1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33
34__FBSDID("$FreeBSD$");
35
36#ifndef lint
37static const char sccsid[] = "@(#)str.c	8.2 (Berkeley) 4/28/95";
38#endif
39
40#include <sys/types.h>
41
42#include <ctype.h>
43#include <err.h>
44#include <errno.h>
45#include <stddef.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49#include <wchar.h>
50#include <wctype.h>
51
52#include "extern.h"
53
54static int      backslash(STR *, int *);
55static int	bracket(STR *);
56static void	genclass(STR *);
57static void	genequiv(STR *);
58static int      genrange(STR *, int);
59static void	genseq(STR *);
60
61wint_t
62next(STR *s)
63{
64	int is_octal;
65	wint_t ch;
66	wchar_t wch;
67	size_t clen;
68
69	switch (s->state) {
70	case EOS:
71		return (0);
72	case INFINITE:
73		return (1);
74	case NORMAL:
75		switch (*s->str) {
76		case '\0':
77			s->state = EOS;
78			return (0);
79		case '\\':
80			s->lastch = backslash(s, &is_octal);
81			break;
82		case '[':
83			if (bracket(s))
84				return (next(s));
85			/* FALLTHROUGH */
86		default:
87			clen = mbrtowc(&wch, s->str, MB_LEN_MAX, NULL);
88			if (clen == (size_t)-1 || clen == (size_t)-2 ||
89			    clen == 0)
90				errc(1, EILSEQ, NULL);
91			is_octal = 0;
92			s->lastch = wch;
93			s->str += clen;
94			break;
95		}
96
97		/* We can start a range at any time. */
98		if (s->str[0] == '-' && genrange(s, is_octal))
99			return (next(s));
100		return (1);
101	case RANGE:
102		if (s->cnt-- == 0) {
103			s->state = NORMAL;
104			return (next(s));
105		}
106		++s->lastch;
107		return (1);
108	case SEQUENCE:
109		if (s->cnt-- == 0) {
110			s->state = NORMAL;
111			return (next(s));
112		}
113		return (1);
114	case CCLASS:
115	case CCLASS_UPPER:
116	case CCLASS_LOWER:
117		s->cnt++;
118		ch = nextwctype(s->lastch, s->cclass);
119		if (ch == -1) {
120			s->state = NORMAL;
121			return (next(s));
122		}
123		s->lastch = ch;
124		return (1);
125	case SET:
126		if ((ch = s->set[s->cnt++]) == OOBCH) {
127			s->state = NORMAL;
128			return (next(s));
129		}
130		s->lastch = ch;
131		return (1);
132	default:
133		return (0);
134	}
135	/* NOTREACHED */
136}
137
138static int
139bracket(STR *s)
140{
141	char *p;
142
143	switch (s->str[1]) {
144	case ':':				/* "[:class:]" */
145		if ((p = strchr(s->str + 2, ']')) == NULL)
146			return (0);
147		if (*(p - 1) != ':' || p - s->str < 4)
148			goto repeat;
149		*(p - 1) = '\0';
150		s->str += 2;
151		genclass(s);
152		s->str = p + 1;
153		return (1);
154	case '=':				/* "[=equiv=]" */
155		if (s->str[2] == '\0' || (p = strchr(s->str + 3, ']')) == NULL)
156			return (0);
157		if (*(p - 1) != '=' || p - s->str < 4)
158			goto repeat;
159		s->str += 2;
160		genequiv(s);
161		return (1);
162	default:				/* "[\###*n]" or "[#*n]" */
163	repeat:
164		if ((p = strpbrk(s->str + 2, "*]")) == NULL)
165			return (0);
166		if (p[0] != '*' || strchr(p, ']') == NULL)
167			return (0);
168		s->str += 1;
169		genseq(s);
170		return (1);
171	}
172	/* NOTREACHED */
173}
174
175static void
176genclass(STR *s)
177{
178
179	if ((s->cclass = wctype(s->str)) == 0)
180		errx(1, "unknown class %s", s->str);
181	s->cnt = 0;
182	s->lastch = -1;		/* incremented before check in next() */
183	if (strcmp(s->str, "upper") == 0)
184		s->state = CCLASS_UPPER;
185	else if (strcmp(s->str, "lower") == 0)
186		s->state = CCLASS_LOWER;
187	else
188		s->state = CCLASS;
189}
190
191static void
192genequiv(STR *s)
193{
194	int i, p, pri;
195	char src[2], dst[3];
196	size_t clen;
197	wchar_t wc;
198
199	if (*s->str == '\\') {
200		s->equiv[0] = backslash(s, NULL);
201		if (*s->str != '=')
202			errx(1, "misplaced equivalence equals sign");
203		s->str += 2;
204	} else {
205		clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
206		if (clen == (size_t)-1 || clen == (size_t)-2 || clen == 0)
207			errc(1, EILSEQ, NULL);
208		s->equiv[0] = wc;
209		if (s->str[clen] != '=')
210			errx(1, "misplaced equivalence equals sign");
211		s->str += clen + 2;
212	}
213
214	/*
215	 * Calculate the set of all characters in the same equivalence class
216	 * as the specified character (they will have the same primary
217	 * collation weights).
218	 * XXX Knows too much about how strxfrm() is implemented. Assumes
219	 * it fills the string with primary collation weight bytes. Only one-
220	 * to-one mappings are supported.
221	 * XXX Equivalence classes not supported in multibyte locales.
222	 */
223	src[0] = (char)s->equiv[0];
224	src[1] = '\0';
225	if (MB_CUR_MAX == 1 && strxfrm(dst, src, sizeof(dst)) == 1) {
226		pri = (unsigned char)*dst;
227		for (p = 1, i = 1; i < NCHARS_SB; i++) {
228			*src = i;
229			if (strxfrm(dst, src, sizeof(dst)) == 1 && pri &&
230			    pri == (unsigned char)*dst)
231				s->equiv[p++] = i;
232		}
233		s->equiv[p] = OOBCH;
234	}
235
236	s->cnt = 0;
237	s->state = SET;
238	s->set = s->equiv;
239}
240
241static int
242genrange(STR *s, int was_octal)
243{
244	int stopval, octal;
245	char *savestart;
246	int n, cnt, *p;
247	size_t clen;
248	wchar_t wc;
249
250	octal = 0;
251	savestart = s->str;
252	if (*++s->str == '\\')
253		stopval = backslash(s, &octal);
254	else {
255		clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
256		if (clen == (size_t)-1 || clen == (size_t)-2)
257			errc(1, EILSEQ, NULL);
258		stopval = wc;
259		s->str += clen;
260	}
261	/*
262	 * XXX Characters are not ordered according to collating sequence in
263	 * multibyte locales.
264	 */
265	if (octal || was_octal || MB_CUR_MAX > 1) {
266		if (stopval < s->lastch) {
267			s->str = savestart;
268			return (0);
269		}
270		s->cnt = stopval - s->lastch + 1;
271		s->state = RANGE;
272		--s->lastch;
273		return (1);
274	}
275	if (charcoll((const void *)&stopval, (const void *)&(s->lastch)) < 0) {
276		s->str = savestart;
277		return (0);
278	}
279	if ((s->set = p = malloc((NCHARS_SB + 1) * sizeof(int))) == NULL)
280		err(1, "genrange() malloc");
281	for (cnt = 0; cnt < NCHARS_SB; cnt++)
282		if (charcoll((const void *)&cnt, (const void *)&(s->lastch)) >= 0 &&
283		    charcoll((const void *)&cnt, (const void *)&stopval) <= 0)
284			*p++ = cnt;
285	*p = OOBCH;
286	n = p - s->set;
287
288	s->cnt = 0;
289	s->state = SET;
290	if (n > 1)
291		mergesort(s->set, n, sizeof(*(s->set)), charcoll);
292	return (1);
293}
294
295static void
296genseq(STR *s)
297{
298	char *ep;
299	wchar_t wc;
300	size_t clen;
301
302	if (s->which == STRING1)
303		errx(1, "sequences only valid in string2");
304
305	if (*s->str == '\\')
306		s->lastch = backslash(s, NULL);
307	else {
308		clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
309		if (clen == (size_t)-1 || clen == (size_t)-2)
310			errc(1, EILSEQ, NULL);
311		s->lastch = wc;
312		s->str += clen;
313	}
314	if (*s->str != '*')
315		errx(1, "misplaced sequence asterisk");
316
317	switch (*++s->str) {
318	case '\\':
319		s->cnt = backslash(s, NULL);
320		break;
321	case ']':
322		s->cnt = 0;
323		++s->str;
324		break;
325	default:
326		if (isdigit((u_char)*s->str)) {
327			s->cnt = strtol(s->str, &ep, 0);
328			if (*ep == ']') {
329				s->str = ep + 1;
330				break;
331			}
332		}
333		errx(1, "illegal sequence count");
334		/* NOTREACHED */
335	}
336
337	s->state = s->cnt ? SEQUENCE : INFINITE;
338}
339
340/*
341 * Translate \??? into a character.  Up to 3 octal digits, if no digits either
342 * an escape code or a literal character.
343 */
344static int
345backslash(STR *s, int *is_octal)
346{
347	int ch, cnt, val;
348
349	if (is_octal != NULL)
350		*is_octal = 0;
351	for (cnt = val = 0;;) {
352		ch = (u_char)*++s->str;
353		if (!isdigit(ch) || ch > '7')
354			break;
355		val = val * 8 + ch - '0';
356		if (++cnt == 3) {
357			++s->str;
358			break;
359		}
360	}
361	if (cnt) {
362		if (is_octal != NULL)
363			*is_octal = 1;
364		return (val);
365	}
366	if (ch != '\0')
367		++s->str;
368	switch (ch) {
369		case 'a':			/* escape characters */
370			return ('\7');
371		case 'b':
372			return ('\b');
373		case 'f':
374			return ('\f');
375		case 'n':
376			return ('\n');
377		case 'r':
378			return ('\r');
379		case 't':
380			return ('\t');
381		case 'v':
382			return ('\13');
383		case '\0':			/*  \" -> \ */
384			s->state = EOS;
385			return ('\\');
386		default:			/* \x" -> x */
387			return (ch);
388	}
389}
390