xref: /illumos-gate/usr/src/common/util/strtoul.c (revision 7b34a9a5df26271af0da06974fc361c468cd48d3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 #if	defined(_KERNEL)
31 #include <sys/null.h>
32 #endif	/* _KERNEL */
33 
34 #if	defined(_KERNEL) && !defined(_BOOT)
35 #include <sys/errno.h>
36 #else	/* _KERNEL && !_BOOT */
37 #if	!defined(_BOOT) && !defined(_KMDB) && !defined(_STANDALONE)
38 #include "lint.h"
39 #endif	/* !_BOOT && !_KMDB && !_STANDALONE */
40 #if	defined(_STANDALONE)
41 #include <sys/cdefs.h>
42 #include <stand.h>
43 #include <limits.h>
44 #else
45 #include <errno.h>
46 #include <ctype.h>
47 #include <limits.h>
48 #include <stdlib.h>
49 #endif	/* _STANDALONE */
50 #endif	/* _KERNEL && !_BOOT */
51 #include "strtolctype.h"
52 #include <sys/types.h>
53 
54 #if	defined(_KERNEL) && !defined(_BOOT)
55 int
56 ddi_strtoul(const char *str, char **nptr, int base, unsigned long *result)
57 #else	/* _KERNEL && !_BOOT */
58 unsigned long
59 strtoul(const char *str, char **nptr, int base)
60 #endif	/* _KERNEL && !_BOOT */
61 {
62 	unsigned long val;
63 	int c;
64 	int xx;
65 	int neg = 0;
66 	unsigned long multmax;
67 	const char **ptr = (const char **)nptr;
68 	const unsigned char *ustr = (const unsigned char *)str;
69 
70 	if (ptr != NULL)
71 		*ptr = (char *)ustr; /* in case no number is formed */
72 	if (base < 0 || base > MBASE || base == 1) {
73 		/* base is invalid -- should be a fatal error */
74 #if	defined(_KERNEL) && !defined(_BOOT)
75 		return (EINVAL);
76 #else	/* _KERNEL && !_BOOT */
77 		errno = EINVAL;
78 		return (0);
79 #endif	/* _KERNEL && !_BOOT */
80 	}
81 	if (!isalnum(c = *ustr)) {
82 		while (isspace(c))
83 			c = *++ustr;
84 		switch (c) {
85 		case '-':
86 			neg++;
87 			/* FALLTHROUGH */
88 		case '+':
89 			c = *++ustr;
90 		}
91 	}
92 	if (base == 0) {
93 		if (c != '0')
94 			base = 10;
95 		else if (ustr[1] == 'x' || ustr[1] == 'X')
96 			base = 16;
97 		else
98 			base = 8;
99 	}
100 	/*
101 	 * for any base > 10, the digits incrementally following
102 	 *	9 are assumed to be "abc...z" or "ABC...Z"
103 	 */
104 	if (!lisalnum(c) || (xx = DIGIT(c)) >= base) {
105 		/* no number formed */
106 #if	defined(_KERNEL) && !defined(_BOOT)
107 		return (EINVAL);
108 #else	/* _KERNEL && !_BOOT */
109 		return (0);
110 #endif	/* _KERNEL && !_BOOT */
111 	}
112 	if (base == 16 && c == '0' && (ustr[1] == 'x' || ustr[1] == 'X') &&
113 	    isxdigit(ustr[2]))
114 		c = *(ustr += 2); /* skip over leading "0x" or "0X" */
115 
116 	multmax = ULONG_MAX / (unsigned long)base;
117 	val = DIGIT(c);
118 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; ) {
119 		if (val > multmax)
120 			goto overflow;
121 		val *= base;
122 		if (ULONG_MAX - val < (unsigned long)xx)
123 			goto overflow;
124 		val += xx;
125 		c = *++ustr;
126 	}
127 	if (ptr != NULL)
128 		*ptr = (char *)ustr;
129 #if	defined(_KERNEL) && !defined(_BOOT)
130 	*result = neg ? -val : val;
131 	return (0);
132 #else	/* _KERNEL && !_BOOT */
133 	return (neg ? -val : val);
134 #endif	/* _KERNEL && !_BOOT */
135 
136 overflow:
137 	for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; (c = *++ustr))
138 		;
139 	if (ptr != NULL)
140 		*ptr = (char *)ustr;
141 #if	defined(_KERNEL) && !defined(_BOOT)
142 	return (ERANGE);
143 #else	/* _KERNEL && !_BOOT */
144 	errno = ERANGE;
145 	return (ULONG_MAX);
146 #endif	/* _KERNEL && !_BOOT */
147 }
148