/*
 * Copyright (c) 1989, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Guido van Rossum.
 *
 * 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.
 */

/*
 * Copyright 2013 Garrett D'Amore <garrett@damore.org>
 * Copyright 2017 Nexenta Systems, Inc.
 */

/*
 * Function fnmatch() as specified in POSIX 1003.2-1992, section B.6.
 * Compares a filename or pathname to a pattern.
 */

/*
 * Some notes on multibyte character support:
 * 1. Patterns with illegal byte sequences match nothing.
 * 2. Illegal byte sequences in the "string" argument are handled by treating
 *    them as single-byte characters with a value of the first byte of the
 *    sequence cast to wchar_t.
 * 3. Multibyte conversion state objects (mbstate_t) are passed around and
 *    used for most, but not all, conversions. Further work will be required
 *    to support state-dependent encodings.
 */

#include "lint.h"
#include <fnmatch.h>
#include <limits.h>
#include <string.h>
#include <wchar.h>
#include <xlocale.h>
#include <wctype.h>
#include "localeimpl.h"
#include "collate.h"

#define EOS     '\0'

#define RANGE_MATCH     1
#define RANGE_NOMATCH   0
#define RANGE_ERROR     (-1)

static int rangematch(const char *, wchar_t, int, char **, mbstate_t *,
    locale_t);
static int fnmatch1(const char *, const char *, const char *, int, mbstate_t,
    mbstate_t, locale_t);

int
fnmatch(const char *pattern, const char *string, int flags)
{
        locale_t loc = uselocale(NULL);
        static const mbstate_t initial = { 0 };

        return (fnmatch1(pattern, string, string, flags, initial, initial,
            loc));
}

static int
fnmatch1(const char *pattern, const char *string, const char *stringstart,
    int flags, mbstate_t patmbs, mbstate_t strmbs, locale_t loc)
{
        const char *bt_pattern, *bt_string;
        mbstate_t bt_patmbs, bt_strmbs;
        char *newp;
        char c;
        wchar_t pc, sc;
        size_t pclen, sclen;

        bt_pattern = bt_string = NULL;
        for (;;) {
                pclen = mbrtowc_l(&pc, pattern, MB_LEN_MAX, &patmbs, loc);
                if (pclen == (size_t)-1 || pclen == (size_t)-2)
                        return (FNM_NOMATCH);
                pattern += pclen;
                sclen = mbrtowc_l(&sc, string, MB_LEN_MAX, &strmbs, loc);
                if (sclen == (size_t)-1 || sclen == (size_t)-2) {
                        sc = (unsigned char)*string;
                        sclen = 1;
                        (void) memset(&strmbs, 0, sizeof (strmbs));
                }
                switch (pc) {
                case EOS:
                        if ((flags & FNM_LEADING_DIR) && sc == '/')
                                return (0);
                        if (sc == EOS)
                                return (0);
                        goto backtrack;
                case '?':
                        if (sc == EOS)
                                return (FNM_NOMATCH);
                        if (sc == '/' && (flags & FNM_PATHNAME))
                                goto backtrack;
                        if (sc == '.' && (flags & FNM_PERIOD) &&
                            (string == stringstart ||
                            ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
                                goto backtrack;
                        string += sclen;
                        break;
                case '*':
                        c = *pattern;
                        /* Collapse multiple stars. */
                        while (c == '*')
                                c = *++pattern;

                        if (sc == '.' && (flags & FNM_PERIOD) &&
                            (string == stringstart ||
                            ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
                                goto backtrack;

                        /* Optimize for pattern with * at end or before /. */
                        if (c == EOS)
                                if (flags & FNM_PATHNAME)
                                        return ((flags & FNM_LEADING_DIR) ||
                                            strchr(string, '/') == NULL ?
                                            0 : FNM_NOMATCH);
                                else
                                        return (0);
                        else if (c == '/' && flags & FNM_PATHNAME) {
                                if ((string = strchr(string, '/')) == NULL)
                                        return (FNM_NOMATCH);
                                break;
                        }

                        /*
                         * First try the shortest match for the '*' that
                         * could work. We can forget any earlier '*' since
                         * there is no way having it match more characters
                         * can help us, given that we are already here.
                         */
                        bt_pattern = pattern, bt_patmbs = patmbs;
                        bt_string = string, bt_strmbs = strmbs;
                        break;
                case '[':
                        if (sc == EOS)
                                return (FNM_NOMATCH);
                        if (sc == '/' && (flags & FNM_PATHNAME))
                                goto backtrack;
                        if (sc == '.' && (flags & FNM_PERIOD) &&
                            (string == stringstart ||
                            ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
                                goto backtrack;

                        switch (rangematch(pattern, sc, flags, &newp,
                            &patmbs, loc)) {
                        case RANGE_ERROR:
                                goto norm;
                        case RANGE_MATCH:
                                pattern = newp;
                                break;
                        case RANGE_NOMATCH:
                                goto backtrack;
                        }
                        string += sclen;
                        break;
                case '\\':
                        if (!(flags & FNM_NOESCAPE)) {
                                pclen = mbrtowc_l(&pc, pattern, MB_LEN_MAX,
                                    &patmbs, loc);
                                if (pclen == 0 || pclen == (size_t)-1 ||
                                    pclen == (size_t)-2)
                                        return (FNM_NOMATCH);
                                pattern += pclen;
                        }
                        /* FALLTHROUGH */
                default:
                norm:
                        string += sclen;
                        if (pc == sc)
                                break;
                        else if ((flags & FNM_CASEFOLD) &&
                            (towlower_l(pc, loc) == towlower_l(sc, loc)))
                                break;
                        else {
                backtrack:
                                /*
                                 * If we have a mismatch (other than hitting
                                 * the end of the string), go back to the last
                                 * '*' seen and have it match one additional
                                 * character.
                                 */
                                if (bt_pattern == NULL)
                                        return (FNM_NOMATCH);
                                sclen = mbrtowc_l(&sc, bt_string, MB_LEN_MAX,
                                    &bt_strmbs, loc);
                                if (sclen == (size_t)-1 ||
                                    sclen == (size_t)-2) {
                                        sc = (unsigned char)*bt_string;
                                        sclen = 1;
                                        (void) memset(&bt_strmbs, 0,
                                            sizeof (bt_strmbs));
                                }
                                if (sc == EOS)
                                        return (FNM_NOMATCH);
                                if (sc == '/' && flags & FNM_PATHNAME)
                                        return (FNM_NOMATCH);
                                bt_string += sclen;
                                pattern = bt_pattern, patmbs = bt_patmbs;
                                string = bt_string, strmbs = bt_strmbs;
                        }
                        break;
                }
        }
        /* NOTREACHED */
}

static int
rangematch(const char *pattern, wchar_t test, int flags, char **newp,
    mbstate_t *patmbs, locale_t loc)
{
        int negate, ok;
        wchar_t c, c2;
        size_t pclen;
        const char *origpat;

        /*
         * A bracket expression starting with an unquoted circumflex
         * character produces unspecified results (IEEE 1003.2-1992,
         * 3.13.2).  This implementation treats it like '!', for
         * consistency with the regular expression syntax.
         * J.T. Conklin (conklin@ngai.kaleida.com)
         */
        if ((negate = (*pattern == '!' || *pattern == '^')) != 0)
                ++pattern;

        if (flags & FNM_CASEFOLD)
                test = towlower_l(test, loc);

        /*
         * A right bracket shall lose its special meaning and represent
         * itself in a bracket expression if it occurs first in the list.
         * -- POSIX.2 2.8.3.2
         */
        ok = 0;
        origpat = pattern;
        for (;;) {
                if (*pattern == ']' && pattern > origpat) {
                        pattern++;
                        break;
                } else if (*pattern == '\0') {
                        return (RANGE_ERROR);
                } else if (*pattern == '/' && (flags & FNM_PATHNAME)) {
                        return (RANGE_NOMATCH);
                } else if (*pattern == '\\' && !(flags & FNM_NOESCAPE))
                        pattern++;
                pclen = mbrtowc_l(&c, pattern, MB_LEN_MAX, patmbs, loc);
                if (pclen == (size_t)-1 || pclen == (size_t)-2)
                        return (RANGE_NOMATCH);
                pattern += pclen;

                if (flags & FNM_CASEFOLD)
                        c = towlower_l(c, loc);

                if (*pattern == '-' && *(pattern + 1) != EOS &&
                    *(pattern + 1) != ']') {
                        if (*++pattern == '\\' && !(flags & FNM_NOESCAPE))
                                if (*pattern != EOS)
                                        pattern++;
                        pclen = mbrtowc_l(&c2, pattern, MB_LEN_MAX, patmbs,
                            loc);
                        if (pclen == (size_t)-1 || pclen == (size_t)-2)
                                return (RANGE_NOMATCH);
                        pattern += pclen;
                        if (c2 == EOS)
                                return (RANGE_ERROR);

                        if (flags & FNM_CASEFOLD)
                                c2 = towlower_l(c2, loc);

                        if (loc->collate->lc_is_posix ?
                            c <= test && test <= c2 :
                            _collate_range_cmp(c, test, loc) <= 0 &&
                            _collate_range_cmp(test, c2, loc) <= 0)
                                ok = 1;
                } else if (c == test)
                        ok = 1;
        }

        *newp = (char *)pattern;
        return (ok == negate ? RANGE_NOMATCH : RANGE_MATCH);
}