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wdenkc6097192002-11-03 00:24:07 +00001/*
2 * linux/lib/string.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7/*
8 * stupid library routines.. The optimized versions should generally be found
9 * as inline code in <asm-xx/string.h>
10 *
11 * These are buggy as well..
12 *
13 * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
14 * - Added strsep() which will replace strtok() soon (because strsep() is
15 * reentrant and should be faster). Use only strsep() in new code, please.
16 */
17
Simon Glass96794a32018-11-06 15:21:38 -070018#include <config.h>
wdenkc6097192002-11-03 00:24:07 +000019#include <linux/types.h>
20#include <linux/string.h>
21#include <linux/ctype.h>
22#include <malloc.h>
23
wdenkc6097192002-11-03 00:24:07 +000024
wdenkc6097192002-11-03 00:24:07 +000025/**
Simon Glassb1f17bf2012-12-05 14:46:35 +000026 * strncasecmp - Case insensitive, length-limited string comparison
wdenkc6097192002-11-03 00:24:07 +000027 * @s1: One string
28 * @s2: The other string
29 * @len: the maximum number of characters to compare
30 */
Simon Glassb1f17bf2012-12-05 14:46:35 +000031int strncasecmp(const char *s1, const char *s2, size_t len)
wdenkc6097192002-11-03 00:24:07 +000032{
33 /* Yes, Virginia, it had better be unsigned */
34 unsigned char c1, c2;
35
36 c1 = 0; c2 = 0;
37 if (len) {
38 do {
39 c1 = *s1; c2 = *s2;
40 s1++; s2++;
41 if (!c1)
42 break;
43 if (!c2)
44 break;
45 if (c1 == c2)
46 continue;
47 c1 = tolower(c1);
48 c2 = tolower(c2);
49 if (c1 != c2)
50 break;
51 } while (--len);
52 }
53 return (int)c1 - (int)c2;
54}
Simon Glassb1f17bf2012-12-05 14:46:35 +000055
56/**
57 * strcasecmp - Case insensitive string comparison
58 * @s1: One string
59 * @s2: The other string
60 */
61int strcasecmp(const char *s1, const char *s2)
62{
63 return strncasecmp(s1, s2, -1U);
64}
wdenkc6097192002-11-03 00:24:07 +000065
66char * ___strtok;
67
68#ifndef __HAVE_ARCH_STRCPY
69/**
70 * strcpy - Copy a %NUL terminated string
71 * @dest: Where to copy the string to
72 * @src: Where to copy the string from
73 */
74char * strcpy(char * dest,const char *src)
75{
76 char *tmp = dest;
77
78 while ((*dest++ = *src++) != '\0')
79 /* nothing */;
80 return tmp;
81}
82#endif
83
84#ifndef __HAVE_ARCH_STRNCPY
85/**
86 * strncpy - Copy a length-limited, %NUL-terminated string
87 * @dest: Where to copy the string to
88 * @src: Where to copy the string from
89 * @count: The maximum number of bytes to copy
90 *
91 * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
92 * However, the result is not %NUL-terminated if the source exceeds
93 * @count bytes.
94 */
95char * strncpy(char * dest,const char *src,size_t count)
96{
97 char *tmp = dest;
98
99 while (count-- && (*dest++ = *src++) != '\0')
100 /* nothing */;
101
102 return tmp;
103}
104#endif
105
Masahiro Yamada80d9ef82014-11-20 21:20:32 +0900106#ifndef __HAVE_ARCH_STRLCPY
107/**
108 * strlcpy - Copy a C-string into a sized buffer
109 * @dest: Where to copy the string to
110 * @src: Where to copy the string from
111 * @size: size of destination buffer
112 *
113 * Compatible with *BSD: the result is always a valid
114 * NUL-terminated string that fits in the buffer (unless,
115 * of course, the buffer size is zero). It does not pad
116 * out the result like strncpy() does.
117 */
118size_t strlcpy(char *dest, const char *src, size_t size)
119{
120 size_t ret = strlen(src);
121
122 if (size) {
123 size_t len = (ret >= size) ? size - 1 : ret;
124 memcpy(dest, src, len);
125 dest[len] = '\0';
126 }
127 return ret;
128}
129#endif
130
wdenkc6097192002-11-03 00:24:07 +0000131#ifndef __HAVE_ARCH_STRCAT
132/**
133 * strcat - Append one %NUL-terminated string to another
134 * @dest: The string to be appended to
135 * @src: The string to append to it
136 */
137char * strcat(char * dest, const char * src)
138{
139 char *tmp = dest;
140
141 while (*dest)
142 dest++;
143 while ((*dest++ = *src++) != '\0')
144 ;
145
146 return tmp;
147}
148#endif
149
150#ifndef __HAVE_ARCH_STRNCAT
151/**
152 * strncat - Append a length-limited, %NUL-terminated string to another
153 * @dest: The string to be appended to
154 * @src: The string to append to it
155 * @count: The maximum numbers of bytes to copy
156 *
157 * Note that in contrast to strncpy, strncat ensures the result is
158 * terminated.
159 */
160char * strncat(char *dest, const char *src, size_t count)
161{
162 char *tmp = dest;
163
164 if (count) {
165 while (*dest)
166 dest++;
167 while ((*dest++ = *src++)) {
168 if (--count == 0) {
169 *dest = '\0';
170 break;
171 }
172 }
173 }
174
175 return tmp;
176}
177#endif
178
179#ifndef __HAVE_ARCH_STRCMP
180/**
181 * strcmp - Compare two strings
182 * @cs: One string
183 * @ct: Another string
184 */
185int strcmp(const char * cs,const char * ct)
186{
187 register signed char __res;
188
189 while (1) {
190 if ((__res = *cs - *ct++) != 0 || !*cs++)
191 break;
192 }
193
194 return __res;
195}
196#endif
197
198#ifndef __HAVE_ARCH_STRNCMP
199/**
200 * strncmp - Compare two length-limited strings
201 * @cs: One string
202 * @ct: Another string
203 * @count: The maximum number of bytes to compare
204 */
205int strncmp(const char * cs,const char * ct,size_t count)
206{
207 register signed char __res = 0;
208
209 while (count) {
210 if ((__res = *cs - *ct++) != 0 || !*cs++)
211 break;
212 count--;
213 }
214
215 return __res;
216}
217#endif
218
219#ifndef __HAVE_ARCH_STRCHR
220/**
221 * strchr - Find the first occurrence of a character in a string
222 * @s: The string to be searched
223 * @c: The character to search for
224 */
225char * strchr(const char * s, int c)
226{
227 for(; *s != (char) c; ++s)
228 if (*s == '\0')
229 return NULL;
230 return (char *) s;
231}
232#endif
233
Simon Glass6b45ba42017-05-18 20:09:28 -0600234const char *strchrnul(const char *s, int c)
235{
236 for (; *s != (char)c; ++s)
237 if (*s == '\0')
238 break;
239 return s;
240}
241
wdenkc6097192002-11-03 00:24:07 +0000242#ifndef __HAVE_ARCH_STRRCHR
243/**
244 * strrchr - Find the last occurrence of a character in a string
245 * @s: The string to be searched
246 * @c: The character to search for
247 */
248char * strrchr(const char * s, int c)
249{
250 const char *p = s + strlen(s);
251 do {
wdenk8bde7f72003-06-27 21:31:46 +0000252 if (*p == (char)c)
253 return (char *)p;
wdenkc6097192002-11-03 00:24:07 +0000254 } while (--p >= s);
255 return NULL;
256}
257#endif
258
259#ifndef __HAVE_ARCH_STRLEN
260/**
261 * strlen - Find the length of a string
262 * @s: The string to be sized
263 */
264size_t strlen(const char * s)
265{
266 const char *sc;
267
268 for (sc = s; *sc != '\0'; ++sc)
269 /* nothing */;
270 return sc - s;
271}
272#endif
273
274#ifndef __HAVE_ARCH_STRNLEN
275/**
276 * strnlen - Find the length of a length-limited string
277 * @s: The string to be sized
278 * @count: The maximum number of bytes to search
279 */
280size_t strnlen(const char * s, size_t count)
281{
282 const char *sc;
283
284 for (sc = s; count-- && *sc != '\0'; ++sc)
285 /* nothing */;
286 return sc - s;
287}
288#endif
289
Simon Glassa7d00212017-05-18 20:09:29 -0600290#ifndef __HAVE_ARCH_STRCSPN
291/**
292 * strcspn - Calculate the length of the initial substring of @s which does
293 * not contain letters in @reject
294 * @s: The string to be searched
295 * @reject: The string to avoid
296 */
297size_t strcspn(const char *s, const char *reject)
298{
299 const char *p;
300 const char *r;
301 size_t count = 0;
302
303 for (p = s; *p != '\0'; ++p) {
304 for (r = reject; *r != '\0'; ++r) {
305 if (*p == *r)
306 return count;
307 }
308 ++count;
309 }
310 return count;
311}
312#endif
313
wdenkc6097192002-11-03 00:24:07 +0000314#ifndef __HAVE_ARCH_STRDUP
315char * strdup(const char *s)
316{
317 char *new;
318
319 if ((s == NULL) ||
320 ((new = malloc (strlen(s) + 1)) == NULL) ) {
321 return NULL;
322 }
323
324 strcpy (new, s);
325 return new;
326}
wdenkc6097192002-11-03 00:24:07 +0000327
Thierry Reding0c4e2652019-04-15 11:32:14 +0200328char * strndup(const char *s, size_t n)
329{
330 size_t len;
331 char *new;
332
333 if (s == NULL)
334 return NULL;
335
336 len = strlen(s);
337
338 if (n < len)
339 len = n;
340
341 new = malloc(len + 1);
342 if (new == NULL)
343 return NULL;
344
345 strncpy(new, s, len);
346 new[len] = '\0';
347
348 return new;
349}
Simon Glass1ea1c7d2020-02-03 07:36:00 -0700350#endif
Thierry Reding0c4e2652019-04-15 11:32:14 +0200351
wdenkc6097192002-11-03 00:24:07 +0000352#ifndef __HAVE_ARCH_STRSPN
353/**
354 * strspn - Calculate the length of the initial substring of @s which only
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200355 * contain letters in @accept
wdenkc6097192002-11-03 00:24:07 +0000356 * @s: The string to be searched
357 * @accept: The string to search for
358 */
359size_t strspn(const char *s, const char *accept)
360{
361 const char *p;
362 const char *a;
363 size_t count = 0;
364
365 for (p = s; *p != '\0'; ++p) {
366 for (a = accept; *a != '\0'; ++a) {
367 if (*p == *a)
368 break;
369 }
370 if (*a == '\0')
371 return count;
372 ++count;
373 }
374
375 return count;
376}
377#endif
378
379#ifndef __HAVE_ARCH_STRPBRK
380/**
381 * strpbrk - Find the first occurrence of a set of characters
382 * @cs: The string to be searched
383 * @ct: The characters to search for
384 */
385char * strpbrk(const char * cs,const char * ct)
386{
387 const char *sc1,*sc2;
388
389 for( sc1 = cs; *sc1 != '\0'; ++sc1) {
390 for( sc2 = ct; *sc2 != '\0'; ++sc2) {
391 if (*sc1 == *sc2)
392 return (char *) sc1;
393 }
394 }
395 return NULL;
396}
397#endif
398
399#ifndef __HAVE_ARCH_STRTOK
400/**
401 * strtok - Split a string into tokens
402 * @s: The string to be searched
403 * @ct: The characters to search for
404 *
405 * WARNING: strtok is deprecated, use strsep instead.
406 */
407char * strtok(char * s,const char * ct)
408{
409 char *sbegin, *send;
410
411 sbegin = s ? s : ___strtok;
412 if (!sbegin) {
413 return NULL;
414 }
415 sbegin += strspn(sbegin,ct);
416 if (*sbegin == '\0') {
417 ___strtok = NULL;
418 return( NULL );
419 }
420 send = strpbrk( sbegin, ct);
421 if (send && *send != '\0')
422 *send++ = '\0';
423 ___strtok = send;
424 return (sbegin);
425}
426#endif
427
428#ifndef __HAVE_ARCH_STRSEP
429/**
430 * strsep - Split a string into tokens
431 * @s: The string to be searched
432 * @ct: The characters to search for
433 *
434 * strsep() updates @s to point after the token, ready for the next call.
435 *
436 * It returns empty tokens, too, behaving exactly like the libc function
437 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
438 * Same semantics, slimmer shape. ;)
439 */
440char * strsep(char **s, const char *ct)
441{
442 char *sbegin = *s, *end;
443
444 if (sbegin == NULL)
445 return NULL;
446
447 end = strpbrk(sbegin, ct);
448 if (end)
449 *end++ = '\0';
450 *s = end;
451
452 return sbegin;
453}
454#endif
455
wdenkc3f9d492004-03-14 00:59:59 +0000456#ifndef __HAVE_ARCH_STRSWAB
457/**
458 * strswab - swap adjacent even and odd bytes in %NUL-terminated string
459 * s: address of the string
460 *
461 * returns the address of the swapped string or NULL on error. If
462 * string length is odd, last byte is untouched.
463 */
464char *strswab(const char *s)
465{
Wolfgang Denk389db1f2005-09-25 16:15:17 +0200466 char *p, *q;
wdenkc3f9d492004-03-14 00:59:59 +0000467
468 if ((NULL == s) || ('\0' == *s)) {
469 return (NULL);
470 }
471
Wolfgang Denke5e98ed2005-10-04 23:38:07 +0200472 for (p=(char *)s, q=p+1; (*p != '\0') && (*q != '\0'); p+=2, q+=2) {
wdenkc3f9d492004-03-14 00:59:59 +0000473 char tmp;
Wolfgang Denk389db1f2005-09-25 16:15:17 +0200474
475 tmp = *p;
476 *p = *q;
477 *q = tmp;
wdenkc3f9d492004-03-14 00:59:59 +0000478 }
479
480 return (char *) s;
481}
482#endif
483
wdenkc6097192002-11-03 00:24:07 +0000484#ifndef __HAVE_ARCH_MEMSET
485/**
486 * memset - Fill a region of memory with the given value
487 * @s: Pointer to the start of the area.
488 * @c: The byte to fill the area with
489 * @count: The size of the area.
490 *
491 * Do not use memset() to access IO space, use memset_io() instead.
492 */
493void * memset(void * s,int c,size_t count)
494{
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200495 unsigned long *sl = (unsigned long *) s;
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200496 char *s8;
Simon Glassab4458b2017-04-02 09:50:28 -0600497
498#if !CONFIG_IS_ENABLED(TINY_MEMSET)
499 unsigned long cl = 0;
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200500 int i;
wdenkc6097192002-11-03 00:24:07 +0000501
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200502 /* do it one word at a time (32 bits or 64 bits) while possible */
503 if ( ((ulong)s & (sizeof(*sl) - 1)) == 0) {
504 for (i = 0; i < sizeof(*sl); i++) {
505 cl <<= 8;
506 cl |= c & 0xff;
507 }
508 while (count >= sizeof(*sl)) {
509 *sl++ = cl;
510 count -= sizeof(*sl);
511 }
512 }
Simon Glassab4458b2017-04-02 09:50:28 -0600513#endif /* fill 8 bits at a time */
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200514 s8 = (char *)sl;
wdenkc6097192002-11-03 00:24:07 +0000515 while (count--)
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200516 *s8++ = c;
wdenkc6097192002-11-03 00:24:07 +0000517
518 return s;
519}
520#endif
521
wdenkc6097192002-11-03 00:24:07 +0000522#ifndef __HAVE_ARCH_MEMCPY
523/**
524 * memcpy - Copy one area of memory to another
525 * @dest: Where to copy to
526 * @src: Where to copy from
527 * @count: The size of the area.
528 *
529 * You should not use this function to access IO space, use memcpy_toio()
530 * or memcpy_fromio() instead.
531 */
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200532void * memcpy(void *dest, const void *src, size_t count)
wdenkc6097192002-11-03 00:24:07 +0000533{
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200534 unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src;
535 char *d8, *s8;
wdenkc6097192002-11-03 00:24:07 +0000536
Matthias Weisserb038db82011-05-22 23:03:55 +0000537 if (src == dest)
538 return dest;
539
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200540 /* while all data is aligned (common case), copy a word at a time */
541 if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) {
542 while (count >= sizeof(*dl)) {
543 *dl++ = *sl++;
544 count -= sizeof(*dl);
545 }
546 }
547 /* copy the reset one byte at a time */
548 d8 = (char *)dl;
549 s8 = (char *)sl;
wdenkc6097192002-11-03 00:24:07 +0000550 while (count--)
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200551 *d8++ = *s8++;
wdenkc6097192002-11-03 00:24:07 +0000552
553 return dest;
554}
555#endif
556
557#ifndef __HAVE_ARCH_MEMMOVE
558/**
559 * memmove - Copy one area of memory to another
560 * @dest: Where to copy to
561 * @src: Where to copy from
562 * @count: The size of the area.
563 *
564 * Unlike memcpy(), memmove() copes with overlapping areas.
565 */
566void * memmove(void * dest,const void *src,size_t count)
567{
568 char *tmp, *s;
569
570 if (dest <= src) {
Simon Glasscb0eae82017-04-05 16:23:31 -0600571 memcpy(dest, src, count);
572 } else {
wdenkc6097192002-11-03 00:24:07 +0000573 tmp = (char *) dest + count;
574 s = (char *) src + count;
575 while (count--)
576 *--tmp = *--s;
577 }
578
579 return dest;
580}
581#endif
582
583#ifndef __HAVE_ARCH_MEMCMP
584/**
585 * memcmp - Compare two areas of memory
586 * @cs: One area of memory
587 * @ct: Another area of memory
588 * @count: The size of the area.
589 */
590int memcmp(const void * cs,const void * ct,size_t count)
591{
592 const unsigned char *su1, *su2;
593 int res = 0;
594
595 for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
596 if ((res = *su1 - *su2) != 0)
597 break;
598 return res;
599}
600#endif
601
602#ifndef __HAVE_ARCH_MEMSCAN
603/**
604 * memscan - Find a character in an area of memory.
605 * @addr: The memory area
606 * @c: The byte to search for
607 * @size: The size of the area.
608 *
609 * returns the address of the first occurrence of @c, or 1 byte past
610 * the area if @c is not found
611 */
612void * memscan(void * addr, int c, size_t size)
613{
614 unsigned char * p = (unsigned char *) addr;
615
616 while (size) {
617 if (*p == c)
618 return (void *) p;
619 p++;
620 size--;
621 }
wdenk8bde7f72003-06-27 21:31:46 +0000622 return (void *) p;
wdenkc6097192002-11-03 00:24:07 +0000623}
624#endif
625
626#ifndef __HAVE_ARCH_STRSTR
627/**
628 * strstr - Find the first substring in a %NUL terminated string
629 * @s1: The string to be searched
630 * @s2: The string to search for
631 */
632char * strstr(const char * s1,const char * s2)
633{
634 int l1, l2;
635
636 l2 = strlen(s2);
637 if (!l2)
638 return (char *) s1;
639 l1 = strlen(s1);
640 while (l1 >= l2) {
641 l1--;
642 if (!memcmp(s1,s2,l2))
643 return (char *) s1;
644 s1++;
645 }
646 return NULL;
647}
648#endif
649
650#ifndef __HAVE_ARCH_MEMCHR
651/**
652 * memchr - Find a character in an area of memory.
653 * @s: The memory area
654 * @c: The byte to search for
655 * @n: The size of the area.
656 *
657 * returns the address of the first occurrence of @c, or %NULL
658 * if @c is not found
659 */
660void *memchr(const void *s, int c, size_t n)
661{
662 const unsigned char *p = s;
663 while (n-- != 0) {
wdenk8bde7f72003-06-27 21:31:46 +0000664 if ((unsigned char)c == *p++) {
wdenkc6097192002-11-03 00:24:07 +0000665 return (void *)(p-1);
666 }
667 }
668 return NULL;
669}
670
671#endif
Sergey Lapindfe64e22013-01-14 03:46:50 +0000672#ifndef __HAVE_ARCH_MEMCHR_INV
673static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
674{
675 while (bytes) {
676 if (*start != value)
677 return (void *)start;
678 start++;
679 bytes--;
680 }
681 return NULL;
682}
683/**
684 * memchr_inv - Find an unmatching character in an area of memory.
685 * @start: The memory area
686 * @c: Find a character other than c
687 * @bytes: The size of the area.
688 *
689 * returns the address of the first character other than @c, or %NULL
690 * if the whole buffer contains just @c.
691 */
692void *memchr_inv(const void *start, int c, size_t bytes)
693{
694 u8 value = c;
695 u64 value64;
696 unsigned int words, prefix;
697
698 if (bytes <= 16)
699 return check_bytes8(start, value, bytes);
700
701 value64 = value;
702 value64 |= value64 << 8;
703 value64 |= value64 << 16;
704 value64 |= value64 << 32;
705
706 prefix = (unsigned long)start % 8;
707 if (prefix) {
708 u8 *r;
709
710 prefix = 8 - prefix;
711 r = check_bytes8(start, value, prefix);
712 if (r)
713 return r;
714 start += prefix;
715 bytes -= prefix;
716 }
717
718 words = bytes / 8;
719
720 while (words) {
721 if (*(u64 *)start != value64)
722 return check_bytes8(start, value, 8);
723 start += 8;
724 words--;
725 }
726
727 return check_bytes8(start, value, bytes % 8);
728}
729#endif