/*      $NetBSD: pmatch.c,v 1.9 2024/10/09 23:16:03 gutteridge Exp $    */

/*-
 * Copyright (c) 1980, 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>

/* So we can build this in userland for the tests in strlist.c */
#if defined(_KERNEL) || defined(_STANDALONE)
#include <lib/libkern/libkern.h>
#else
int pmatch(const char *, const char *, const char **);
#endif

/*
 * pmatch():
 *      Return 2 on exact match.
 *      Return 1 on substring match.
 *      Return 0 on no match.
 *      Return -1 on error.
 * *estr will point to the end of the longest exact or substring match.
 */
int
pmatch(const char *string, const char *pattern, const char **estr)
{
        u_char stringc, patternc, rangec;
        int match, negate_range;
        const char *oestr, *pestr, *testr = NULL;

        if (estr == NULL)
                estr = &testr;

        for (;; ++string) {
                stringc = *string;
                switch (patternc = *pattern++) {
                case 0:
                        *estr = string;
                        return stringc == '\0' ? 2 : 1;
                case '?':
                        if (stringc == '\0')
                                return 0;
                        *estr = string;
                        break;
                case '*':
                        if (!*pattern) {
                                while (*string)
                                        string++;
                                *estr = string;
                                return 2;
                        }
                        oestr = *estr;
                        pestr = NULL;

                        do {
                                switch (pmatch(string, pattern, estr)) {
                                case -1:
                                        return -1;
                                case 0:
                                        break;
                                case 1:
                                        pestr = *estr;
                                        break;
                                case 2:
                                        return 2;
                                default:
                                        return -1;
                                }
                                *estr = string;
                        }
                        while (*string++);

                        if (pestr) {
                                *estr = pestr;
                                return 1;
                        } else {
                                *estr = oestr;
                                return 0;
                        }

                case '[':
                        match = 0;
                        if ((negate_range = (*pattern == '^')) != 0)
                                pattern++;
                        while ((rangec = *pattern++) != '\0') {
                                if (rangec == ']')
                                        break;
                                if (match)
                                        continue;
                                if (rangec == '-' && *(pattern - 2) != '[' &&
                                    *pattern != ']') {
                                        match =
                                            stringc <= (u_char)*pattern &&
                                            (u_char)*(pattern - 2) <= stringc;
                                        pattern++;
                                } else
                                        match = (stringc == rangec);
                        }
                        if (rangec == 0)
                                return -1;
                        if (match == negate_range)
                                return 0;
                        *estr = string;
                        break;
                default:
                        if (patternc != stringc)
                                return 0;
                        *estr = string;
                        break;
                }
        }
}