1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
6  * Copyright (c) 2014-2015 François Tigeot
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 #ifndef	_LINUXKPI_LINUX_KERNEL_H_
31 #define	_LINUXKPI_LINUX_KERNEL_H_
32 
33 #include <sys/cdefs.h>
34 #include <sys/types.h>
35 #include <sys/systm.h>
36 #include <sys/param.h>
37 #include <sys/libkern.h>
38 #include <sys/stat.h>
39 #include <sys/smp.h>
40 #include <sys/stddef.h>
41 #include <sys/syslog.h>
42 #include <sys/time.h>
43 
44 #include <linux/bitops.h>
45 #include <linux/build_bug.h>
46 #include <linux/compiler.h>
47 #include <linux/container_of.h>
48 #include <linux/stringify.h>
49 #include <linux/errno.h>
50 #include <linux/sched.h>
51 #include <linux/types.h>
52 #include <linux/typecheck.h>
53 #include <linux/jiffies.h>
54 #include <linux/log2.h>
55 #include <linux/kconfig.h>
56 
57 #include <asm/byteorder.h>
58 #include <asm/cpufeature.h>
59 #include <asm/processor.h>
60 #include <asm/uaccess.h>
61 
62 #include <linux/stdarg.h>
63 
64 #define KERN_CONT       ""
65 #define	KERN_EMERG	"<0>"
66 #define	KERN_ALERT	"<1>"
67 #define	KERN_CRIT	"<2>"
68 #define	KERN_ERR	"<3>"
69 #define	KERN_WARNING	"<4>"
70 #define	KERN_NOTICE	"<5>"
71 #define	KERN_INFO	"<6>"
72 #define	KERN_DEBUG	"<7>"
73 
74 #define	U8_MAX		((u8)~0U)
75 #define	S8_MAX		((s8)(U8_MAX >> 1))
76 #define	S8_MIN		((s8)(-S8_MAX - 1))
77 #define	U16_MAX		((u16)~0U)
78 #define	S16_MAX		((s16)(U16_MAX >> 1))
79 #define	S16_MIN		((s16)(-S16_MAX - 1))
80 #define	U32_MAX		((u32)~0U)
81 #define	S32_MAX		((s32)(U32_MAX >> 1))
82 #define	S32_MIN		((s32)(-S32_MAX - 1))
83 #define	U64_MAX		((u64)~0ULL)
84 #define	S64_MAX		((s64)(U64_MAX >> 1))
85 #define	S64_MIN		((s64)(-S64_MAX - 1))
86 
87 #define	S8_C(x)  x
88 #define	U8_C(x)  x ## U
89 #define	S16_C(x) x
90 #define	U16_C(x) x ## U
91 #define	S32_C(x) x
92 #define	U32_C(x) x ## U
93 #define	S64_C(x) x ## LL
94 #define	U64_C(x) x ## ULL
95 
96 #define	BUG()			panic("BUG at %s:%d", __FILE__, __LINE__)
97 #define	BUG_ON(cond)		do {				\
98 	if (cond) {						\
99 		panic("BUG ON %s failed at %s:%d",		\
100 		    __stringify(cond), __FILE__, __LINE__);	\
101 	}							\
102 } while (0)
103 
104 extern int linuxkpi_warn_dump_stack;
105 #define	WARN_ON(cond) ({					\
106 	bool __ret = (cond);					\
107 	if (__ret) {						\
108 		printf("WARNING %s failed at %s:%d\n",		\
109 		    __stringify(cond), __FILE__, __LINE__);	\
110 		if (linuxkpi_warn_dump_stack)				\
111 			linux_dump_stack();				\
112 	}								\
113 	unlikely(__ret);						\
114 })
115 
116 #define	WARN_ON_SMP(cond)	WARN_ON(cond)
117 
118 #define	WARN_ON_ONCE(cond) ({					\
119 	static bool __warn_on_once;				\
120 	bool __ret = (cond);					\
121 	if (__ret && !__warn_on_once) {				\
122 		__warn_on_once = 1;				\
123 		printf("WARNING %s failed at %s:%d\n",		\
124 		    __stringify(cond), __FILE__, __LINE__);	\
125 		if (linuxkpi_warn_dump_stack)				\
126 			linux_dump_stack();				\
127 	}								\
128 	unlikely(__ret);						\
129 })
130 
131 #define	oops_in_progress	SCHEDULER_STOPPED()
132 
133 #undef	ALIGN
134 #define	ALIGN(x, y)		roundup2((x), (y))
135 #define	ALIGN_DOWN(x, y)	rounddown2(x, y)
136 #undef PTR_ALIGN
137 #define	PTR_ALIGN(p, a)		((__typeof(p))ALIGN((uintptr_t)(p), (a)))
138 #define	IS_ALIGNED(x, a)	(((x) & ((__typeof(x))(a) - 1)) == 0)
139 #define	DIV_ROUND_UP(x, n)	howmany(x, n)
140 #define	__KERNEL_DIV_ROUND_UP(x, n)	howmany(x, n)
141 #define	DIV_ROUND_UP_ULL(x, n)	DIV_ROUND_UP((unsigned long long)(x), (n))
142 #define	DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n))
143 #define	FIELD_SIZEOF(t, f)	sizeof(((t *)0)->f)
144 
145 #define	printk(...)		printf(__VA_ARGS__)
146 #define	vprintk(f, a)		vprintf(f, a)
147 
148 #define	asm			__asm
149 
150 extern void linux_dump_stack(void);
151 #define	dump_stack()		linux_dump_stack()
152 
153 struct va_format {
154 	const char *fmt;
155 	va_list *va;
156 };
157 
158 static inline int
159 vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
160 {
161 	ssize_t ssize = size;
162 	int i;
163 
164 	i = vsnprintf(buf, size, fmt, args);
165 
166 	return ((i >= ssize) ? (ssize - 1) : i);
167 }
168 
169 static inline int
170 scnprintf(char *buf, size_t size, const char *fmt, ...)
171 {
172 	va_list args;
173 	int i;
174 
175 	va_start(args, fmt);
176 	i = vscnprintf(buf, size, fmt, args);
177 	va_end(args);
178 
179 	return (i);
180 }
181 
182 /*
183  * The "pr_debug()" and "pr_devel()" macros should produce zero code
184  * unless DEBUG is defined:
185  */
186 #ifdef DEBUG
187 extern int linuxkpi_debug;
188 #define pr_debug(fmt, ...)					\
189 	do {							\
190 		if (linuxkpi_debug)				\
191 			log(LOG_DEBUG, fmt, ##__VA_ARGS__);	\
192 	} while (0)
193 #define pr_devel(fmt, ...) \
194 	log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__)
195 #else
196 #define pr_debug(fmt, ...) \
197 	({ if (0) log(LOG_DEBUG, fmt, ##__VA_ARGS__); 0; })
198 #define pr_devel(fmt, ...) \
199 	({ if (0) log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__); 0; })
200 #endif
201 
202 #ifndef pr_fmt
203 #define pr_fmt(fmt) fmt
204 #endif
205 
206 /*
207  * Print a one-time message (analogous to WARN_ONCE() et al):
208  */
209 #define printk_once(...) do {			\
210 	static bool __print_once;		\
211 						\
212 	if (!__print_once) {			\
213 		__print_once = true;		\
214 		printk(__VA_ARGS__);		\
215 	}					\
216 } while (0)
217 
218 /*
219  * Log a one-time message (analogous to WARN_ONCE() et al):
220  */
221 #define log_once(level,...) do {		\
222 	static bool __log_once;			\
223 						\
224 	if (unlikely(!__log_once)) {		\
225 		__log_once = true;		\
226 		log(level, __VA_ARGS__);	\
227 	}					\
228 } while (0)
229 
230 #define pr_emerg(fmt, ...) \
231 	log(LOG_EMERG, pr_fmt(fmt), ##__VA_ARGS__)
232 #define pr_alert(fmt, ...) \
233 	log(LOG_ALERT, pr_fmt(fmt), ##__VA_ARGS__)
234 #define pr_crit(fmt, ...) \
235 	log(LOG_CRIT, pr_fmt(fmt), ##__VA_ARGS__)
236 #define pr_err(fmt, ...) \
237 	log(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__)
238 #define pr_err_once(fmt, ...) \
239 	log_once(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__)
240 #define pr_warning(fmt, ...) \
241 	log(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__)
242 #define pr_warn(...) \
243 	pr_warning(__VA_ARGS__)
244 #define pr_warn_once(fmt, ...) \
245 	log_once(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__)
246 #define pr_notice(fmt, ...) \
247 	log(LOG_NOTICE, pr_fmt(fmt), ##__VA_ARGS__)
248 #define pr_info(fmt, ...) \
249 	log(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__)
250 #define pr_info_once(fmt, ...) \
251 	log_once(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__)
252 #define pr_cont(fmt, ...) \
253 	printk(KERN_CONT fmt, ##__VA_ARGS__)
254 #define	pr_warn_ratelimited(...) do {		\
255 	static linux_ratelimit_t __ratelimited;	\
256 	if (linux_ratelimited(&__ratelimited))	\
257 		pr_warning(__VA_ARGS__);	\
258 } while (0)
259 
260 #ifndef WARN
261 #define	WARN(condition, ...) ({			\
262 	bool __ret_warn_on = (condition);	\
263 	if (unlikely(__ret_warn_on))		\
264 		pr_warning(__VA_ARGS__);	\
265 	unlikely(__ret_warn_on);		\
266 })
267 #endif
268 
269 #ifndef WARN_ONCE
270 #define	WARN_ONCE(condition, ...) ({		\
271 	bool __ret_warn_on = (condition);	\
272 	if (unlikely(__ret_warn_on))		\
273 		pr_warn_once(__VA_ARGS__);	\
274 	unlikely(__ret_warn_on);		\
275 })
276 #endif
277 
278 #define	ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
279 
280 #define	u64_to_user_ptr(val)	((void *)(uintptr_t)(val))
281 
282 #define _RET_IP_		__builtin_return_address(0)
283 
284 static inline unsigned long long
285 simple_strtoull(const char *cp, char **endp, unsigned int base)
286 {
287 	return (strtouq(cp, endp, base));
288 }
289 
290 static inline long long
291 simple_strtoll(const char *cp, char **endp, unsigned int base)
292 {
293 	return (strtoq(cp, endp, base));
294 }
295 
296 static inline unsigned long
297 simple_strtoul(const char *cp, char **endp, unsigned int base)
298 {
299 	return (strtoul(cp, endp, base));
300 }
301 
302 static inline long
303 simple_strtol(const char *cp, char **endp, unsigned int base)
304 {
305 	return (strtol(cp, endp, base));
306 }
307 
308 static inline int
309 kstrtoul(const char *cp, unsigned int base, unsigned long *res)
310 {
311 	char *end;
312 
313 	*res = strtoul(cp, &end, base);
314 
315 	/* skip newline character, if any */
316 	if (*end == '\n')
317 		end++;
318 	if (*cp == 0 || *end != 0)
319 		return (-EINVAL);
320 	return (0);
321 }
322 
323 static inline int
324 kstrtol(const char *cp, unsigned int base, long *res)
325 {
326 	char *end;
327 
328 	*res = strtol(cp, &end, base);
329 
330 	/* skip newline character, if any */
331 	if (*end == '\n')
332 		end++;
333 	if (*cp == 0 || *end != 0)
334 		return (-EINVAL);
335 	return (0);
336 }
337 
338 static inline int
339 kstrtoint(const char *cp, unsigned int base, int *res)
340 {
341 	char *end;
342 	long temp;
343 
344 	*res = temp = strtol(cp, &end, base);
345 
346 	/* skip newline character, if any */
347 	if (*end == '\n')
348 		end++;
349 	if (*cp == 0 || *end != 0)
350 		return (-EINVAL);
351 	if (temp != (int)temp)
352 		return (-ERANGE);
353 	return (0);
354 }
355 
356 static inline int
357 kstrtouint(const char *cp, unsigned int base, unsigned int *res)
358 {
359 	char *end;
360 	unsigned long temp;
361 
362 	*res = temp = strtoul(cp, &end, base);
363 
364 	/* skip newline character, if any */
365 	if (*end == '\n')
366 		end++;
367 	if (*cp == 0 || *end != 0)
368 		return (-EINVAL);
369 	if (temp != (unsigned int)temp)
370 		return (-ERANGE);
371 	return (0);
372 }
373 
374 static inline int
375 kstrtou8(const char *cp, unsigned int base, u8 *res)
376 {
377 	char *end;
378 	unsigned long temp;
379 
380 	*res = temp = strtoul(cp, &end, base);
381 
382 	/* skip newline character, if any */
383 	if (*end == '\n')
384 		end++;
385 	if (*cp == 0 || *end != 0)
386 		return (-EINVAL);
387 	if (temp != (u8)temp)
388 		return (-ERANGE);
389 	return (0);
390 }
391 
392 static inline int
393 kstrtou16(const char *cp, unsigned int base, u16 *res)
394 {
395 	char *end;
396 	unsigned long temp;
397 
398 	*res = temp = strtoul(cp, &end, base);
399 
400 	/* skip newline character, if any */
401 	if (*end == '\n')
402 		end++;
403 	if (*cp == 0 || *end != 0)
404 		return (-EINVAL);
405 	if (temp != (u16)temp)
406 		return (-ERANGE);
407 	return (0);
408 }
409 
410 static inline int
411 kstrtou32(const char *cp, unsigned int base, u32 *res)
412 {
413 
414 	return (kstrtouint(cp, base, res));
415 }
416 
417 static inline int
418 kstrtou64(const char *cp, unsigned int base, u64 *res)
419 {
420        char *end;
421 
422        *res = strtouq(cp, &end, base);
423 
424        /* skip newline character, if any */
425        if (*end == '\n')
426                end++;
427        if (*cp == 0 || *end != 0)
428                return (-EINVAL);
429        return (0);
430 }
431 
432 static inline int
433 kstrtoull(const char *cp, unsigned int base, unsigned long long *res)
434 {
435 	return (kstrtou64(cp, base, (u64 *)res));
436 }
437 
438 static inline int
439 kstrtobool(const char *s, bool *res)
440 {
441 	int len;
442 
443 	if (s == NULL || (len = strlen(s)) == 0 || res == NULL)
444 		return (-EINVAL);
445 
446 	/* skip newline character, if any */
447 	if (s[len - 1] == '\n')
448 		len--;
449 
450 	if (len == 1 && strchr("yY1", s[0]) != NULL)
451 		*res = true;
452 	else if (len == 1 && strchr("nN0", s[0]) != NULL)
453 		*res = false;
454 	else if (strncasecmp("on", s, len) == 0)
455 		*res = true;
456 	else if (strncasecmp("off", s, len) == 0)
457 		*res = false;
458 	else
459 		return (-EINVAL);
460 
461 	return (0);
462 }
463 
464 static inline int
465 kstrtobool_from_user(const char __user *s, size_t count, bool *res)
466 {
467 	char buf[8] = {};
468 
469 	if (count > (sizeof(buf) - 1))
470 		count = (sizeof(buf) - 1);
471 
472 	if (copy_from_user(buf, s, count))
473 		return (-EFAULT);
474 
475 	return (kstrtobool(buf, res));
476 }
477 
478 static inline int
479 kstrtoint_from_user(const char __user *s, size_t count, unsigned int base,
480     int *p)
481 {
482 	char buf[36] = {};
483 
484 	if (count > (sizeof(buf) - 1))
485 		count = (sizeof(buf) - 1);
486 
487 	if (copy_from_user(buf, s, count))
488 		return (-EFAULT);
489 
490 	return (kstrtoint(buf, base, p));
491 }
492 
493 static inline int
494 kstrtouint_from_user(const char __user *s, size_t count, unsigned int base,
495     unsigned int *p)
496 {
497 	char buf[36] = {};
498 
499 	if (count > (sizeof(buf) - 1))
500 		count = (sizeof(buf) - 1);
501 
502 	if (copy_from_user(buf, s, count))
503 		return (-EFAULT);
504 
505 	return (kstrtouint(buf, base, p));
506 }
507 
508 static inline int
509 kstrtou32_from_user(const char __user *s, size_t count, unsigned int base,
510     unsigned int *p)
511 {
512 
513 	return (kstrtouint_from_user(s, count, base, p));
514 }
515 
516 static inline int
517 kstrtou8_from_user(const char __user *s, size_t count, unsigned int base,
518     u8 *p)
519 {
520 	char buf[8] = {};
521 
522 	if (count > (sizeof(buf) - 1))
523 		count = (sizeof(buf) - 1);
524 
525 	if (copy_from_user(buf, s, count))
526 		return (-EFAULT);
527 
528 	return (kstrtou8(buf, base, p));
529 }
530 
531 #define min(x, y)	((x) < (y) ? (x) : (y))
532 #define max(x, y)	((x) > (y) ? (x) : (y))
533 
534 #define min3(a, b, c)	min(a, min(b,c))
535 #define max3(a, b, c)	max(a, max(b,c))
536 
537 #define	min_t(type, x, y) ({			\
538 	type __min1 = (x);			\
539 	type __min2 = (y);			\
540 	__min1 < __min2 ? __min1 : __min2; })
541 
542 #define	max_t(type, x, y) ({			\
543 	type __max1 = (x);			\
544 	type __max2 = (y);			\
545 	__max1 > __max2 ? __max1 : __max2; })
546 
547 #define offsetofend(t, m)	\
548         (offsetof(t, m) + sizeof((((t *)0)->m)))
549 
550 #define clamp_t(type, _x, min, max)	min_t(type, max_t(type, _x, min), max)
551 #define clamp(x, lo, hi)		min( max(x,lo), hi)
552 #define	clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
553 
554 /*
555  * This looks more complex than it should be. But we need to
556  * get the type for the ~ right in round_down (it needs to be
557  * as wide as the result!), and we want to evaluate the macro
558  * arguments just once each.
559  */
560 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
561 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
562 #define round_down(x, y) ((x) & ~__round_mask(x, y))
563 
564 #define	smp_processor_id()	PCPU_GET(cpuid)
565 #define	num_possible_cpus()	mp_ncpus
566 #define	num_online_cpus()	mp_ncpus
567 
568 #if defined(__i386__) || defined(__amd64__)
569 extern bool linux_cpu_has_clflush;
570 #define	cpu_has_clflush		linux_cpu_has_clflush
571 #endif
572 
573 /* Swap values of a and b */
574 #define swap(a, b) do {			\
575 	typeof(a) _swap_tmp = a;	\
576 	a = b;				\
577 	b = _swap_tmp;			\
578 } while (0)
579 
580 #define	DIV_ROUND_CLOSEST(x, divisor)	(((x) + ((divisor) / 2)) / (divisor))
581 
582 #define	DIV_ROUND_CLOSEST_ULL(x, divisor) ({		\
583 	__typeof(divisor) __d = (divisor);		\
584 	unsigned long long __ret = (x) + (__d) / 2;	\
585 	__ret /= __d;					\
586 	__ret;						\
587 })
588 
589 static inline uintmax_t
590 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor)
591 {
592 	uintmax_t q = (x / divisor);
593 	uintmax_t r = (x % divisor);
594 
595 	return ((q * multiplier) + ((r * multiplier) / divisor));
596 }
597 
598 typedef struct linux_ratelimit {
599 	struct timeval lasttime;
600 	int counter;
601 } linux_ratelimit_t;
602 
603 static inline bool
604 linux_ratelimited(linux_ratelimit_t *rl)
605 {
606 	return (ppsratecheck(&rl->lasttime, &rl->counter, 1));
607 }
608 
609 #define	struct_size(ptr, field, num) ({ \
610 	const size_t __size = offsetof(__typeof(*(ptr)), field); \
611 	const size_t __max = (SIZE_MAX - __size) / sizeof((ptr)->field[0]); \
612 	((num) > __max) ? SIZE_MAX : (__size + sizeof((ptr)->field[0]) * (num)); \
613 })
614 
615 #define	__is_constexpr(x) \
616 	__builtin_constant_p(x)
617 
618 /*
619  * The is_signed() macro below returns true if the passed data type is
620  * signed. Else false is returned.
621  */
622 #define	is_signed(datatype) (((datatype)-1 / (datatype)2) == (datatype)0)
623 
624 /*
625  * The type_max() macro below returns the maxium positive value the
626  * passed data type can hold.
627  */
628 #define	type_max(datatype) ( \
629   (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MAX : UINT64_MAX) : \
630   (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MAX : UINT32_MAX) : \
631   (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MAX : UINT16_MAX) : \
632 			    (is_signed(datatype) ? INT8_MAX : UINT8_MAX) \
633 )
634 
635 /*
636  * The type_min() macro below returns the minimum value the passed
637  * data type can hold. For unsigned types the minimum value is always
638  * zero. For signed types it may vary.
639  */
640 #define	type_min(datatype) ( \
641   (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MIN : 0) : \
642   (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MIN : 0) : \
643   (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MIN : 0) : \
644 			    (is_signed(datatype) ? INT8_MIN : 0) \
645 )
646 
647 #define	TAINT_WARN	0
648 #define	test_taint(x)	(0)
649 #define	add_taint(x,y)	do {	\
650 	} while (0)
651 
652 static inline int
653 _h2b(const char c)
654 {
655 
656 	if (c >= '0' && c <= '9')
657 		return (c - '0');
658 	if (c >= 'a' && c <= 'f')
659 		return (10 + c - 'a');
660 	if (c >= 'A' && c <= 'F')
661 		return (10 + c - 'A');
662 	return (-EINVAL);
663 }
664 
665 static inline int
666 hex2bin(uint8_t *bindst, const char *hexsrc, size_t binlen)
667 {
668 	int hi4, lo4;
669 
670 	while (binlen > 0) {
671 		hi4 = _h2b(*hexsrc++);
672 		lo4 = _h2b(*hexsrc++);
673 		if (hi4 < 0 || lo4 < 0)
674 			return (-EINVAL);
675 
676 		*bindst++ = (hi4 << 4) | lo4;
677 		binlen--;
678 	}
679 
680 	return (0);
681 }
682 
683 static inline bool
684 mac_pton(const char *macin, uint8_t *macout)
685 {
686 	const char *s, *d;
687 	uint8_t mac[6], hx, lx;;
688 	int i;
689 
690 	if (strlen(macin) < (3 * 6 - 1))
691 		return (false);
692 
693 	i = 0;
694 	s = macin;
695 	do {
696 		/* Should we also support '-'-delimiters? */
697 		d = strchrnul(s, ':');
698 		hx = lx = 0;
699 		while (s < d) {
700 			/* Fail on abc:123:xxx:... */
701 			if ((d - s) > 2)
702 				return (false);
703 			/* We do support non-well-formed strings: 3:45:6:... */
704 			if ((d - s) > 1) {
705 				hx = _h2b(*s);
706 				if (hx < 0)
707 					return (false);
708 				s++;
709 			}
710 			lx = _h2b(*s);
711 			if (lx < 0)
712 				return (false);
713 			s++;
714 		}
715 		mac[i] = (hx << 4) | lx;
716 		i++;
717 		if (i >= 6)
718 			return (false);
719 	} while (d != NULL && *d != '\0');
720 
721 	memcpy(macout, mac, 6);
722 	return (true);
723 }
724 
725 #define	DECLARE_FLEX_ARRAY(_t, _n)					\
726     struct { struct { } __dummy_ ## _n; _t _n[0]; }
727 
728 #endif	/* _LINUXKPI_LINUX_KERNEL_H_ */
729