1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Guido van Rossum.
9 *
10 * Copyright (c) 2011 The FreeBSD Foundation
11 *
12 * Portions of this software were developed by David Chisnall
13 * under sponsorship from the FreeBSD Foundation.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 *    notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 *    notice, this list of conditions and the following disclaimer in the
22 *    documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40/*
41 * Function fnmatch() as specified in POSIX 1003.2-1992, section B.6.
42 * Compares a filename or pathname to a pattern.
43 */
44
45/*
46 * Some notes on multibyte character support:
47 * 1. Patterns with illegal byte sequences match nothing.
48 * 2. Illegal byte sequences in the "string" argument are handled by treating
49 *    them as single-byte characters with a value of the first byte of the
50 *    sequence cast to wchar_t.
51 * 3. Multibyte conversion state objects (mbstate_t) are passed around and
52 *    used for most, but not all, conversions. Further work will be required
53 *    to support state-dependent encodings.
54 */
55
56#include <fnmatch.h>
57#include <limits.h>
58#include <string.h>
59#include <wchar.h>
60#include <wctype.h>
61
62#include "collate.h"
63
64#define	EOS	'\0'
65
66#define RANGE_MATCH     1
67#define RANGE_NOMATCH   0
68#define RANGE_ERROR     (-1)
69
70static int rangematch(const char *, wchar_t, int, char **, mbstate_t *);
71static int fnmatch1(const char *, const char *, const char *, int, mbstate_t,
72		mbstate_t);
73
74int
75fnmatch(const char *pattern, const char *string, int flags)
76{
77	static const mbstate_t initial;
78
79	return (fnmatch1(pattern, string, string, flags, initial, initial));
80}
81
82static int
83fnmatch1(const char *pattern, const char *string, const char *stringstart,
84    int flags, mbstate_t patmbs, mbstate_t strmbs)
85{
86	const char *bt_pattern, *bt_string;
87	mbstate_t bt_patmbs, bt_strmbs;
88	char *newp;
89	char c;
90	wchar_t pc, sc;
91	size_t pclen, sclen;
92
93	bt_pattern = bt_string = NULL;
94	for (;;) {
95		pclen = mbrtowc(&pc, pattern, MB_LEN_MAX, &patmbs);
96		if (pclen == (size_t)-1 || pclen == (size_t)-2)
97			return (FNM_NOMATCH);
98		pattern += pclen;
99		sclen = mbrtowc(&sc, string, MB_LEN_MAX, &strmbs);
100		if (sclen == (size_t)-1 || sclen == (size_t)-2) {
101			sc = (unsigned char)*string;
102			sclen = 1;
103			memset(&strmbs, 0, sizeof(strmbs));
104		}
105		switch (pc) {
106		case EOS:
107			if ((flags & FNM_LEADING_DIR) && sc == '/')
108				return (0);
109			if (sc == EOS)
110				return (0);
111			goto backtrack;
112		case '?':
113			if (sc == EOS)
114				return (FNM_NOMATCH);
115			if (sc == '/' && (flags & FNM_PATHNAME))
116				goto backtrack;
117			if (sc == '.' && (flags & FNM_PERIOD) &&
118			    (string == stringstart ||
119			    ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
120				goto backtrack;
121			string += sclen;
122			break;
123		case '*':
124			c = *pattern;
125			/* Collapse multiple stars. */
126			while (c == '*')
127				c = *++pattern;
128
129			if (sc == '.' && (flags & FNM_PERIOD) &&
130			    (string == stringstart ||
131			    ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
132				goto backtrack;
133
134			/* Optimize for pattern with * at end or before /. */
135			if (c == EOS)
136				if (flags & FNM_PATHNAME)
137					return ((flags & FNM_LEADING_DIR) ||
138					    strchr(string, '/') == NULL ?
139					    0 : FNM_NOMATCH);
140				else
141					return (0);
142			else if (c == '/' && flags & FNM_PATHNAME) {
143				if ((string = strchr(string, '/')) == NULL)
144					return (FNM_NOMATCH);
145				break;
146			}
147
148			/*
149			 * First try the shortest match for the '*' that
150			 * could work. We can forget any earlier '*' since
151			 * there is no way having it match more characters
152			 * can help us, given that we are already here.
153			 */
154			bt_pattern = pattern, bt_patmbs = patmbs;
155			bt_string = string, bt_strmbs = strmbs;
156			break;
157		case '[':
158			if (sc == EOS)
159				return (FNM_NOMATCH);
160			if (sc == '/' && (flags & FNM_PATHNAME))
161				goto backtrack;
162			if (sc == '.' && (flags & FNM_PERIOD) &&
163			    (string == stringstart ||
164			    ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
165				goto backtrack;
166
167			switch (rangematch(pattern, sc, flags, &newp,
168			    &patmbs)) {
169			case RANGE_ERROR:
170				goto norm;
171			case RANGE_MATCH:
172				pattern = newp;
173				break;
174			case RANGE_NOMATCH:
175				goto backtrack;
176			}
177			string += sclen;
178			break;
179		case '\\':
180			if (!(flags & FNM_NOESCAPE)) {
181				pclen = mbrtowc(&pc, pattern, MB_LEN_MAX,
182				    &patmbs);
183				if (pclen == 0 || pclen == (size_t)-1 ||
184				    pclen == (size_t)-2)
185					return (FNM_NOMATCH);
186				pattern += pclen;
187			}
188			/* FALLTHROUGH */
189		default:
190		norm:
191			string += sclen;
192			if (pc == sc)
193				;
194			else if ((flags & FNM_CASEFOLD) &&
195				 (towlower(pc) == towlower(sc)))
196				;
197			else {
198		backtrack:
199				/*
200				 * If we have a mismatch (other than hitting
201				 * the end of the string), go back to the last
202				 * '*' seen and have it match one additional
203				 * character.
204				 */
205				if (bt_pattern == NULL)
206					return (FNM_NOMATCH);
207				sclen = mbrtowc(&sc, bt_string, MB_LEN_MAX,
208				    &bt_strmbs);
209				if (sclen == (size_t)-1 ||
210				    sclen == (size_t)-2) {
211					sc = (unsigned char)*bt_string;
212					sclen = 1;
213					memset(&bt_strmbs, 0,
214					    sizeof(bt_strmbs));
215				}
216				if (sc == EOS)
217					return (FNM_NOMATCH);
218				if (sc == '/' && flags & FNM_PATHNAME)
219					return (FNM_NOMATCH);
220				bt_string += sclen;
221				pattern = bt_pattern, patmbs = bt_patmbs;
222				string = bt_string, strmbs = bt_strmbs;
223			}
224			break;
225		}
226	}
227	/* NOTREACHED */
228}
229
230static int
231rangematch(const char *pattern, wchar_t test, int flags, char **newp,
232    mbstate_t *patmbs)
233{
234	int negate, ok;
235	wchar_t c, c2;
236	size_t pclen;
237	const char *origpat;
238	struct xlocale_collate *table =
239		(struct xlocale_collate*)__get_locale()->components[XLC_COLLATE];
240
241	/*
242	 * A bracket expression starting with an unquoted circumflex
243	 * character produces unspecified results (IEEE 1003.2-1992,
244	 * 3.13.2).  This implementation treats it like '!', for
245	 * consistency with the regular expression syntax.
246	 * J.T. Conklin (conklin@ngai.kaleida.com)
247	 */
248	if ((negate = (*pattern == '!' || *pattern == '^')))
249		++pattern;
250
251	if (flags & FNM_CASEFOLD)
252		test = towlower(test);
253
254	/*
255	 * A right bracket shall lose its special meaning and represent
256	 * itself in a bracket expression if it occurs first in the list.
257	 * -- POSIX.2 2.8.3.2
258	 */
259	ok = 0;
260	origpat = pattern;
261	for (;;) {
262		if (*pattern == ']' && pattern > origpat) {
263			pattern++;
264			break;
265		} else if (*pattern == '\0') {
266			return (RANGE_ERROR);
267		} else if (*pattern == '/' && (flags & FNM_PATHNAME)) {
268			return (RANGE_NOMATCH);
269		} else if (*pattern == '\\' && !(flags & FNM_NOESCAPE))
270			pattern++;
271		pclen = mbrtowc(&c, pattern, MB_LEN_MAX, patmbs);
272		if (pclen == (size_t)-1 || pclen == (size_t)-2)
273			return (RANGE_NOMATCH);
274		pattern += pclen;
275
276		if (flags & FNM_CASEFOLD)
277			c = towlower(c);
278
279		if (*pattern == '-' && *(pattern + 1) != EOS &&
280		    *(pattern + 1) != ']') {
281			if (*++pattern == '\\' && !(flags & FNM_NOESCAPE))
282				if (*pattern != EOS)
283					pattern++;
284			pclen = mbrtowc(&c2, pattern, MB_LEN_MAX, patmbs);
285			if (pclen == (size_t)-1 || pclen == (size_t)-2)
286				return (RANGE_NOMATCH);
287			pattern += pclen;
288			if (c2 == EOS)
289				return (RANGE_ERROR);
290
291			if (flags & FNM_CASEFOLD)
292				c2 = towlower(c2);
293
294			if (table->__collate_load_error ?
295			    c <= test && test <= c2 :
296			       __wcollate_range_cmp(c, test) <= 0
297			    && __wcollate_range_cmp(test, c2) <= 0
298			   )
299				ok = 1;
300		} else if (c == test)
301			ok = 1;
302	}
303
304	*newp = (char *)pattern;
305	return (ok == negate ? RANGE_NOMATCH : RANGE_MATCH);
306}
307