/*      $OpenBSD: getmntopts.c,v 1.13 2019/06/28 13:32:44 deraadt Exp $ */
/*      $NetBSD: getmntopts.c,v 1.3 1995/03/18 14:56:58 cgd Exp $       */

/*-
 * Copyright (c) 1994
 *      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/types.h>
#include <sys/mount.h>

#include <err.h>
#include <errno.h>
#include <fstab.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#include "mntopts.h"

int
getmntopts(const char *optionp, const struct mntopt *m0, int *flagp)
{
        char *p, *q;
        union mntval val;
        int ret = 0;

        p = q = strdup(optionp);
        if (p == NULL)
                err(1, NULL);
        while (p != NULL) {
                ret |= getmntopt(&p, &val, m0, flagp);
        }
        free(q);
        return (ret);
}

int
getmntopt(char **optionp, union mntval *valuep, const struct mntopt *m0,
    int *flagp)
{
        const struct mntopt *m;
        char *opt, *value, *endp;
        long l;
        int inverse, negative, needval, ret = 0;

        /* Pull out the next option. */
        do {
                if (*optionp == NULL)
                        return (0);
                opt = strsep(optionp, ",");
        } while (opt == NULL || *opt == '\0');

        /* Check for "no" prefix. */
        if (opt[0] == 'n' && opt[1] == 'o') {
                negative = 1;
                opt += 2;
        } else
                negative = 0;

        /* Stash the value for options with assignments in them. */
        if ((value = strchr(opt, '=')) != NULL)
                *value++ = '\0';

        /* Scan option table. */
        for (m = m0; m->m_option != NULL; ++m)
                if (strcasecmp(opt, m->m_option) == 0)
                        break;

        /* Save flag, or fail if option is not recognised. */
        if (m->m_option) {
                needval = (m->m_oflags & (MFLAG_INTVAL|MFLAG_STRVAL)) != 0;
                if (needval != (value != NULL) && !(m->m_oflags & MFLAG_OPT))
                        errx(1, "-o %s: option %s a value", opt,
                            needval ? "needs" : "does not need");
                inverse = (m->m_oflags & MFLAG_INVERSE) ? 1 : 0;
                if (m->m_oflags & MFLAG_SET) {
                        if (negative == inverse)
                                *flagp |= m->m_flag;
                        else
                                *flagp &= ~m->m_flag;
                }
                else if (negative == inverse)
                        ret = m->m_flag;
        } else
                errx(1, "-o %s: option not supported", opt);

        /* Store the value for options with assignments in them. */
        if (value != NULL) {
                if (m->m_oflags & MFLAG_INTVAL) {
                        errno = 0;
                        l = strtol(value, &endp, 10);
                        if (endp == value || l == -1 || l > INT_MAX ||
                            (l == LONG_MAX && errno == ERANGE))
                                errx(1, "%s: illegal value '%s'",
                                    opt, value);
                        valuep->ival = (int)l;
                } else
                        valuep->strval = value;
        } else
                memset(valuep, 0, sizeof(*valuep));
        return (ret);
}