR(error: -EOVERFLOW); |
35 | |
36 | return memdup_user(src, nbytes); |
37 | } |
38 | |
39 | /** |
40 | * vmemdup_array_user - duplicate array from user space |
41 | * @src: source address in user space |
42 | * @n: number of array members to copy |
43 | * @size: size of one array member |
44 | * |
45 | * Return: an ERR_PTR() on failure. Result may be not |
46 | * physically contiguous. Use kvfree() to free. |
47 | */ |
48 | static inline void *vmemdup_array_user(const void __user *src, size_t n, size_t size) |
49 | { |
50 | size_t nbytes; |
51 | |
52 | if (check_mul_overflow(n, size, &nbytes)) |
53 | return ERR_PTR(error: -EOVERFLOW); |
54 | |
55 | return vmemdup_user(src, nbytes); |
56 | } |
57 | |
58 | /* |
59 | * Include machine specific inline routines |
60 | */ |
61 | #include <asm/string.h> |
62 | |
63 | #ifndef __HAVE_ARCH_STRCPY |
64 | extern char * strcpy(char *,const char *); |
65 | #endif |
66 | #ifndef __HAVE_ARCH_STRNCPY |
67 | extern char * strncpy(char *,const char *, __kernel_size_t); |
68 | #endif |
69 | #ifndef __HAVE_ARCH_STRLCPY |
70 | size_t strlcpy(char *, const char *, size_t); |
71 | #endif |
72 | #ifndef __HAVE_ARCH_STRSCPY |
73 | ssize_t strscpy(char *, const char *, size_t); |
74 | #endif |
75 | |
76 | /* Wraps calls to strscpy()/memset(), no arch specific code required */ |
77 | ssize_t strscpy_pad(char *dest, const char *src, size_t count); |
78 | |
79 | #ifndef __HAVE_ARCH_STRCAT |
80 | extern char * strcat(char *, const char *); |
81 | #endif |
82 | #ifndef __HAVE_ARCH_STRNCAT |
83 | extern char * strncat(char *, const char *, __kernel_size_t); |
84 | #endif |
85 | #ifndef __HAVE_ARCH_STRLCAT |
86 | extern size_t strlcat(char *, const char *, __kernel_size_t); |
87 | #endif |
88 | #ifndef __HAVE_ARCH_STRCMP |
89 | extern int strcmp(const char *,const char *); |
90 | #endif |
91 | #ifndef __HAVE_ARCH_STRNCMP |
92 | extern int strncmp(const char *,const char *,__kernel_size_t); |
93 | #endif |
94 | #ifndef __HAVE_ARCH_STRCASECMP |
95 | extern int strcasecmp(const char *s1, const char *s2); |
96 | #endif |
97 | #ifndef __HAVE_ARCH_STRNCASECMP |
98 | extern int strncasecmp(const char *s1, const char *s2, size_t n); |
99 | #endif |
100 | #ifndef __HAVE_ARCH_STRCHR |
101 | extern char * strchr(const char *,int); |
102 | #endif |
103 | #ifndef __HAVE_ARCH_STRCHRNUL |
104 | extern char * strchrnul(const char *,int); |
105 | #endif |
106 | extern char * strnchrnul(const char *, size_t, int); |
107 | #ifndef __HAVE_ARCH_STRNCHR |
108 | extern char * strnchr(const char *, size_t, int); |
109 | #endif |
110 | #ifndef __HAVE_ARCH_STRRCHR |
111 | extern char * strrchr(const char *,int); |
112 | #endif |
113 | extern char * __must_check skip_spaces(const char *); |
114 | |
115 | extern char *strim(char *); |
116 | |
117 | static inline __must_check char *strstrip(char *str) |
118 | { |
119 | return strim(str); |
120 | } |
121 | |
122 | #ifndef __HAVE_ARCH_STRSTR |
123 | extern char * strstr(const char *, const char *); |
124 | #endif |
125 | #ifndef __HAVE_ARCH_STRNSTR |
126 | extern char * strnstr(const char *, const char *, size_t); |
127 | #endif |
128 | #ifndef __HAVE_ARCH_STRLEN |
129 | extern __kernel_size_t strlen(const char *); |
130 | #endif |
131 | #ifndef __HAVE_ARCH_STRNLEN |
132 | extern __kernel_size_t strnlen(const char *,__kernel_size_t); |
133 | #endif |
134 | #ifndef __HAVE_ARCH_STRPBRK |
135 | extern char * strpbrk(const char *,const char *); |
136 | #endif |
137 | #ifndef __HAVE_ARCH_STRSEP |
138 | extern char * strsep(char **,const char *); |
139 | #endif |
140 | #ifndef __HAVE_ARCH_STRSPN |
141 | extern __kernel_size_t strspn(const char *,const char *); |
142 | #endif |
143 | #ifndef __HAVE_ARCH_STRCSPN |
144 | extern __kernel_size_t strcspn(const char *,const char *); |
145 | #endif |
146 | |
147 | #ifndef __HAVE_ARCH_MEMSET |
148 | extern void * memset(void *,int,__kernel_size_t); |
149 | #endif |
150 | |
151 | #ifndef __HAVE_ARCH_MEMSET16 |
152 | extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); |
153 | #endif |
154 | |
155 | #ifndef __HAVE_ARCH_MEMSET32 |
156 | extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); |
157 | #endif |
158 | |
159 | #ifndef __HAVE_ARCH_MEMSET64 |
160 | extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); |
161 | #endif |
162 | |
163 | static inline void *memset_l(unsigned long *p, unsigned long v, |
164 | __kernel_size_t n) |
165 | { |
166 | if (BITS_PER_LONG == 32) |
167 | return memset32(s: (uint32_t *)p, v, n); |
168 | else |
169 | return memset64(s: (uint64_t *)p, v, n); |
170 | } |
171 | |
172 | static inline void *memset_p(void **p, void *v, __kernel_size_t n) |
173 | { |
174 | if (BITS_PER_LONG == 32) |
175 | return memset32(s: (uint32_t *)p, v: (uintptr_t)v, n); |
176 | else |
177 | return memset64(s: (uint64_t *)p, v: (uintptr_t)v, n); |
178 | } |
179 | |
180 | extern void **__memcat_p(void **a, void **b); |
181 | #define memcat_p(a, b) ({ \ |
182 | BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \ |
183 | "type mismatch in memcat_p()"); \ |
184 | (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \ |
185 | }) |
186 | |
187 | #ifndef __HAVE_ARCH_MEMCPY |
188 | extern void * memcpy(void *,const void *,__kernel_size_t); |
189 | #endif |
190 | #ifndef __HAVE_ARCH_MEMMOVE |
191 | extern void * memmove(void *,const void *,__kernel_size_t); |
192 | #endif |
193 | #ifndef __HAVE_ARCH_MEMSCAN |
194 | extern void * memscan(void *,int,__kernel_size_t); |
195 | #endif |
196 | #ifndef __HAVE_ARCH_MEMCMP |
197 | extern int memcmp(const void *,const void *,__kernel_size_t); |
198 | #endif |
199 | #ifndef __HAVE_ARCH_BCMP |
200 | extern int bcmp(const void *,const void *,__kernel_size_t); |
201 | #endif |
202 | #ifndef __HAVE_ARCH_MEMCHR |
203 | extern void * memchr(const void *,int,__kernel_size_t); |
204 | #endif |
205 | #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE |
206 | static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) |
207 | { |
208 | memcpy(dst, src, cnt); |
209 | } |
210 | #endif |
211 | |
212 | void *memchr_inv(const void *s, int c, size_t n); |
213 | char *strreplace(char *str, char old, char new); |
214 | |
215 | extern void kfree_const(const void *x); |
216 | |
217 | extern char *kstrdup(const char *s, gfp_t gfp) __malloc; |
218 | extern const char *kstrdup_const(const char *s, gfp_t gfp); |
219 | extern char *kstrndup(const char *s, size_t len, gfp_t gfp); |
220 | extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); |
221 | extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); |
222 | extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); |
223 | |
224 | extern char **argv_split(gfp_t gfp, const char *str, int *argcp); |
225 | extern void argv_free(char **argv); |
226 | |
227 | extern bool sysfs_streq(const char *s1, const char *s2); |
228 | int match_string(const char * const *array, size_t n, const char *string); |
229 | int __sysfs_match_string(const char * const *array, size_t n, const char *s); |
230 | |
231 | /** |
232 | * sysfs_match_string - matches given string in an array |
233 | * @_a: array of strings |
234 | * @_s: string to match with |
235 | * |
236 | * Helper for __sysfs_match_string(). Calculates the size of @a automatically. |
237 | */ |
238 | #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) |
239 | |
240 | #ifdef CONFIG_BINARY_PRINTF |
241 | int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); |
242 | int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); |
243 | int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); |
244 | #endif |
245 | |
246 | extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, |
247 | const void *from, size_t available); |
248 | |
249 | int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); |
250 | |
251 | /** |
252 | * strstarts - does @str start with @prefix? |
253 | * @str: string to examine |
254 | * @prefix: prefix to look for. |
255 | */ |
256 | static inline bool strstarts(const char *str, const char *prefix) |
257 | { |
258 | return strncmp(str, prefix, strlen(prefix)) == 0; |
259 | } |
260 | |
261 | size_t memweight(const void *ptr, size_t bytes); |
262 | |
263 | /** |
264 | * memzero_explicit - Fill a region of memory (e.g. sensitive |
265 | * keying data) with 0s. |
266 | * @s: Pointer to the start of the area. |
267 | * @count: The size of the area. |
268 | * |
269 | * Note: usually using memset() is just fine (!), but in cases |
270 | * where clearing out _local_ data at the end of a scope is |
271 | * necessary, memzero_explicit() should be used instead in |
272 | * order to prevent the compiler from optimising away zeroing. |
273 | * |
274 | * memzero_explicit() doesn't need an arch-specific version as |
275 | * it just invokes the one of memset() implicitly. |
276 | */ |
277 | static inline void memzero_explicit(void *s, size_t count) |
278 | { |
279 | memset(s, c: 0, n: count); |
280 | barrier_data(s); |
281 | } |
282 | |
283 | /** |
284 | * kbasename - return the last part of a pathname. |
285 | * |
286 | * @path: path to extract the filename from. |
287 | */ |
288 | static inline const char *kbasename(const char *path) |
289 | { |
290 | const char *tail = strrchr(path, '/'); |
291 | return tail ? tail + 1 : path; |
292 | } |
293 | |
294 | #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) |
295 | #include <linux/fortify-string.h> |
296 | #endif |
297 | #ifndef unsafe_memcpy |
298 | #define unsafe_memcpy(dst, src, bytes, justification) \ |
299 | memcpy(dst, src, bytes) |
300 | #endif |
301 | |
302 | void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, |
303 | int pad); |
304 | |
305 | /** |
306 | * strtomem_pad - Copy NUL-terminated string to non-NUL-terminated buffer |
307 | * |
308 | * @dest: Pointer of destination character array (marked as __nonstring) |
309 | * @src: Pointer to NUL-terminated string |
310 | * @pad: Padding character to fill any remaining bytes of @dest after copy |
311 | * |
312 | * This is a replacement for strncpy() uses where the destination is not |
313 | * a NUL-terminated string, but with bounds checking on the source size, and |
314 | * an explicit padding character. If padding is not required, use strtomem(). |
315 | * |
316 | * Note that the size of @dest is not an argument, as the length of @dest |
317 | * must be discoverable by the compiler. |
318 | */ |
319 | #define strtomem_pad(dest, src, pad) do { \ |
320 | const size_t _dest_len = __builtin_object_size(dest, 1); \ |
321 | const size_t _src_len = __builtin_object_size(src, 1); \ |
322 | \ |
323 | BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ |
324 | _dest_len == (size_t)-1); \ |
325 | memcpy_and_pad(dest, _dest_len, src, \ |
326 | strnlen(src, min(_src_len, _dest_len)), pad); \ |
327 | } while (0) |
328 | |
329 | /** |
330 | * strtomem - Copy NUL-terminated string to non-NUL-terminated buffer |
331 | * |
332 | * @dest: Pointer of destination character array (marked as __nonstring) |
333 | * @src: Pointer to NUL-terminated string |
334 | * |
335 | * This is a replacement for strncpy() uses where the destination is not |
336 | * a NUL-terminated string, but with bounds checking on the source size, and |
337 | * without trailing padding. If padding is required, use strtomem_pad(). |
338 | * |
339 | * Note that the size of @dest is not an argument, as the length of @dest |
340 | * must be discoverable by the compiler. |
341 | */ |
342 | #define strtomem(dest, src) do { \ |
343 | const size_t _dest_len = __builtin_object_size(dest, 1); \ |
344 | const size_t _src_len = __builtin_object_size(src, 1); \ |
345 | \ |
346 | BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ |
347 | _dest_len == (size_t)-1); \ |
348 | memcpy(dest, src, strnlen(src, min(_src_len, _dest_len))); \ |
349 | } while (0) |
350 | |
351 | /** |
352 | * memset_after - Set a value after a struct member to the end of a struct |
353 | * |
354 | * @obj: Address of target struct instance |
355 | * @v: Byte value to repeatedly write |
356 | * @member: after which struct member to start writing bytes |
357 | * |
358 | * This is good for clearing padding following the given member. |
359 | */ |
360 | #define memset_after(obj, v, member) \ |
361 | ({ \ |
362 | u8 *__ptr = (u8 *)(obj); \ |
363 | typeof(v) __val = (v); \ |
364 | memset(__ptr + offsetofend(typeof(*(obj)), member), __val, \ |
365 | sizeof(*(obj)) - offsetofend(typeof(*(obj)), member)); \ |
366 | }) |
367 | |
368 | /** |
369 | * memset_startat - Set a value starting at a member to the end of a struct |
370 | * |
371 | * @obj: Address of target struct instance |
372 | * @v: Byte value to repeatedly write |
373 | * @member: struct member to start writing at |
374 | * |
375 | * Note that if there is padding between the prior member and the target |
376 | * member, memset_after() should be used to clear the prior padding. |
377 | */ |
378 | #define memset_startat(obj, v, member) \ |
379 | ({ \ |
380 | u8 *__ptr = (u8 *)(obj); \ |
381 | typeof(v) __val = (v); \ |
382 | memset(__ptr + offsetof(typeof(*(obj)), member), __val, \ |
383 | sizeof(*(obj)) - offsetof(typeof(*(obj)), member)); \ |
384 | }) |
385 | |
386 | /** |
387 | * str_has_prefix - Test if a string has a given prefix |
388 | * @str: The string to test |
389 | * @prefix: The string to see if @str starts with |
390 | * |
391 | * A common way to test a prefix of a string is to do: |
392 | * strncmp(str, prefix, sizeof(prefix) - 1) |
393 | * |
394 | * But this can lead to bugs due to typos, or if prefix is a pointer |
395 | * and not a constant. Instead use str_has_prefix(). |
396 | * |
397 | * Returns: |
398 | * * strlen(@prefix) if @str starts with @prefix |
399 | * * 0 if @str does not start with @prefix |
400 | */ |
401 | static __always_inline size_t str_has_prefix(const char *str, const char *prefix) |
402 | { |
403 | size_t len = strlen(prefix); |
404 | return strncmp(str, prefix, len) == 0 ? len : 0; |
405 | } |
406 | |
407 | #endif /* _LINUX_STRING_H_ */ |
408 | |