xref: /illumos-gate/usr/src/cmd/sendmail/libsm/strto.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /*
2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
3  *      All rights reserved.
4  * Copyright (c) 1992
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * By using this file, you agree to the terms and conditions set
8  * forth in the LICENSE file which can be found at the top level of
9  * the sendmail distribution.
10  */
11 
12 #include <sm/gen.h>
13 SM_IDSTR(id, "@(#)$Id: strto.c,v 1.18 2001/12/30 04:59:37 gshapiro Exp $")
14 
15 #include <sys/param.h>
16 #include <sys/types.h>
17 #include <stdlib.h>
18 #include <ctype.h>
19 #include <errno.h>
20 #include <sm/limits.h>
21 #include <sm/conf.h>
22 #include <sm/string.h>
23 
24 /*
25 **  SM_STRTOLL --  Convert a string to a (signed) long long integer.
26 **
27 **  Ignores `locale' stuff.  Assumes that the upper and lower case
28 **  alphabets and digits are each contiguous.
29 **
30 **	Parameters:
31 **		nptr -- string containing number
32 **		endptr -- location of first invalid character
33 **		base -- numeric base that 'nptr' number is based in
34 **
35 **	Returns:
36 **		Failure: on underflow LLONG_MIN is returned; on overflow
37 **			LLONG_MAX is returned and errno is set.
38 **			When 'endptr' == '\0' then the entire string 'nptr'
39 **			was valid.
40 **		Success: returns the converted number
41 */
42 
43 LONGLONG_T
44 sm_strtoll(nptr, endptr, base)
45 	const char *nptr;
46 	char **endptr;
47 	register int base;
48 {
49 	register bool neg;
50 	register const char *s;
51 	register LONGLONG_T acc, cutoff;
52 	register int c;
53 	register int any, cutlim;
54 
55 	/*
56 	**  Skip white space and pick up leading +/- sign if any.
57 	**  If base is 0, allow 0x for hex and 0 for octal, else
58 	**  assume decimal; if base is already 16, allow 0x.
59 	*/
60 
61 	s = nptr;
62 	do
63 	{
64 		c = (unsigned char) *s++;
65 	} while (isascii(c) && isspace(c));
66 	if (c == '-')
67 	{
68 		neg = true;
69 		c = *s++;
70 	}
71 	else
72 	{
73 		neg = false;
74 		if (c == '+')
75 			c = *s++;
76 	}
77 	if ((base == 0 || base == 16) &&
78 	    c == '0' && (*s == 'x' || *s == 'X'))
79 	{
80 		c = s[1];
81 		s += 2;
82 		base = 16;
83 	}
84 	if (base == 0)
85 		base = c == '0' ? 8 : 10;
86 
87 	/*
88 	**  Compute the cutoff value between legal numbers and illegal
89 	**  numbers.  That is the largest legal value, divided by the
90 	**  base.  An input number that is greater than this value, if
91 	**  followed by a legal input character, is too big.  One that
92 	**  is equal to this value may be valid or not; the limit
93 	**  between valid and invalid numbers is then based on the last
94 	**  digit.  For instance, if the range for long-long's is
95 	**  [-9223372036854775808..9223372036854775807] and the input base
96 	**  is 10, cutoff will be set to 922337203685477580 and cutlim to
97 	**  either 7 (!neg) or 8 (neg), meaning that if we have
98 	**  accumulated a value > 922337203685477580, or equal but the
99 	**  next digit is > 7 (or 8), the number is too big, and we will
100 	**  return a range error.
101 	**
102 	**  Set any if any `digits' consumed; make it negative to indicate
103 	**  overflow.
104 	*/
105 
106 	cutoff = neg ? LLONG_MIN : LLONG_MAX;
107 	cutlim = cutoff % base;
108 	cutoff /= base;
109 	if (neg)
110 	{
111 		if (cutlim > 0)
112 		{
113 			cutlim -= base;
114 			cutoff += 1;
115 		}
116 		cutlim = -cutlim;
117 	}
118 	for (acc = 0, any = 0;; c = (unsigned char) *s++)
119 	{
120 		if (isascii(c) && isdigit(c))
121 			c -= '0';
122 		else if (isascii(c) && isalpha(c))
123 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
124 		else
125 			break;
126 		if (c >= base)
127 			break;
128 		if (any < 0)
129 			continue;
130 		if (neg)
131 		{
132 			if (acc < cutoff || (acc == cutoff && c > cutlim))
133 			{
134 				any = -1;
135 				acc = LLONG_MIN;
136 				errno = ERANGE;
137 			}
138 			else
139 			{
140 				any = 1;
141 				acc *= base;
142 				acc -= c;
143 			}
144 		}
145 		else
146 		{
147 			if (acc > cutoff || (acc == cutoff && c > cutlim))
148 			{
149 				any = -1;
150 				acc = LLONG_MAX;
151 				errno = ERANGE;
152 			}
153 			else
154 			{
155 				any = 1;
156 				acc *= base;
157 				acc += c;
158 			}
159 		}
160 	}
161 	if (endptr != 0)
162 		*endptr = (char *) (any ? s - 1 : nptr);
163 	return acc;
164 }
165 
166 /*
167 **  SM_STRTOULL --  Convert a string to an unsigned long long integer.
168 **
169 **  Ignores `locale' stuff.  Assumes that the upper and lower case
170 **  alphabets and digits are each contiguous.
171 **
172 **	Parameters:
173 **		nptr -- string containing (unsigned) number
174 **		endptr -- location of first invalid character
175 **		base -- numeric base that 'nptr' number is based in
176 **
177 **	Returns:
178 **		Failure: on overflow ULLONG_MAX is returned and errno is set.
179 **			When 'endptr' == '\0' then the entire string 'nptr'
180 **			was valid.
181 **		Success: returns the converted number
182 */
183 
184 ULONGLONG_T
185 sm_strtoull(nptr, endptr, base)
186 	const char *nptr;
187 	char **endptr;
188 	register int base;
189 {
190 	register const char *s;
191 	register ULONGLONG_T acc, cutoff;
192 	register int c;
193 	register bool neg;
194 	register int any, cutlim;
195 
196 	/* See sm_strtoll for comments as to the logic used. */
197 	s = nptr;
198 	do
199 	{
200 		c = (unsigned char) *s++;
201 	} while (isascii(c) && isspace(c));
202 	neg = (c == '-');
203 	if (neg)
204 	{
205 		c = *s++;
206 	}
207 	else
208 	{
209 		if (c == '+')
210 			c = *s++;
211 	}
212 	if ((base == 0 || base == 16) &&
213 	    c == '0' && (*s == 'x' || *s == 'X'))
214 	{
215 		c = s[1];
216 		s += 2;
217 		base = 16;
218 	}
219 	if (base == 0)
220 		base = c == '0' ? 8 : 10;
221 
222 	cutoff = ULLONG_MAX / (ULONGLONG_T)base;
223 	cutlim = ULLONG_MAX % (ULONGLONG_T)base;
224 	for (acc = 0, any = 0;; c = (unsigned char) *s++)
225 	{
226 		if (isascii(c) && isdigit(c))
227 			c -= '0';
228 		else if (isascii(c) && isalpha(c))
229 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
230 		else
231 			break;
232 		if (c >= base)
233 			break;
234 		if (any < 0)
235 			continue;
236 		if (acc > cutoff || (acc == cutoff && c > cutlim))
237 		{
238 			any = -1;
239 			acc = ULLONG_MAX;
240 			errno = ERANGE;
241 		}
242 		else
243 		{
244 			any = 1;
245 			acc *= (ULONGLONG_T)base;
246 			acc += c;
247 		}
248 	}
249 	if (neg && any > 0)
250 		acc = -((LONGLONG_T) acc);
251 	if (endptr != 0)
252 		*endptr = (char *) (any ? s - 1 : nptr);
253 	return acc;
254 }
255