source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/e2p/mntopts.c@ 821

/*
 * mountopts.c --- convert between default mount options and strings
 *
 * Copyright (C) 2002  Theodore Ts'o <tytso@mit.edu>
 *
 * This file can be redistributed under the terms of the GNU Library General
 * Public License
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "e2p.h"

struct mntopt {
    unsigned int    mask;
    const char  *string;
};

static const struct mntopt mntopt_list[] = {
    { EXT2_DEFM_DEBUG,  "debug" },
    { EXT2_DEFM_BSDGROUPS,  "bsdgroups" },
    { EXT2_DEFM_XATTR_USER, "user_xattr" },
    { EXT2_DEFM_ACL,    "acl" },
    { EXT2_DEFM_UID16,  "uid16" },
    { EXT3_DEFM_JMODE_DATA, "journal_data" },
    { EXT3_DEFM_JMODE_ORDERED, "journal_data_ordered" },
    { EXT3_DEFM_JMODE_WBACK, "journal_data_writeback" },
    { 0, 0 },
};

const char *e2p_mntopt2string(unsigned int mask)
{
    const struct mntopt  *f;
    static char buf[20];
    int fnum;

    for (f = mntopt_list; f->string; f++) {
        if (mask == f->mask)
            return f->string;
    }
    for (fnum = 0; mask >>= 1; fnum++);
    sprintf(buf, "MNTOPT_%d", fnum);
    return buf;
}

int e2p_string2mntopt(char *string, unsigned int *mask)
{
    const struct mntopt  *f;
    char        *eptr;
    int     num;

    for (f = mntopt_list; f->string; f++) {
        if (!strcasecmp(string, f->string)) {
            *mask = f->mask;
            return 0;
        }
    }
    if (strncasecmp(string, "MNTOPT_", 8))
        return 1;

    if (string[8] == 0)
        return 1;
    num = strtol(string+8, &eptr, 10);
    if (num > 32 || num < 0)
        return 1;
    if (*eptr)
        return 1;
    *mask = 1 << num;
    return 0;
}

static char *skip_over_blanks(char *cp)
{
    while (*cp && isspace(*cp))
        cp++;
    return cp;
}

static char *skip_over_word(char *cp)
{
    while (*cp && !isspace(*cp) && *cp != ',')
        cp++;
    return cp;
}

/*
 * Edit a mntopt set array as requested by the user.  The ok
 * parameter, if non-zero, allows the application to limit what
 * mntopts the user is allowed to set or clear using this function.
 */
int e2p_edit_mntopts(const char *str, __u32 *mntopts, __u32 ok)
{
    char    *cp, *buf, *next;
    int neg;
    unsigned int    mask;

    buf = bb_xstrdup(str);
    cp = buf;
    while (cp && *cp) {
        neg = 0;
        cp = skip_over_blanks(cp);
        next = skip_over_word(cp);
        if (*next == 0)
            next = 0;
        else
            *next = 0;
        switch (*cp) {
        case '-':
        case '^':
            neg++;
        case '+':
            cp++;
            break;
        }
        if (e2p_string2mntopt(cp, &mask))
            return 1;
        if (ok && !(ok & mask))
            return 1;
        if (mask & EXT3_DEFM_JMODE)
            *mntopts &= ~EXT3_DEFM_JMODE;
        if (neg)
            *mntopts &= ~mask;
        else
            *mntopts |= mask;
        cp = next ? next+1 : 0;
    }
    return 0;
}