xref: /xnu-11215/iokit/Kernel/IOStringFuncs.c (revision bb611c8f)
1 /*
2  * Copyright (c) 1998-2016 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 /*
30  *      Copyright (c) 1995 NeXT Computer, Inc.  All rights reserved.
31  *
32  * strol.c - The functions strtol() & strtoul() are exported as public API
33  *           via the header file ~driverkit/generalFuncs.h
34  *
35  * HISTORY
36  * 25-Oct-1995    Dean Reece at NeXT
37  *      Created based on BSD4.4's strtol.c & strtoul.c.
38  *      Removed dependency on _ctype_ by static versions of isupper()...
39  *      Added support for "0b101..." binary constants.
40  *      Commented out references to errno.
41  */
42 
43 /*
44  * Copyright (c) 1990, 1993
45  *	The Regents of the University of California.  All rights reserved.
46  *
47  * Redistribution and use in source and binary forms, with or without
48  * modification, are permitted provided that the following conditions
49  * are met:
50  * 1. Redistributions of source code must retain the above copyright
51  *    notice, this list of conditions and the following disclaimer.
52  * 2. Redistributions in binary form must reproduce the above copyright
53  *    notice, this list of conditions and the following disclaimer in the
54  *    documentation and/or other materials provided with the distribution.
55  * 3. All advertising materials mentioning features or use of this software
56  *    must display the following acknowledgement:
57  *	This product includes software developed by the University of
58  *	California, Berkeley and its contributors.
59  * 4. Neither the name of the University nor the names of its contributors
60  *    may be used to endorse or promote products derived from this software
61  *    without specific prior written permission.
62  *
63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
73  * SUCH DAMAGE.
74  */
75 
76 /*
77  #include <string.h>
78  #include <stdlib.h>
79  #include <limits.h>
80  */
81 #include <sys/types.h>
82 #include <machine/limits.h>
83 
84 
85 long strtol(const char *nptr, char **endptr, int base);
86 unsigned long strtoul(const char *nptr, char **endptr, int base);
87 quad_t strtoq(const char *nptr, char **endptr, int base);
88 u_quad_t strtouq(const char *nptr, char **endptr, int base);
89 char *strncat(char *s1, const char *s2, unsigned long n);
90 
91 
92 typedef int BOOL;
93 
94 static inline BOOL
95 isupper(char c)
96 {
97 	return c >= 'A' && c <= 'Z';
98 }
99 
100 static inline BOOL
101 isalpha(char c)
102 {
103 	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
104 }
105 
106 
107 static inline BOOL
108 isspace(char c)
109 {
110 	return c == ' ' || c == '\t' || c == '\n' || c == '\12';
111 }
112 
113 static inline BOOL
114 isdigit(char c)
115 {
116 	return c >= '0' && c <= '9';
117 }
118 
119 /*
120  * Convert a string to a long integer.
121  *
122  * Ignores `locale' stuff.  Assumes that the upper and lower case
123  * alphabets and digits are each contiguous.
124  */
125 long
126 strtol(const char *nptr, char **endptr, int base)
127 {
128 	const char *s = nptr;
129 	unsigned long acc;
130 	char c;
131 	unsigned long cutoff;
132 	int neg = 0, any, cutlim;
133 
134 	/*
135 	 * Skip white space and pick up leading +/- sign if any.
136 	 * If base is 0, allow 0x for hex and 0 for octal, else
137 	 * assume decimal; if base is already 16, allow 0x.
138 	 */
139 	do {
140 		c = *s++;
141 	} while (isspace(c));
142 	if (c == '-') {
143 		neg = 1;
144 		c = *s++;
145 	} else if (c == '+') {
146 		c = *s++;
147 	}
148 	if ((base == 0 || base == 16) &&
149 	    c == '0' && (*s == 'x' || *s == 'X')) {
150 		c = s[1];
151 		s += 2;
152 		base = 16;
153 	} else if ((base == 0 || base == 2) &&
154 	    c == '0' && (*s == 'b' || *s == 'B')) {
155 		c = s[1];
156 		s += 2;
157 		base = 2;
158 	}
159 	if (base == 0) {
160 		base = c == '0' ? 8 : 10;
161 	}
162 
163 	/*
164 	 * Compute the cutoff value between legal numbers and illegal
165 	 * numbers.  That is the largest legal value, divided by the
166 	 * base.  An input number that is greater than this value, if
167 	 * followed by a legal input character, is too big.  One that
168 	 * is equal to this value may be valid or not; the limit
169 	 * between valid and invalid numbers is then based on the last
170 	 * digit.  For instance, if the range for longs is
171 	 * [-2147483648..2147483647] and the input base is 10,
172 	 * cutoff will be set to 214748364 and cutlim to either
173 	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
174 	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
175 	 * the number is too big, and we will return a range error.
176 	 *
177 	 * Set any if any `digits' consumed; make it negative to indicate
178 	 * overflow.
179 	 */
180 	cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
181 	cutlim = ((int)(cutoff % (unsigned long)base));
182 	cutoff /= (unsigned long)base;
183 	for (acc = 0, any = 0;; c = *s++) {
184 		if (isdigit(c)) {
185 			c -= '0';
186 		} else if (isalpha(c)) {
187 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
188 		} else {
189 			break;
190 		}
191 		if (c >= base) {
192 			break;
193 		}
194 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) {
195 			any = -1;
196 		} else {
197 			any = 1;
198 			acc *= base;
199 			acc += c;
200 		}
201 	}
202 	if (any < 0) {
203 		acc = neg ? LONG_MIN : LONG_MAX;
204 //		errno = ERANGE;
205 	} else if (neg) {
206 		acc = -acc;
207 	}
208 	if (endptr != 0) {
209 		if (any) {
210 			*endptr = __CAST_AWAY_QUALIFIER(s - 1, const, char *);
211 		} else {
212 			*endptr = __CAST_AWAY_QUALIFIER(nptr, const, char *);
213 		}
214 	}
215 	return acc;
216 }
217 
218 unsigned long
219 strtoul(const char *nptr, char **endptr, int base)
220 {
221 	const char *s = nptr;
222 	unsigned long acc;
223 	char c;
224 	unsigned long cutoff;
225 	int neg = 0, any, cutlim;
226 
227 	/*
228 	 * See strtol for comments as to the logic used.
229 	 */
230 	do {
231 		c = *s++;
232 	} while (isspace(c));
233 	if (c == '-') {
234 		neg = 1;
235 		c = *s++;
236 	} else if (c == '+') {
237 		c = *s++;
238 	}
239 	if ((base == 0 || base == 16) &&
240 	    c == '0' && (*s == 'x' || *s == 'X')) {
241 		c = s[1];
242 		s += 2;
243 		base = 16;
244 	} else if ((base == 0 || base == 2) &&
245 	    c == '0' && (*s == 'b' || *s == 'B')) {
246 		c = s[1];
247 		s += 2;
248 		base = 2;
249 	}
250 	if (base == 0) {
251 		base = c == '0' ? 8 : 10;
252 	}
253 	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
254 	cutlim = ((int)((unsigned long)ULONG_MAX % (unsigned long)base));
255 	for (acc = 0, any = 0;; c = *s++) {
256 		if (isdigit(c)) {
257 			c -= '0';
258 		} else if (isalpha(c)) {
259 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
260 		} else {
261 			break;
262 		}
263 		if (c >= base) {
264 			break;
265 		}
266 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) {
267 			any = -1;
268 		} else {
269 			any = 1;
270 			acc *= base;
271 			acc += c;
272 		}
273 	}
274 	if (any < 0) {
275 		acc = ULONG_MAX;
276 //		errno = ERANGE;
277 	} else if (neg) {
278 		acc = -acc;
279 	}
280 	if (endptr != 0) {
281 		if (any) {
282 			*endptr = __CAST_AWAY_QUALIFIER(s - 1, const, char *);
283 		} else {
284 			*endptr = __CAST_AWAY_QUALIFIER(nptr, const, char *);
285 		}
286 	}
287 
288 	return acc;
289 }
290 
291 /*
292  * Convert a string to a quad integer.
293  *
294  * Ignores `locale' stuff.  Assumes that the upper and lower case
295  * alphabets and digits are each contiguous.
296  */
297 quad_t
298 strtoq(const char *nptr, char **endptr, int base)
299 {
300 	const char *s;
301 	u_quad_t acc;
302 	char c;
303 	u_quad_t qbase, cutoff;
304 	int neg, any, cutlim;
305 
306 	/*
307 	 * Skip white space and pick up leading +/- sign if any.
308 	 * If base is 0, allow 0x for hex and 0 for octal, else
309 	 * assume decimal; if base is already 16, allow 0x.
310 	 */
311 	s = nptr;
312 	do {
313 		c = *s++;
314 	} while (isspace(c));
315 	if (c == '-') {
316 		neg = 1;
317 		c = *s++;
318 	} else {
319 		neg = 0;
320 		if (c == '+') {
321 			c = *s++;
322 		}
323 	}
324 	if ((base == 0 || base == 16) &&
325 	    c == '0' && (*s == 'x' || *s == 'X')) {
326 		c = s[1];
327 		s += 2;
328 		base = 16;
329 	}
330 	if (base == 0) {
331 		base = c == '0' ? 8 : 10;
332 	}
333 
334 	/*
335 	 * Compute the cutoff value between legal numbers and illegal
336 	 * numbers.  That is the largest legal value, divided by the
337 	 * base.  An input number that is greater than this value, if
338 	 * followed by a legal input character, is too big.  One that
339 	 * is equal to this value may be valid or not; the limit
340 	 * between valid and invalid numbers is then based on the last
341 	 * digit.  For instance, if the range for quads is
342 	 * [-9223372036854775808..9223372036854775807] and the input base
343 	 * is 10, cutoff will be set to 922337203685477580 and cutlim to
344 	 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
345 	 * accumulated a value > 922337203685477580, or equal but the
346 	 * next digit is > 7 (or 8), the number is too big, and we will
347 	 * return a range error.
348 	 *
349 	 * Set any if any `digits' consumed; make it negative to indicate
350 	 * overflow.
351 	 */
352 	qbase = (unsigned)base;
353 	cutoff = neg ? -(u_quad_t)QUAD_MIN : QUAD_MAX;
354 	cutlim = ((int)(cutoff % qbase));
355 	cutoff /= qbase;
356 	for (acc = 0, any = 0;; c = *s++) {
357 		if (isdigit(c)) {
358 			c -= '0';
359 		} else if (isalpha(c)) {
360 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
361 		} else {
362 			break;
363 		}
364 		if (c >= base) {
365 			break;
366 		}
367 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) {
368 			any = -1;
369 		} else {
370 			any = 1;
371 			acc *= qbase;
372 			acc += c;
373 		}
374 	}
375 	if (any < 0) {
376 		acc = neg ? QUAD_MIN : QUAD_MAX;
377 //		errno = ERANGE;
378 	} else if (neg) {
379 		acc = -acc;
380 	}
381 	if (endptr != 0) {
382 		if (any) {
383 			*endptr = __CAST_AWAY_QUALIFIER(s - 1, const, char *);
384 		} else {
385 			*endptr = __CAST_AWAY_QUALIFIER(nptr, const, char *);
386 		}
387 	}
388 
389 	return acc;
390 }
391 
392 
393 /*
394  * Convert a string to an unsigned quad integer.
395  *
396  * Ignores `locale' stuff.  Assumes that the upper and lower case
397  * alphabets and digits are each contiguous.
398  */
399 u_quad_t
400 strtouq(const char *nptr,
401     char **endptr,
402     int base)
403 {
404 	const char *s = nptr;
405 	u_quad_t acc;
406 	char c;
407 	u_quad_t qbase, cutoff;
408 	int neg, any, cutlim;
409 
410 	/*
411 	 * See strtoq for comments as to the logic used.
412 	 */
413 	s = nptr;
414 	do {
415 		c = *s++;
416 	} while (isspace(c));
417 	if (c == '-') {
418 		neg = 1;
419 		c = *s++;
420 	} else {
421 		neg = 0;
422 		if (c == '+') {
423 			c = *s++;
424 		}
425 	}
426 	if ((base == 0 || base == 16) &&
427 	    c == '0' && (*s == 'x' || *s == 'X')) {
428 		c = s[1];
429 		s += 2;
430 		base = 16;
431 	}
432 	if (base == 0) {
433 		base = c == '0' ? 8 : 10;
434 	}
435 	qbase = (unsigned)base;
436 	cutoff = (u_quad_t)UQUAD_MAX / qbase;
437 	cutlim = ((int)((u_quad_t)UQUAD_MAX % qbase));
438 	for (acc = 0, any = 0;; c = *s++) {
439 		if (isdigit(c)) {
440 			c -= '0';
441 		} else if (isalpha(c)) {
442 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
443 		} else {
444 			break;
445 		}
446 		if (c >= base) {
447 			break;
448 		}
449 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) {
450 			any = -1;
451 		} else {
452 			any = 1;
453 			acc *= qbase;
454 			acc += c;
455 		}
456 	}
457 	if (any < 0) {
458 		acc = UQUAD_MAX;
459 //		errno = ERANGE;
460 	} else if (neg) {
461 		acc = -acc;
462 	}
463 	if (endptr != 0) {
464 		if (any) {
465 			*endptr = __CAST_AWAY_QUALIFIER(s - 1, const, char *);
466 		} else {
467 			*endptr = __CAST_AWAY_QUALIFIER(nptr, const, char *);
468 		}
469 	}
470 
471 	return acc;
472 }
473 
474 
475 /*
476  *
477  */
478 
479 char *
480 strncat(char *s1, const char *s2, unsigned long n)
481 {
482 	if (n != 0) {
483 		char *d = s1;
484 		const char *s = s2;
485 
486 		while (*d != 0) {
487 			d++;
488 		}
489 		do {
490 			if ((*d = *s++) == '\0') {
491 				break;
492 			}
493 			d++;
494 		} while (--n != 0);
495 		*d = '\0';
496 	}
497 	return s1;
498 }
499