1 /*
2  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
3  *
4  * This Source Code Form is subject to the terms of the Mozilla Public
5  * License, v. 2.0. If a copy of the MPL was not distributed with this
6  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
7  *
8  * See the COPYRIGHT file distributed with this work for additional
9  * information regarding copyright ownership.
10  */
11 
12 /*
13  * Copyright (c) 1990, 1993
14  *	The Regents of the University of California.  All rights reserved.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  * 3. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 /*! \file */
42 #if defined(LIBC_SCCS) && !defined(lint)
43 static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
44 #endif /* LIBC_SCCS and not lint */
45 
46 #include <config.h>
47 
48 #include <limits.h>
49 #include <ctype.h>
50 #include <errno.h>
51 
52 #include <lwres/stdlib.h>
53 #include <lwres/string.h>
54 
55 #define DE_CONST(konst, var) \
56 	do { \
57 		union { const void *k; void *v; } _u; \
58 		_u.k = konst; \
59 		var = _u.v; \
60 	} while (0)
61 
62 /*!
63  * Convert a string to an unsigned long integer.
64  *
65  * Ignores `locale' stuff.  Assumes that the upper and lower case
66  * alphabets and digits are each contiguous.
67  */
68 unsigned long
lwres_strtoul(const char * nptr,char ** endptr,int base)69 lwres_strtoul(const char *nptr, char **endptr, int base) {
70 	const char *s = nptr;
71 	unsigned long acc;
72 	unsigned char c;
73 	unsigned long cutoff;
74 	int neg = 0, any, cutlim;
75 
76 	/*
77 	 * See strtol for comments as to the logic used.
78 	 */
79 	do {
80 		c = *s++;
81 	} while (isspace(c));
82 	if (c == '-') {
83 		neg = 1;
84 		c = *s++;
85 	} else if (c == '+')
86 		c = *s++;
87 	if ((base == 0 || base == 16) &&
88 	    c == '0' && (*s == 'x' || *s == 'X')) {
89 		c = s[1];
90 		s += 2;
91 		base = 16;
92 	}
93 	if (base == 0)
94 		base = c == '0' ? 8 : 10;
95 	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
96 	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
97 	for (acc = 0, any = 0;; c = *s++) {
98 		if (!isascii(c))
99 			break;
100 		if (isdigit(c))
101 			c -= '0';
102 		else if (isalpha(c))
103 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
104 		else
105 			break;
106 		if (c >= base)
107 			break;
108 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
109 			any = -1;
110 		else {
111 			any = 1;
112 			acc *= base;
113 			acc += c;
114 		}
115 	}
116 	if (any < 0) {
117 		acc = ULONG_MAX;
118 		errno = ERANGE;
119 	} else if (neg)
120 		/* XXX: acc was declared unsigned! */
121 		acc = -acc;
122 	if (endptr != 0)
123 		DE_CONST(any ? s - 1 : nptr, *endptr);
124 	return (acc);
125 }
126 
127 size_t
lwres_strlcpy(char * dst,const char * src,size_t size)128 lwres_strlcpy(char *dst, const char *src, size_t size) {
129 	char *d = dst;
130 	const char *s = src;
131 	size_t n = size;
132 
133 	/* Copy as many bytes as will fit */
134 	if (n != 0U && --n != 0U) {
135 		do {
136 			if ((*d++ = *s++) == 0)
137 				break;
138 		} while (--n != 0U);
139 	}
140 
141 	/* Not enough room in dst, add NUL and traverse rest of src */
142 	if (n == 0U) {
143 		if (size != 0U)
144 			*d = '\0';		/* NUL-terminate dst */
145 		while (*s++)
146 			;
147 	}
148 
149 	return(s - src - 1);	/* count does not include NUL */
150 }
151