LXR busybox/e2fsprogs/old_e2fsprogs/e2p/mntopts.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * mountopts.c --- convert between default mount options and strings
   4 *
   5 * Copyright (C) 2002  Theodore Ts'o <tytso@mit.edu>
   6 *
   7 * This file can be redistributed under the terms of the GNU Library General
   8 * Public License
   9 *
  10 */
  11
  12#include <stdio.h>
  13#include <stdlib.h>
  14#include <string.h>
  15#include <ctype.h>
  16#include <errno.h>
  17
  18#include "e2p.h"
  19
  20struct mntopt {
  21        unsigned int    mask;
  22        const char      *string;
  23};
  24
  25static const struct mntopt mntopt_list[] = {
  26        { EXT2_DEFM_DEBUG,      "debug" },
  27        { EXT2_DEFM_BSDGROUPS,  "bsdgroups" },
  28        { EXT2_DEFM_XATTR_USER, "user_xattr" },
  29        { EXT2_DEFM_ACL,        "acl" },
  30        { EXT2_DEFM_UID16,      "uid16" },
  31        { EXT3_DEFM_JMODE_DATA, "journal_data" },
  32        { EXT3_DEFM_JMODE_ORDERED, "journal_data_ordered" },
  33        { EXT3_DEFM_JMODE_WBACK, "journal_data_writeback" },
  34        { 0, 0 },
  35};
  36
  37const char *e2p_mntopt2string(unsigned int mask)
  38{
  39        const struct mntopt  *f;
  40        static char buf[20];
  41        int     fnum;
  42
  43        for (f = mntopt_list; f->string; f++) {
  44                if (mask == f->mask)
  45                        return f->string;
  46        }
  47        for (fnum = 0; mask >>= 1; fnum++);
  48        sprintf(buf, "MNTOPT_%d", fnum);
  49        return buf;
  50}
  51
  52int e2p_string2mntopt(char *string, unsigned int *mask)
  53{
  54        const struct mntopt  *f;
  55        char            *eptr;
  56        int             num;
  57
  58        for (f = mntopt_list; f->string; f++) {
  59                if (!strcasecmp(string, f->string)) {
  60                        *mask = f->mask;
  61                        return 0;
  62                }
  63        }
  64        if (strncasecmp(string, "MNTOPT_", 8))
  65                return 1;
  66
  67        if (string[8] == 0)
  68                return 1;
  69        num = strtol(string+8, &eptr, 10);
  70        if (num > 32 || num < 0)
  71                return 1;
  72        if (*eptr)
  73                return 1;
  74        *mask = 1 << num;
  75        return 0;
  76}
  77
  78static char *skip_over_blanks(char *cp)
  79{
  80        while (*cp && isspace(*cp))
  81                cp++;
  82        return cp;
  83}
  84
  85static char *skip_over_word(char *cp)
  86{
  87        while (*cp && !isspace(*cp) && *cp != ',')
  88                cp++;
  89        return cp;
  90}
  91
  92/*
  93 * Edit a mntopt set array as requested by the user.  The ok
  94 * parameter, if non-zero, allows the application to limit what
  95 * mntopts the user is allowed to set or clear using this function.
  96 */
  97int e2p_edit_mntopts(const char *str, __u32 *mntopts, __u32 ok)
  98{
  99        char    *cp, *buf, *next;
 100        int     neg;
 101        unsigned int    mask;
 102
 103        buf = xstrdup(str);
 104        cp = buf;
 105        while (cp && *cp) {
 106                neg = 0;
 107                cp = skip_over_blanks(cp);
 108                next = skip_over_word(cp);
 109                if (*next == 0)
 110                        next = 0;
 111                else
 112                        *next = 0;
 113                switch (*cp) {
 114                case '-':
 115                case '^':
 116                        neg++;
 117                case '+':
 118                        cp++;
 119                        break;
 120                }
 121                if (e2p_string2mntopt(cp, &mask))
 122                        return 1;
 123                if (ok && !(ok & mask))
 124                        return 1;
 125                if (mask & EXT3_DEFM_JMODE)
 126                        *mntopts &= ~EXT3_DEFM_JMODE;
 127                if (neg)
 128                        *mntopts &= ~mask;
 129                else
 130                        *mntopts |= mask;
 131                cp = next ? next+1 : 0;
 132        }
 133        return 0;
 134}
 135