Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_STRING_H_
3 : #define _LINUX_STRING_H_
4 :
5 : #include <linux/compiler.h> /* for inline */
6 : #include <linux/types.h> /* for size_t */
7 : #include <linux/stddef.h> /* for NULL */
8 : #include <linux/errno.h> /* for E2BIG */
9 : #include <linux/stdarg.h>
10 : #include <uapi/linux/string.h>
11 :
12 : extern char *strndup_user(const char __user *, long);
13 : extern void *memdup_user(const void __user *, size_t);
14 : extern void *vmemdup_user(const void __user *, size_t);
15 : extern void *memdup_user_nul(const void __user *, size_t);
16 :
17 : /*
18 : * Include machine specific inline routines
19 : */
20 : #include <asm/string.h>
21 :
22 : #ifndef __HAVE_ARCH_STRCPY
23 : extern char * strcpy(char *,const char *);
24 : #endif
25 : #ifndef __HAVE_ARCH_STRNCPY
26 : extern char * strncpy(char *,const char *, __kernel_size_t);
27 : #endif
28 : #ifndef __HAVE_ARCH_STRLCPY
29 : size_t strlcpy(char *, const char *, size_t);
30 : #endif
31 : #ifndef __HAVE_ARCH_STRSCPY
32 : ssize_t strscpy(char *, const char *, size_t);
33 : #endif
34 :
35 : /* Wraps calls to strscpy()/memset(), no arch specific code required */
36 : ssize_t strscpy_pad(char *dest, const char *src, size_t count);
37 :
38 : #ifndef __HAVE_ARCH_STRCAT
39 : extern char * strcat(char *, const char *);
40 : #endif
41 : #ifndef __HAVE_ARCH_STRNCAT
42 : extern char * strncat(char *, const char *, __kernel_size_t);
43 : #endif
44 : #ifndef __HAVE_ARCH_STRLCAT
45 : extern size_t strlcat(char *, const char *, __kernel_size_t);
46 : #endif
47 : #ifndef __HAVE_ARCH_STRCMP
48 : extern int strcmp(const char *,const char *);
49 : #endif
50 : #ifndef __HAVE_ARCH_STRNCMP
51 : extern int strncmp(const char *,const char *,__kernel_size_t);
52 : #endif
53 : #ifndef __HAVE_ARCH_STRCASECMP
54 : extern int strcasecmp(const char *s1, const char *s2);
55 : #endif
56 : #ifndef __HAVE_ARCH_STRNCASECMP
57 : extern int strncasecmp(const char *s1, const char *s2, size_t n);
58 : #endif
59 : #ifndef __HAVE_ARCH_STRCHR
60 : extern char * strchr(const char *,int);
61 : #endif
62 : #ifndef __HAVE_ARCH_STRCHRNUL
63 : extern char * strchrnul(const char *,int);
64 : #endif
65 : extern char * strnchrnul(const char *, size_t, int);
66 : #ifndef __HAVE_ARCH_STRNCHR
67 : extern char * strnchr(const char *, size_t, int);
68 : #endif
69 : #ifndef __HAVE_ARCH_STRRCHR
70 : extern char * strrchr(const char *,int);
71 : #endif
72 : extern char * __must_check skip_spaces(const char *);
73 :
74 : extern char *strim(char *);
75 :
76 : static inline __must_check char *strstrip(char *str)
77 : {
78 0 : return strim(str);
79 : }
80 :
81 : #ifndef __HAVE_ARCH_STRSTR
82 : extern char * strstr(const char *, const char *);
83 : #endif
84 : #ifndef __HAVE_ARCH_STRNSTR
85 : extern char * strnstr(const char *, const char *, size_t);
86 : #endif
87 : #ifndef __HAVE_ARCH_STRLEN
88 : extern __kernel_size_t strlen(const char *);
89 : #endif
90 : #ifndef __HAVE_ARCH_STRNLEN
91 : extern __kernel_size_t strnlen(const char *,__kernel_size_t);
92 : #endif
93 : #ifndef __HAVE_ARCH_STRPBRK
94 : extern char * strpbrk(const char *,const char *);
95 : #endif
96 : #ifndef __HAVE_ARCH_STRSEP
97 : extern char * strsep(char **,const char *);
98 : #endif
99 : #ifndef __HAVE_ARCH_STRSPN
100 : extern __kernel_size_t strspn(const char *,const char *);
101 : #endif
102 : #ifndef __HAVE_ARCH_STRCSPN
103 : extern __kernel_size_t strcspn(const char *,const char *);
104 : #endif
105 :
106 : #ifndef __HAVE_ARCH_MEMSET
107 : extern void * memset(void *,int,__kernel_size_t);
108 : #endif
109 :
110 : #ifndef __HAVE_ARCH_MEMSET16
111 : extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
112 : #endif
113 :
114 : #ifndef __HAVE_ARCH_MEMSET32
115 : extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
116 : #endif
117 :
118 : #ifndef __HAVE_ARCH_MEMSET64
119 : extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
120 : #endif
121 :
122 : static inline void *memset_l(unsigned long *p, unsigned long v,
123 : __kernel_size_t n)
124 : {
125 : if (BITS_PER_LONG == 32)
126 : return memset32((uint32_t *)p, v, n);
127 : else
128 : return memset64((uint64_t *)p, v, n);
129 : }
130 :
131 : static inline void *memset_p(void **p, void *v, __kernel_size_t n)
132 : {
133 : if (BITS_PER_LONG == 32)
134 : return memset32((uint32_t *)p, (uintptr_t)v, n);
135 : else
136 : return memset64((uint64_t *)p, (uintptr_t)v, n);
137 : }
138 :
139 : extern void **__memcat_p(void **a, void **b);
140 : #define memcat_p(a, b) ({ \
141 : BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \
142 : "type mismatch in memcat_p()"); \
143 : (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \
144 : })
145 :
146 : #ifndef __HAVE_ARCH_MEMCPY
147 : extern void * memcpy(void *,const void *,__kernel_size_t);
148 : #endif
149 : #ifndef __HAVE_ARCH_MEMMOVE
150 : extern void * memmove(void *,const void *,__kernel_size_t);
151 : #endif
152 : #ifndef __HAVE_ARCH_MEMSCAN
153 : extern void * memscan(void *,int,__kernel_size_t);
154 : #endif
155 : #ifndef __HAVE_ARCH_MEMCMP
156 : extern int memcmp(const void *,const void *,__kernel_size_t);
157 : #endif
158 : #ifndef __HAVE_ARCH_BCMP
159 : extern int bcmp(const void *,const void *,__kernel_size_t);
160 : #endif
161 : #ifndef __HAVE_ARCH_MEMCHR
162 : extern void * memchr(const void *,int,__kernel_size_t);
163 : #endif
164 : #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
165 : static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
166 : {
167 : memcpy(dst, src, cnt);
168 : }
169 : #endif
170 :
171 : void *memchr_inv(const void *s, int c, size_t n);
172 : char *strreplace(char *s, char old, char new);
173 :
174 : extern void kfree_const(const void *x);
175 :
176 : extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
177 : extern const char *kstrdup_const(const char *s, gfp_t gfp);
178 : extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
179 : extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
180 : extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
181 : extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
182 :
183 : extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
184 : extern void argv_free(char **argv);
185 :
186 : extern bool sysfs_streq(const char *s1, const char *s2);
187 : int match_string(const char * const *array, size_t n, const char *string);
188 : int __sysfs_match_string(const char * const *array, size_t n, const char *s);
189 :
190 : /**
191 : * sysfs_match_string - matches given string in an array
192 : * @_a: array of strings
193 : * @_s: string to match with
194 : *
195 : * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
196 : */
197 : #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
198 :
199 : #ifdef CONFIG_BINARY_PRINTF
200 : int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
201 : int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
202 : int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
203 : #endif
204 :
205 : extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
206 : const void *from, size_t available);
207 :
208 : int ptr_to_hashval(const void *ptr, unsigned long *hashval_out);
209 :
210 : /**
211 : * strstarts - does @str start with @prefix?
212 : * @str: string to examine
213 : * @prefix: prefix to look for.
214 : */
215 : static inline bool strstarts(const char *str, const char *prefix)
216 : {
217 : return strncmp(str, prefix, strlen(prefix)) == 0;
218 : }
219 :
220 : size_t memweight(const void *ptr, size_t bytes);
221 :
222 : /**
223 : * memzero_explicit - Fill a region of memory (e.g. sensitive
224 : * keying data) with 0s.
225 : * @s: Pointer to the start of the area.
226 : * @count: The size of the area.
227 : *
228 : * Note: usually using memset() is just fine (!), but in cases
229 : * where clearing out _local_ data at the end of a scope is
230 : * necessary, memzero_explicit() should be used instead in
231 : * order to prevent the compiler from optimising away zeroing.
232 : *
233 : * memzero_explicit() doesn't need an arch-specific version as
234 : * it just invokes the one of memset() implicitly.
235 : */
236 : static inline void memzero_explicit(void *s, size_t count)
237 : {
238 828 : memset(s, 0, count);
239 828 : barrier_data(s);
240 : }
241 :
242 : /**
243 : * kbasename - return the last part of a pathname.
244 : *
245 : * @path: path to extract the filename from.
246 : */
247 : static inline const char *kbasename(const char *path)
248 : {
249 0 : const char *tail = strrchr(path, '/');
250 0 : return tail ? tail + 1 : path;
251 : }
252 :
253 : #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
254 : #include <linux/fortify-string.h>
255 : #endif
256 : #ifndef unsafe_memcpy
257 : #define unsafe_memcpy(dst, src, bytes, justification) \
258 : memcpy(dst, src, bytes)
259 : #endif
260 :
261 : void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
262 : int pad);
263 :
264 : /**
265 : * strtomem_pad - Copy NUL-terminated string to non-NUL-terminated buffer
266 : *
267 : * @dest: Pointer of destination character array (marked as __nonstring)
268 : * @src: Pointer to NUL-terminated string
269 : * @pad: Padding character to fill any remaining bytes of @dest after copy
270 : *
271 : * This is a replacement for strncpy() uses where the destination is not
272 : * a NUL-terminated string, but with bounds checking on the source size, and
273 : * an explicit padding character. If padding is not required, use strtomem().
274 : *
275 : * Note that the size of @dest is not an argument, as the length of @dest
276 : * must be discoverable by the compiler.
277 : */
278 : #define strtomem_pad(dest, src, pad) do { \
279 : const size_t _dest_len = __builtin_object_size(dest, 1); \
280 : \
281 : BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \
282 : _dest_len == (size_t)-1); \
283 : memcpy_and_pad(dest, _dest_len, src, strnlen(src, _dest_len), pad); \
284 : } while (0)
285 :
286 : /**
287 : * strtomem - Copy NUL-terminated string to non-NUL-terminated buffer
288 : *
289 : * @dest: Pointer of destination character array (marked as __nonstring)
290 : * @src: Pointer to NUL-terminated string
291 : *
292 : * This is a replacement for strncpy() uses where the destination is not
293 : * a NUL-terminated string, but with bounds checking on the source size, and
294 : * without trailing padding. If padding is required, use strtomem_pad().
295 : *
296 : * Note that the size of @dest is not an argument, as the length of @dest
297 : * must be discoverable by the compiler.
298 : */
299 : #define strtomem(dest, src) do { \
300 : const size_t _dest_len = __builtin_object_size(dest, 1); \
301 : \
302 : BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \
303 : _dest_len == (size_t)-1); \
304 : memcpy(dest, src, min(_dest_len, strnlen(src, _dest_len))); \
305 : } while (0)
306 :
307 : /**
308 : * memset_after - Set a value after a struct member to the end of a struct
309 : *
310 : * @obj: Address of target struct instance
311 : * @v: Byte value to repeatedly write
312 : * @member: after which struct member to start writing bytes
313 : *
314 : * This is good for clearing padding following the given member.
315 : */
316 : #define memset_after(obj, v, member) \
317 : ({ \
318 : u8 *__ptr = (u8 *)(obj); \
319 : typeof(v) __val = (v); \
320 : memset(__ptr + offsetofend(typeof(*(obj)), member), __val, \
321 : sizeof(*(obj)) - offsetofend(typeof(*(obj)), member)); \
322 : })
323 :
324 : /**
325 : * memset_startat - Set a value starting at a member to the end of a struct
326 : *
327 : * @obj: Address of target struct instance
328 : * @v: Byte value to repeatedly write
329 : * @member: struct member to start writing at
330 : *
331 : * Note that if there is padding between the prior member and the target
332 : * member, memset_after() should be used to clear the prior padding.
333 : */
334 : #define memset_startat(obj, v, member) \
335 : ({ \
336 : u8 *__ptr = (u8 *)(obj); \
337 : typeof(v) __val = (v); \
338 : memset(__ptr + offsetof(typeof(*(obj)), member), __val, \
339 : sizeof(*(obj)) - offsetof(typeof(*(obj)), member)); \
340 : })
341 :
342 : /**
343 : * str_has_prefix - Test if a string has a given prefix
344 : * @str: The string to test
345 : * @prefix: The string to see if @str starts with
346 : *
347 : * A common way to test a prefix of a string is to do:
348 : * strncmp(str, prefix, sizeof(prefix) - 1)
349 : *
350 : * But this can lead to bugs due to typos, or if prefix is a pointer
351 : * and not a constant. Instead use str_has_prefix().
352 : *
353 : * Returns:
354 : * * strlen(@prefix) if @str starts with @prefix
355 : * * 0 if @str does not start with @prefix
356 : */
357 : static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
358 : {
359 30 : size_t len = strlen(prefix);
360 30 : return strncmp(str, prefix, len) == 0 ? len : 0;
361 : }
362 :
363 : #endif /* _LINUX_STRING_H_ */
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