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      1 /*	$NetBSD: string.h,v 1.11 2021/12/19 11:45:01 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _LINUX_STRING_H_
     33 #define _LINUX_STRING_H_
     34 
     35 #include <sys/types.h>
     36 #include <sys/cdefs.h>
     37 #include <sys/errno.h>
     38 #include <sys/null.h>
     39 
     40 #include <linux/slab.h>
     41 
     42 static inline void *
     43 memchr_inv(const void *buffer, int c, size_t len)
     44 {
     45 	const uint8_t byte = c;	/* XXX lose */
     46 	const char *p;
     47 
     48 	for (p = buffer; len-- > 0; p++)
     49 		if (*p != byte)
     50 			return __UNCONST(p);
     51 
     52 	return NULL;
     53 }
     54 
     55 static inline void *
     56 kmemdup(const void *src, size_t len, gfp_t gfp)
     57 {
     58 	void *dst;
     59 
     60 	dst = kmalloc(len, gfp);
     61 	if (dst == NULL)
     62 		return NULL;
     63 
     64 	(void)memcpy(dst, src, len);
     65 	return dst;
     66 }
     67 
     68 static inline char *
     69 kstrndup(const char *src, size_t maxlen, gfp_t gfp)
     70 {
     71 	char *dst;
     72 	size_t len;
     73 
     74 	if (src == NULL)
     75 		return NULL;
     76 
     77 	len = strnlen(src, maxlen);
     78 	dst = kmalloc(len + 1, gfp);
     79 	if (dst == NULL)
     80 		return NULL;
     81 
     82 	(void)memcpy(dst, src, len);
     83 	dst[len] = '\0';
     84 
     85 	return dst;
     86 }
     87 
     88 static inline char *
     89 kstrdup(const char *src, gfp_t gfp)
     90 {
     91 
     92 	if (src == NULL)
     93 		return NULL;
     94 	return kstrndup(src, strlen(src), gfp);
     95 }
     96 
     97 static inline ssize_t
     98 strscpy(char *dst, const char *src, size_t dstsize)
     99 {
    100 	size_t n = dstsize;
    101 
    102 	/* If no space for a NUL terminator, fail.  */
    103 	if (n == 0)
    104 		return -E2BIG;
    105 
    106 	/* Copy until we get a NUL terminator or the end of the buffer.  */
    107 	while ((*dst++ = *src++) != '\0') {
    108 		if (__predict_false(--n == 0)) {
    109 			dst[-1] = '\0'; /* NUL-terminate */
    110 			return -E2BIG;
    111 		}
    112 	}
    113 
    114 	/* Return the number of bytes copied, excluding NUL.  */
    115 	return dstsize - n;
    116 }
    117 
    118 static inline void *
    119 memset32(uint32_t *buf, uint32_t v, size_t n)
    120 {
    121 	uint32_t *p = buf;
    122 
    123 	while (n --> 0)
    124 		*p++ = v;
    125 
    126 	return buf;
    127 }
    128 
    129 static inline void *
    130 memset64(uint64_t *buf, uint64_t v, size_t n)
    131 {
    132 	uint64_t *p = buf;
    133 
    134 	while (n --> 0)
    135 		*p++ = v;
    136 
    137 	return buf;
    138 }
    139 
    140 static inline void *
    141 memset_p(void **buf, void *v, size_t n)
    142 {
    143 	void **p = buf;
    144 
    145 	while (n --> 0)
    146 		*p++ = v;
    147 
    148 	return buf;
    149 }
    150 
    151 #define str_has_prefix(str, prefix) strncmp(str, prefix, strlen(prefix))
    152 
    153 static inline int
    154 match_string(const char *const *haystack, size_t n, const char *needle)
    155 {
    156 	int i;
    157 
    158 	for (i = 0; i < n; i++) {
    159 		if (haystack[i] == NULL)
    160 			break;
    161 		if (strcmp(haystack[i], needle) == 0)
    162 			return i;
    163 		if (i == INT_MAX)
    164 			break;
    165 	}
    166 	return -EINVAL;
    167 }
    168 
    169 #endif  /* _LINUX_STRING_H_ */
    170