blob: ff2e5de9a8c21d0332d67b3a099bdd704af1d4e2 [file] [log] [blame]
/*
* mountopts.c --- convert between default mount options and strings
*
* Copyright (C) 2002 Theodore Ts'o <tytso@mit.edu>
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include "config.h"
#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 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" },
{ EXT4_DEFM_NOBARRIER, "nobarrier" },
{ EXT4_DEFM_BLOCK_VALIDITY, "block_validity" },
{ EXT4_DEFM_DISCARD, "discard"},
{ EXT4_DEFM_NODELALLOC, "nodelalloc"},
{ 0, 0 },
};
const char *e2p_mntopt2string(unsigned int mask)
{
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)
{
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_", 7))
return 1;
if (string[8] == 0)
return 1;
num = strtol(string+8, &eptr, 10);
if (num > 31 || 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;
int rc = 0;
buf = malloc(strlen(str)+1);
if (!buf)
return 1;
strcpy(buf, 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++;
/* fallthrough */
case '+':
cp++;
break;
}
if (e2p_string2mntopt(cp, &mask)) {
rc = 1;
break;
}
if (ok && !(ok & mask)) {
rc = 1;
break;
}
if (mask & EXT3_DEFM_JMODE)
*mntopts &= ~EXT3_DEFM_JMODE;
if (neg)
*mntopts &= ~mask;
else
*mntopts |= mask;
cp = next ? next+1 : 0;
}
free(buf);
return rc;
}