/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_STRING_H_ #define _LINUX_STRING_H_ #include #include #include /* for inline */ #include /* for size_t */ #include /* for NULL */ #include /* for ERR_PTR() */ #include /* for E2BIG */ #include /* for check_mul_overflow() */ #include #include extern char *strndup_user(const char __user *, long); extern void *memdup_user(const void __user *, size_t); extern void *vmemdup_user(const void __user *, size_t); extern void *memdup_user_nul(const void __user *, size_t); /** * memdup_array_user - duplicate array from user space * @src: source address in user space * @n: number of array members to copy * @size: size of one array member * * Return: an ERR_PTR() on failure. Result is physically * contiguous, to be freed by kfree(). */ static inline void *memdup_array_user(const void __user *src, size_t n, size_t size) { size_t nbytes; if (check_mul_overflow(n, size, &nbytes)) return ERR_PTR(-EOVERFLOW); return memdup_user(src, nbytes); } /** * vmemdup_array_user - duplicate array from user space * @src: source address in user space * @n: number of array members to copy * @size: size of one array member * * Return: an ERR_PTR() on failure. Result may be not * physically contiguous. Use kvfree() to free. */ static inline void *vmemdup_array_user(const void __user *src, size_t n, size_t size) { size_t nbytes; if (check_mul_overflow(n, size, &nbytes)) return ERR_PTR(-EOVERFLOW); return vmemdup_user(src, nbytes); } /* * Include machine specific inline routines */ #include #ifndef __HAVE_ARCH_STRCPY extern char * strcpy(char *,const char *); #endif #ifndef __HAVE_ARCH_STRNCPY extern char * strncpy(char *,const char *, __kernel_size_t); #endif ssize_t sized_strscpy(char *, const char *, size_t); /* * The 2 argument style can only be used when dst is an array with a * known size. */ #define __strscpy0(dst, src, ...) \ sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst)) #define __strscpy1(dst, src, size) sized_strscpy(dst, src, size) #define __strscpy_pad0(dst, src, ...) \ sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst)) #define __strscpy_pad1(dst, src, size) sized_strscpy_pad(dst, src, size) /** * strscpy - Copy a C-string into a sized buffer * @dst: Where to copy the string to * @src: Where to copy the string from * @...: Size of destination buffer (optional) * * Copy the source string @src, or as much of it as fits, into the * destination @dst buffer. The behavior is undefined if the string * buffers overlap. The destination @dst buffer is always NUL terminated, * unless it's zero-sized. * * The size argument @... is only required when @dst is not an array, or * when the copy needs to be smaller than sizeof(@dst). * * Preferred to strncpy() since it always returns a valid string, and * doesn't unnecessarily force the tail of the destination buffer to be * zero padded. If padding is desired please use strscpy_pad(). * * Returns the number of characters copied in @dst (not including the * trailing %NUL) or -E2BIG if @size is 0 or the copy from @src was * truncated. */ #define strscpy(dst, src, ...) \ CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) #define sized_strscpy_pad(dest, src, count) ({ \ char *__dst = (dest); \ const char *__src = (src); \ const size_t __count = (count); \ ssize_t __wrote; \ \ __wrote = sized_strscpy(__dst, __src, __count); \ if (__wrote >= 0 && __wrote < __count) \ memset(__dst + __wrote + 1, 0, __count - __wrote - 1); \ __wrote; \ }) /** * strscpy_pad() - Copy a C-string into a sized buffer * @dst: Where to copy the string to * @src: Where to copy the string from * @...: Size of destination buffer * * Copy the string, or as much of it as fits, into the dest buffer. The * behavior is undefined if the string buffers overlap. The destination * buffer is always %NUL terminated, unless it's zero-sized. * * If the source string is shorter than the destination buffer, the * remaining bytes in the buffer will be filled with %NUL bytes. * * For full explanation of why you may want to consider using the * 'strscpy' functions please see the function docstring for strscpy(). * * Returns: * * The number of characters copied (not including the trailing %NULs) * * -E2BIG if count is 0 or @src was truncated. */ #define strscpy_pad(dst, src, ...) \ CONCATENATE(__strscpy_pad, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) #ifndef __HAVE_ARCH_STRCAT extern char * strcat(char *, const char *); #endif #ifndef __HAVE_ARCH_STRNCAT extern char * strncat(char *, const char *, __kernel_size_t); #endif #ifndef __HAVE_ARCH_STRLCAT extern size_t strlcat(char *, const char *, __kernel_size_t); #endif #ifndef __HAVE_ARCH_STRCMP extern int strcmp(const char *,const char *); #endif #ifndef __HAVE_ARCH_STRNCMP extern int strncmp(const char *,const char *,__kernel_size_t); #endif #ifndef __HAVE_ARCH_STRCASECMP extern int strcasecmp(const char *s1, const char *s2); #endif #ifndef __HAVE_ARCH_STRNCASECMP extern int strncasecmp(const char *s1, const char *s2, size_t n); #endif #ifndef __HAVE_ARCH_STRCHR extern char * strchr(const char *,int); #endif #ifndef __HAVE_ARCH_STRCHRNUL extern char * strchrnul(const char *,int); #endif extern char * strnchrnul(const char *, size_t, int); #ifndef __HAVE_ARCH_STRNCHR extern char * strnchr(const char *, size_t, int); #endif #ifndef __HAVE_ARCH_STRRCHR extern char * strrchr(const char *,int); #endif extern char * __must_check skip_spaces(const char *); extern char *strim(char *); static inline __must_check char *strstrip(char *str) { return strim(str); } #ifndef __HAVE_ARCH_STRSTR extern char * strstr(const char *, const char *); #endif #ifndef __HAVE_ARCH_STRNSTR extern char * strnstr(const char *, const char *, size_t); #endif #ifndef __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); #endif #ifndef __HAVE_ARCH_STRNLEN extern __kernel_size_t strnlen(const char *,__kernel_size_t); #endif #ifndef __HAVE_ARCH_STRPBRK extern char * strpbrk(const char *,const char *); #endif #ifndef __HAVE_ARCH_STRSEP extern char * strsep(char **,const char *); #endif #ifndef __HAVE_ARCH_STRSPN extern __kernel_size_t strspn(const char *,const char *); #endif #ifndef __HAVE_ARCH_STRCSPN extern __kernel_size_t strcspn(const char *,const char *); #endif #ifndef __HAVE_ARCH_MEMSET extern void * memset(void *,int,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMSET16 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMSET32 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMSET64 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); #endif static inline void *memset_l(unsigned long *p, unsigned long v, __kernel_size_t n) { if (BITS_PER_LONG == 32) return memset32((uint32_t *)p, v, n); else return memset64((uint64_t *)p, v, n); } static inline void *memset_p(void **p, void *v, __kernel_size_t n) { if (BITS_PER_LONG == 32) return memset32((uint32_t *)p, (uintptr_t)v, n); else return memset64((uint64_t *)p, (uintptr_t)v, n); } extern void **__memcat_p(void **a, void **b); #define memcat_p(a, b) ({ \ BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \ "type mismatch in memcat_p()"); \ (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \ }) #ifndef __HAVE_ARCH_MEMCPY extern void * memcpy(void *,const void *,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMMOVE extern void * memmove(void *,const void *,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMSCAN extern void * memscan(void *,int,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMCMP extern int memcmp(const void *,const void *,__kernel_size_t); #endif #ifndef __HAVE_ARCH_BCMP extern int bcmp(const void *,const void *,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMCHR extern void * memchr(const void *,int,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) { memcpy(dst, src, cnt); } #endif void *memchr_inv(const void *s, int c, size_t n); char *strreplace(char *str, char old, char new); extern void kfree_const(const void *x); extern char *kstrdup(const char *s, gfp_t gfp) __malloc; extern const char *kstrdup_const(const char *s, gfp_t gfp); extern char *kstrndup(const char *s, size_t len, gfp_t gfp); extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2); extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); extern void *kmemdup_array(const void *src, size_t element_size, size_t count, gfp_t gfp); /* lib/argv_split.c */ extern char **argv_split(gfp_t gfp, const char *str, int *argcp); extern void argv_free(char **argv); /* lib/cmdline.c */ extern int get_option(char **str, int *pint); extern char *get_options(const char *str, int nints, int *ints); extern unsigned long long memparse(const char *ptr, char **retptr); extern bool parse_option_str(const char *str, const char *option); extern char *next_arg(char *args, char **param, char **val); extern bool sysfs_streq(const char *s1, const char *s2); int match_string(const char * const *array, size_t n, const char *string); int __sysfs_match_string(const char * const *array, size_t n, const char *s); /** * sysfs_match_string - matches given string in an array * @_a: array of strings * @_s: string to match with * * Helper for __sysfs_match_string(). Calculates the size of @a automatically. */ #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) #ifdef CONFIG_BINARY_PRINTF int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); #endif extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, const void *from, size_t available); int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); /** * strstarts - does @str start with @prefix? * @str: string to examine * @prefix: prefix to look for. */ static inline bool strstarts(const char *str, const char *prefix) { return strncmp(str, prefix, strlen(prefix)) == 0; } size_t memweight(const void *ptr, size_t bytes); /** * memzero_explicit - Fill a region of memory (e.g. sensitive * keying data) with 0s. * @s: Pointer to the start of the area. * @count: The size of the area. * * Note: usually using memset() is just fine (!), but in cases * where clearing out _local_ data at the end of a scope is * necessary, memzero_explicit() should be used instead in * order to prevent the compiler from optimising away zeroing. * * memzero_explicit() doesn't need an arch-specific version as * it just invokes the one of memset() implicitly. */ static inline void memzero_explicit(void *s, size_t count) { memset(s, 0, count); barrier_data(s); } /** * kbasename - return the last part of a pathname. * * @path: path to extract the filename from. */ static inline const char *kbasename(const char *path) { const char *tail = strrchr(path, '/'); return tail ? tail + 1 : path; } #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) #include #endif #ifndef unsafe_memcpy #define unsafe_memcpy(dst, src, bytes, justification) \ memcpy(dst, src, bytes) #endif void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, int pad); /** * strtomem_pad - Copy NUL-terminated string to non-NUL-terminated buffer * * @dest: Pointer of destination character array (marked as __nonstring) * @src: Pointer to NUL-terminated string * @pad: Padding character to fill any remaining bytes of @dest after copy * * This is a replacement for strncpy() uses where the destination is not * a NUL-terminated string, but with bounds checking on the source size, and * an explicit padding character. If padding is not required, use strtomem(). * * Note that the size of @dest is not an argument, as the length of @dest * must be discoverable by the compiler. */ #define strtomem_pad(dest, src, pad) do { \ const size_t _dest_len = __builtin_object_size(dest, 1); \ const size_t _src_len = __builtin_object_size(src, 1); \ \ BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ _dest_len == (size_t)-1); \ memcpy_and_pad(dest, _dest_len, src, \ strnlen(src, min(_src_len, _dest_len)), pad); \ } while (0) /** * strtomem - Copy NUL-terminated string to non-NUL-terminated buffer * * @dest: Pointer of destination character array (marked as __nonstring) * @src: Pointer to NUL-terminated string * * This is a replacement for strncpy() uses where the destination is not * a NUL-terminated string, but with bounds checking on the source size, and * without trailing padding. If padding is required, use strtomem_pad(). * * Note that the size of @dest is not an argument, as the length of @dest * must be discoverable by the compiler. */ #define strtomem(dest, src) do { \ const size_t _dest_len = __builtin_object_size(dest, 1); \ const size_t _src_len = __builtin_object_size(src, 1); \ \ BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ _dest_len == (size_t)-1); \ memcpy(dest, src, strnlen(src, min(_src_len, _dest_len))); \ } while (0) /** * memset_after - Set a value after a struct member to the end of a struct * * @obj: Address of target struct instance * @v: Byte value to repeatedly write * @member: after which struct member to start writing bytes * * This is good for clearing padding following the given member. */ #define memset_after(obj, v, member) \ ({ \ u8 *__ptr = (u8 *)(obj); \ typeof(v) __val = (v); \ memset(__ptr + offsetofend(typeof(*(obj)), member), __val, \ sizeof(*(obj)) - offsetofend(typeof(*(obj)), member)); \ }) /** * memset_startat - Set a value starting at a member to the end of a struct * * @obj: Address of target struct instance * @v: Byte value to repeatedly write * @member: struct member to start writing at * * Note that if there is padding between the prior member and the target * member, memset_after() should be used to clear the prior padding. */ #define memset_startat(obj, v, member) \ ({ \ u8 *__ptr = (u8 *)(obj); \ typeof(v) __val = (v); \ memset(__ptr + offsetof(typeof(*(obj)), member), __val, \ sizeof(*(obj)) - offsetof(typeof(*(obj)), member)); \ }) /** * str_has_prefix - Test if a string has a given prefix * @str: The string to test * @prefix: The string to see if @str starts with * * A common way to test a prefix of a string is to do: * strncmp(str, prefix, sizeof(prefix) - 1) * * But this can lead to bugs due to typos, or if prefix is a pointer * and not a constant. Instead use str_has_prefix(). * * Returns: * * strlen(@prefix) if @str starts with @prefix * * 0 if @str does not start with @prefix */ static __always_inline size_t str_has_prefix(const char *str, const char *prefix) { size_t len = strlen(prefix); return strncmp(str, prefix, len) == 0 ? len : 0; } #endif /* _LINUX_STRING_H_ */