| 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 | 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 | memset(s, 0, count); |
| 239 | 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 | const char *tail = strrchr(path, '/'); |
| 250 | 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 | size_t len = strlen(prefix); |
| 360 | return strncmp(str, prefix, len) == 0 ? len : 0; |
| 361 | } |
| 362 | |
| 363 | #endif /* _LINUX_STRING_H_ */ |