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1 /*	$OpenBSD: fnmatch.c,v 1.19 2015/08/01 18:11:08 millert Exp $	*/
2 
3 /* Copyright (c) 2011, VMware, Inc.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *     * Redistributions of source code must retain the above copyright
9  *       notice, this list of conditions and the following disclaimer.
10  *     * Redistributions in binary form must reproduce the above copyright
11  *       notice, this list of conditions and the following disclaimer in the
12  *       documentation and/or other materials provided with the distribution.
13  *     * Neither the name of the VMware, Inc. nor the names of its contributors
14  *       may be used to endorse or promote products derived from this software
15  *       without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL VMWARE, INC. OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 2008 Todd C. Miller <millert@openbsd.org>
31  *
32  * Permission to use, copy, modify, and distribute this software for any
33  * purpose with or without fee is hereby granted, provided that the above
34  * copyright notice and this permission notice appear in all copies.
35  *
36  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
37  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
38  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
39  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
41  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
42  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43  */
44 
45 /* Authored by William A. Rowe Jr. <wrowe; apache.org, vmware.com>, April 2011
46  *
47  * Derived from The Open Group Base Specifications Issue 7, IEEE Std 1003.1-2008
48  * as described in;
49  *   http://pubs.opengroup.org/onlinepubs/9699919799/functions/fnmatch.html
50  *
51  * Filename pattern matches defined in section 2.13, "Pattern Matching Notation"
52  * from chapter 2. "Shell Command Language"
53  *   http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_13
54  * where; 1. A bracket expression starting with an unquoted <circumflex> '^'
55  * character CONTINUES to specify a non-matching list; 2. an explicit <period> '.'
56  * in a bracket expression matching list, e.g. "[.abc]" does NOT match a leading
57  * <period> in a filename; 3. a <left-square-bracket> '[' which does not introduce
58  * a valid bracket expression is treated as an ordinary character; 4. a differing
59  * number of consecutive slashes within pattern and string will NOT match;
60  * 5. a trailing '\' in FNM_ESCAPE mode is treated as an ordinary '\' character.
61  *
62  * Bracket expansion defined in section 9.3.5, "RE Bracket Expression",
63  * from chapter 9, "Regular Expressions"
64  *   http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05
65  * with no support for collating symbols, equivalence class expressions or
66  * character class expressions.  A partial range expression with a leading
67  * hyphen following a valid range expression will match only the ordinary
68  * <hyphen> and the ending character (e.g. "[a-m-z]" will match characters
69  * 'a' through 'm', a <hyphen> '-', or a 'z').
70  *
71  * Supports BSD extensions FNM_LEADING_DIR to match pattern to the end of one
72  * path segment of string, and FNM_CASEFOLD to ignore alpha case.
73  *
74  * NOTE: Only POSIX/C single byte locales are correctly supported at this time.
75  * Notably, non-POSIX locales with FNM_CASEFOLD produce undefined results,
76  * particularly in ranges of mixed case (e.g. "[A-z]") or spanning alpha and
77  * nonalpha characters within a range.
78  *
79  * XXX comments below indicate porting required for multi-byte character sets
80  * and non-POSIX locale collation orders; requires mbr* APIs to track shift
81  * state of pattern and string (rewinding pattern and string repeatedly).
82  *
83  * Certain parts of the code assume 0x00-0x3F are unique with any MBCS (e.g.
84  * UTF-8, SHIFT-JIS, etc).  Any implementation allowing '\' as an alternate
85  * path delimiter must be aware that 0x5C is NOT unique within SHIFT-JIS.
86  */
87 
88 #include <fnmatch.h>
89 #include <string.h>
90 #include <ctype.h>
91 
92 #include "charclass.h"
93 
94 #define	RANGE_MATCH	1
95 #define	RANGE_NOMATCH	0
96 #define	RANGE_ERROR	(-1)
97 
98 static int
classmatch(const char * pattern,char test,int foldcase,const char ** ep)99 classmatch(const char *pattern, char test, int foldcase, const char **ep)
100 {
101 	struct cclass *cc;
102 	const char *colon;
103 	size_t len;
104 	int rval = RANGE_NOMATCH;
105 	const char * const mismatch = pattern;
106 
107 	if (*pattern != '[' || pattern[1] != ':') {
108 		*ep = mismatch;
109 		return(RANGE_ERROR);
110 	}
111 
112 	pattern += 2;
113 
114 	if ((colon = strchr(pattern, ':')) == NULL || colon[1] != ']') {
115 		*ep = mismatch;
116 		return(RANGE_ERROR);
117 	}
118 	*ep = colon + 2;
119 	len = (size_t)(colon - pattern);
120 
121 	if (foldcase && strncmp(pattern, "upper:]", 7) == 0)
122 		pattern = "lower:]";
123 	for (cc = cclasses; cc->name != NULL; cc++) {
124 		if (!strncmp(pattern, cc->name, len) && cc->name[len] == '\0') {
125 			if (cc->isctype((unsigned char)test))
126 				rval = RANGE_MATCH;
127 			break;
128 		}
129 	}
130 	if (cc->name == NULL) {
131 		/* invalid character class, treat as normal text */
132 		*ep = mismatch;
133 		rval = RANGE_ERROR;
134 	}
135 	return(rval);
136 }
137 
138 /* Most MBCS/collation/case issues handled here.  Wildcard '*' is not handled.
139  * EOS '\0' and the FNM_PATHNAME '/' delimiters are not advanced over,
140  * however the "\/" sequence is advanced to '/'.
141  *
142  * Both pattern and string are **char to support pointer increment of arbitrary
143  * multibyte characters for the given locale, in a later iteration of this code
144  */
fnmatch_ch(const char ** pattern,const char ** string,int flags)145 static int fnmatch_ch(const char **pattern, const char **string, int flags)
146 {
147     const char * const mismatch = *pattern;
148     const int nocase = !!(flags & FNM_CASEFOLD);
149     const int escape = !(flags & FNM_NOESCAPE);
150     const int slash = !!(flags & FNM_PATHNAME);
151     int result = FNM_NOMATCH;
152     const char *startch;
153     int negate;
154 
155     if (**pattern == '[')
156     {
157         ++*pattern;
158 
159         /* Handle negation, either leading ! or ^ operators (never both) */
160         negate = ((**pattern == '!') || (**pattern == '^'));
161         if (negate)
162             ++*pattern;
163 
164         /* ']' is an ordinary character at the start of the range pattern */
165         if (**pattern == ']')
166             goto leadingclosebrace;
167 
168         while (**pattern)
169         {
170             if (**pattern == ']') {
171                 ++*pattern;
172                 /* XXX: Fix for MBCS character width */
173                 ++*string;
174                 return (result ^ negate);
175             }
176 
177             if (escape && (**pattern == '\\')) {
178                 ++*pattern;
179 
180                 /* Patterns must be terminated with ']', not EOS */
181                 if (!**pattern)
182                     break;
183             }
184 
185             /* Patterns must be terminated with ']' not '/' */
186             if (slash && (**pattern == '/'))
187                 break;
188 
189             /* Match character classes. */
190             if (classmatch(*pattern, **string, nocase, pattern)
191                 == RANGE_MATCH) {
192                 result = 0;
193                 continue;
194             }
195             if (!**pattern)
196                 break;
197 
198 leadingclosebrace:
199             /* Look at only well-formed range patterns;
200              * "x-]" is not allowed unless escaped ("x-\]")
201              * XXX: Fix for locale/MBCS character width
202              */
203             if (((*pattern)[1] == '-') && ((*pattern)[2] != ']'))
204             {
205                 startch = *pattern;
206                 *pattern += (escape && ((*pattern)[2] == '\\')) ? 3 : 2;
207 
208                 /* NOT a properly balanced [expr] pattern, EOS terminated
209                  * or ranges containing a slash in FNM_PATHNAME mode pattern
210                  * fall out to to the rewind and test '[' literal code path
211                  */
212                 if (!**pattern || (slash && (**pattern == '/')))
213                     break;
214 
215                 /* XXX: handle locale/MBCS comparison, advance by MBCS char width */
216                 if ((**string >= *startch) && (**string <= **pattern))
217                     result = 0;
218                 else if (nocase && (isupper((unsigned char)**string) ||
219 			    isupper((unsigned char)*startch) ||
220                             isupper((unsigned char)**pattern))
221                             && (tolower((unsigned char)**string) >=
222 			        tolower((unsigned char)*startch))
223                             && (tolower((unsigned char)**string) <=
224 				tolower((unsigned char)**pattern)))
225                     result = 0;
226 
227                 ++*pattern;
228                 continue;
229             }
230 
231             /* XXX: handle locale/MBCS comparison, advance by MBCS char width */
232             if ((**string == **pattern))
233                 result = 0;
234             else if (nocase && (isupper((unsigned char)**string) ||
235 			    isupper((unsigned char)**pattern))
236                             && (tolower((unsigned char)**string) ==
237 				tolower((unsigned char)**pattern)))
238                 result = 0;
239 
240             ++*pattern;
241         }
242 
243         /* NOT a properly balanced [expr] pattern; Rewind
244          * and reset result to test '[' literal
245          */
246         *pattern = mismatch;
247         result = FNM_NOMATCH;
248     }
249     else if (**pattern == '?') {
250         /* Optimize '?' match before unescaping **pattern */
251         if (!**string || (slash && (**string == '/')))
252             return FNM_NOMATCH;
253         result = 0;
254         goto fnmatch_ch_success;
255     }
256     else if (escape && (**pattern == '\\') && (*pattern)[1]) {
257         ++*pattern;
258     }
259 
260     /* XXX: handle locale/MBCS comparison, advance by the MBCS char width */
261     if (**string == **pattern)
262         result = 0;
263     else if (nocase && (isupper((unsigned char)**string) ||
264 		    isupper((unsigned char)**pattern))
265                     && (tolower((unsigned char)**string) ==
266 			tolower((unsigned char)**pattern)))
267         result = 0;
268 
269     /* Refuse to advance over trailing slash or nulls
270      */
271     if (!**string || !**pattern || (slash && ((**string == '/') || (**pattern == '/'))))
272         return result;
273 
274 fnmatch_ch_success:
275     ++*pattern;
276     ++*string;
277     return result;
278 }
279 
280 
fnmatch(const char * pattern,const char * string,int flags)281 int fnmatch(const char *pattern, const char *string, int flags)
282 {
283     static const char dummystring[2] = {' ', 0};
284     const int escape = !(flags & FNM_NOESCAPE);
285     const int slash = !!(flags & FNM_PATHNAME);
286     const int leading_dir = !!(flags & FNM_LEADING_DIR);
287     const char *strendseg;
288     const char *dummyptr;
289     const char *matchptr;
290     int wild;
291     /* For '*' wild processing only; surpress 'used before initialization'
292      * warnings with dummy initialization values;
293      */
294     const char *strstartseg = NULL;
295     const char *mismatch = NULL;
296     int matchlen = 0;
297 
298     if (*pattern == '*')
299         goto firstsegment;
300 
301     while (*pattern && *string)
302     {
303         /* Pre-decode "\/" which has no special significance, and
304          * match balanced slashes, starting a new segment pattern
305          */
306         if (slash && escape && (*pattern == '\\') && (pattern[1] == '/'))
307             ++pattern;
308         if (slash && (*pattern == '/') && (*string == '/')) {
309             ++pattern;
310             ++string;
311         }
312 
313 firstsegment:
314         /* At the beginning of each segment, validate leading period behavior.
315          */
316         if ((flags & FNM_PERIOD) && (*string == '.'))
317         {
318             if (*pattern == '.')
319                 ++pattern;
320             else if (escape && (*pattern == '\\') && (pattern[1] == '.'))
321                 pattern += 2;
322             else
323                 return FNM_NOMATCH;
324             ++string;
325         }
326 
327         /* Determine the end of string segment
328          *
329          * Presumes '/' character is unique, not composite in any MBCS encoding
330          */
331         if (slash) {
332             strendseg = strchr(string, '/');
333             if (!strendseg)
334                 strendseg = strchr(string, '\0');
335         }
336         else {
337             strendseg = strchr(string, '\0');
338         }
339 
340         /* Allow pattern '*' to be consumed even with no remaining string to match
341          */
342         while (*pattern)
343         {
344             if ((string > strendseg)
345                 || ((string == strendseg) && (*pattern != '*')))
346                 break;
347 
348             if (slash && ((*pattern == '/')
349                            || (escape && (*pattern == '\\')
350                                       && (pattern[1] == '/'))))
351                 break;
352 
353             /* Reduce groups of '*' and '?' to n '?' matches
354              * followed by one '*' test for simplicity
355              */
356             for (wild = 0; ((*pattern == '*') || (*pattern == '?')); ++pattern)
357             {
358                 if (*pattern == '*') {
359                     wild = 1;
360                 }
361                 else if (string < strendseg) {  /* && (*pattern == '?') */
362                     /* XXX: Advance 1 char for MBCS locale */
363                     ++string;
364                 }
365                 else {  /* (string >= strendseg) && (*pattern == '?') */
366                     return FNM_NOMATCH;
367                 }
368             }
369 
370             if (wild)
371             {
372                 strstartseg = string;
373                 mismatch = pattern;
374 
375                 /* Count fixed (non '*') char matches remaining in pattern
376                  * excluding '/' (or "\/") and '*'
377                  */
378                 for (matchptr = pattern, matchlen = 0; 1; ++matchlen)
379                 {
380                     if ((*matchptr == '\0')
381                         || (slash && ((*matchptr == '/')
382                                       || (escape && (*matchptr == '\\')
383                                                  && (matchptr[1] == '/')))))
384                     {
385                         /* Compare precisely this many trailing string chars,
386                          * the resulting match needs no wildcard loop
387                          */
388                         /* XXX: Adjust for MBCS */
389                         if (string + matchlen > strendseg)
390                             return FNM_NOMATCH;
391 
392                         string = strendseg - matchlen;
393                         wild = 0;
394                         break;
395                     }
396 
397                     if (*matchptr == '*')
398                     {
399                         /* Ensure at least this many trailing string chars remain
400                          * for the first comparison
401                          */
402                         /* XXX: Adjust for MBCS */
403                         if (string + matchlen > strendseg)
404                             return FNM_NOMATCH;
405 
406                         /* Begin first wild comparison at the current position */
407                         break;
408                     }
409 
410                     /* Skip forward in pattern by a single character match
411                      * Use a dummy fnmatch_ch() test to count one "[range]" escape
412                      */
413                     /* XXX: Adjust for MBCS */
414                     if (escape && (*matchptr == '\\') && matchptr[1]) {
415                         matchptr += 2;
416                     }
417                     else if (*matchptr == '[') {
418                         dummyptr = dummystring;
419                         fnmatch_ch(&matchptr, &dummyptr, flags);
420                     }
421                     else {
422                         ++matchptr;
423                     }
424                 }
425             }
426 
427             /* Incrementally match string against the pattern
428              */
429             while (*pattern && (string < strendseg))
430             {
431                 /* Success; begin a new wild pattern search
432                  */
433                 if (*pattern == '*')
434                     break;
435 
436                 if (slash && ((*string == '/')
437                               || (*pattern == '/')
438                               || (escape && (*pattern == '\\')
439                                          && (pattern[1] == '/'))))
440                     break;
441 
442                 /* Compare ch's (the pattern is advanced over "\/" to the '/',
443                  * but slashes will mismatch, and are not consumed)
444                  */
445                 if (!fnmatch_ch(&pattern, &string, flags))
446                     continue;
447 
448                 /* Failed to match, loop against next char offset of string segment
449                  * until not enough string chars remain to match the fixed pattern
450                  */
451                 if (wild) {
452                     /* XXX: Advance 1 char for MBCS locale */
453                     string = ++strstartseg;
454                     if (string + matchlen > strendseg)
455                         return FNM_NOMATCH;
456 
457                     pattern = mismatch;
458                     continue;
459                 }
460                 else
461                     return FNM_NOMATCH;
462             }
463         }
464 
465         if (*string && !((slash || leading_dir) && (*string == '/')))
466             return FNM_NOMATCH;
467 
468         if (*pattern && !(slash && ((*pattern == '/')
469                                     || (escape && (*pattern == '\\')
470                                                && (pattern[1] == '/')))))
471             return FNM_NOMATCH;
472 
473         if (leading_dir && !*pattern && *string == '/')
474             return 0;
475     }
476 
477     /* Where both pattern and string are at EOS, declare success
478      */
479     if (!*string && !*pattern)
480         return 0;
481 
482     /* pattern didn't match to the end of string */
483     return FNM_NOMATCH;
484 }
485