1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
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 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/param.h>
36#include <sys/systm.h>
37#include <sys/ctype.h>
38#include <sys/limits.h>
39
40/*
41 * Convert a string to an unsigned quad integer.
42 *
43 * Ignores `locale' stuff.  Assumes that the upper and lower case
44 * alphabets and digits are each contiguous.
45 */
46u_quad_t
47strtouq(const char *nptr, char **endptr, int base)
48{
49	const char *s = nptr;
50	u_quad_t acc;
51	unsigned char c;
52	u_quad_t qbase, cutoff;
53	int neg, any, cutlim;
54
55	/*
56	 * See strtoq for comments as to the logic used.
57	 */
58	do {
59		c = *s++;
60	} while (isspace(c));
61	if (c == '-') {
62		neg = 1;
63		c = *s++;
64	} else {
65		neg = 0;
66		if (c == '+')
67			c = *s++;
68	}
69	if ((base == 0 || base == 16) &&
70	    c == '0' && (*s == 'x' || *s == 'X')) {
71		c = s[1];
72		s += 2;
73		base = 16;
74	}
75	if (base == 0)
76		base = c == '0' ? 8 : 10;
77	qbase = (unsigned)base;
78	cutoff = (u_quad_t)UQUAD_MAX / qbase;
79	cutlim = (u_quad_t)UQUAD_MAX % qbase;
80	for (acc = 0, any = 0;; c = *s++) {
81		if (!isascii(c))
82			break;
83		if (isdigit(c))
84			c -= '0';
85		else if (isalpha(c))
86			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
87		else
88			break;
89		if (c >= base)
90			break;
91		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
92			any = -1;
93		else {
94			any = 1;
95			acc *= qbase;
96			acc += c;
97		}
98	}
99	if (any < 0) {
100		acc = UQUAD_MAX;
101	} else if (neg)
102		acc = -acc;
103	if (endptr != NULL)
104		*endptr = __DECONST(char *, any ? s - 1 : nptr);
105	return (acc);
106}
107