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      1 /*	$NetBSD: pmatch.c,v 1.9 2024/10/09 23:16:03 gutteridge Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1980, 1991 The Regents of the University of California.
      5  * 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/param.h>
     33 
     34 /* So we can build this in userland for the tests in strlist.c */
     35 #if defined(_KERNEL) || defined(_STANDALONE)
     36 #include <lib/libkern/libkern.h>
     37 #else
     38 int pmatch(const char *, const char *, const char **);
     39 #endif
     40 
     41 /*
     42  * pmatch():
     43  *	Return 2 on exact match.
     44  *	Return 1 on substring match.
     45  *	Return 0 on no match.
     46  *	Return -1 on error.
     47  * *estr will point to the end of the longest exact or substring match.
     48  */
     49 int
     50 pmatch(const char *string, const char *pattern, const char **estr)
     51 {
     52 	u_char stringc, patternc, rangec;
     53 	int match, negate_range;
     54 	const char *oestr, *pestr, *testr = NULL;
     55 
     56 	if (estr == NULL)
     57 		estr = &testr;
     58 
     59 	for (;; ++string) {
     60 		stringc = *string;
     61 		switch (patternc = *pattern++) {
     62 		case 0:
     63 			*estr = string;
     64 			return stringc == '\0' ? 2 : 1;
     65 		case '?':
     66 			if (stringc == '\0')
     67 				return 0;
     68 			*estr = string;
     69 			break;
     70 		case '*':
     71 			if (!*pattern) {
     72 				while (*string)
     73 					string++;
     74 				*estr = string;
     75 				return 2;
     76 			}
     77 			oestr = *estr;
     78 			pestr = NULL;
     79 
     80 			do {
     81 				switch (pmatch(string, pattern, estr)) {
     82 				case -1:
     83 					return -1;
     84 				case 0:
     85 					break;
     86 				case 1:
     87 					pestr = *estr;
     88 					break;
     89 				case 2:
     90 					return 2;
     91 				default:
     92 					return -1;
     93 				}
     94 				*estr = string;
     95 			}
     96 			while (*string++);
     97 
     98 			if (pestr) {
     99 				*estr = pestr;
    100 				return 1;
    101 			} else {
    102 				*estr = oestr;
    103 				return 0;
    104 			}
    105 
    106 		case '[':
    107 			match = 0;
    108 			if ((negate_range = (*pattern == '^')) != 0)
    109 				pattern++;
    110 			while ((rangec = *pattern++) != '\0') {
    111 				if (rangec == ']')
    112 					break;
    113 				if (match)
    114 					continue;
    115 				if (rangec == '-' && *(pattern - 2) != '[' &&
    116 				    *pattern != ']') {
    117 					match =
    118 					    stringc <= (u_char)*pattern &&
    119 					    (u_char)*(pattern - 2) <= stringc;
    120 					pattern++;
    121 				} else
    122 					match = (stringc == rangec);
    123 			}
    124 			if (rangec == 0)
    125 				return -1;
    126 			if (match == negate_range)
    127 				return 0;
    128 			*estr = string;
    129 			break;
    130 		default:
    131 			if (patternc != stringc)
    132 				return 0;
    133 			*estr = string;
    134 			break;
    135 		}
    136 	}
    137 }
    138