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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* This file is part of libmount from util-linux project.
*
* Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
*
* libmount is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*/
/**
* SECTION: optmap
* @title: Option maps
* @short_description: description for mount options
*
* The mount(2) linux syscall uses two arguments for mount options:
*
* @mountflags: (see MS_* macros in linux/fs.h)
*
* @mountdata: (usually a comma separated string of options)
*
* The libmount uses options-map(s) to describe mount options.
*
* The option description (map entry) includes:
*
* @name: and argument name
*
* @id: (in the map unique identifier or a mountflags, e.g MS_RDONLY)
*
* @mask: (MNT_INVERT, MNT_NOMTAB)
*
* The option argument value is defined by:
*
* "=" -- required argument, e.g "comment="
*
* "[=]" -- optional argument, e.g. "loop[=]"
*
* Example:
*
* <informalexample>
* <programlisting>
* #define MY_MS_FOO (1 << 1)
* #define MY_MS_BAR (1 << 2)
*
* libmnt_optmap myoptions[] = {
* { "foo", MY_MS_FOO },
* { "nofoo", MY_MS_FOO | MNT_INVERT },
* { "bar=", MY_MS_BAR },
* { NULL }
* };
* </programlisting>
* </informalexample>
*
* The libmount defines two basic built-in options maps:
*
* @MNT_LINUX_MAP: fs-independent kernel mount options (usually MS_* flags)
*
* @MNT_USERSPACE_MAP: userspace specific mount options (e.g. "user", "loop")
*
* For more details about option map struct see "struct mnt_optmap" in
* mount/mount.h.
*/
#include "mountP.h"
#include "strutils.h"
/*
* fs-independent mount flags (built-in MNT_LINUX_MAP)
*/
static const struct libmnt_optmap linux_flags_map[] =
{
{ "ro", MS_RDONLY }, /* read-only */
{ "rw", MS_RDONLY, MNT_INVERT }, /* read-write */
{ "exec", MS_NOEXEC, MNT_INVERT }, /* permit execution of binaries */
{ "noexec", MS_NOEXEC }, /* don't execute binaries */
{ "suid", MS_NOSUID, MNT_INVERT }, /* honor suid executables */
{ "nosuid", MS_NOSUID }, /* don't honor suid executables */
{ "dev", MS_NODEV, MNT_INVERT }, /* interpret device files */
{ "nodev", MS_NODEV }, /* don't interpret devices */
{ "sync", MS_SYNCHRONOUS }, /* synchronous I/O */
{ "async", MS_SYNCHRONOUS, MNT_INVERT },/* asynchronous I/O */
{ "dirsync", MS_DIRSYNC }, /* synchronous directory modifications */
{ "remount", MS_REMOUNT, MNT_NOMTAB }, /* alter flags of mounted FS */
{ "bind", MS_BIND }, /* Remount part of the tree elsewhere */
{ "rbind", MS_BIND | MS_REC }, /* Idem, plus mounted subtrees */
#ifdef MS_NOSUB
{ "sub", MS_NOSUB, MNT_INVERT }, /* allow submounts */
{ "nosub", MS_NOSUB }, /* don't allow submounts */
#endif
#ifdef MS_SILENT
{ "silent", MS_SILENT }, /* be quiet */
{ "loud", MS_SILENT, MNT_INVERT }, /* print out messages. */
#endif
#ifdef MS_MANDLOCK
{ "mand", MS_MANDLOCK }, /* Allow mandatory locks on this FS */
{ "nomand", MS_MANDLOCK, MNT_INVERT }, /* Forbid mandatory locks on this FS */
#endif
#ifdef MS_NOATIME
{ "atime", MS_NOATIME, MNT_INVERT }, /* Update access time */
{ "noatime", MS_NOATIME }, /* Do not update access time */
#endif
#ifdef MS_I_VERSION
{ "iversion", MS_I_VERSION }, /* Update inode I_version time */
{ "noiversion", MS_I_VERSION, MNT_INVERT},/* Don't update inode I_version time */
#endif
#ifdef MS_NODIRATIME
{ "diratime", MS_NODIRATIME, MNT_INVERT }, /* Update dir access times */
{ "nodiratime", MS_NODIRATIME }, /* Do not update dir access times */
#endif
#ifdef MS_RELATIME
{ "relatime", MS_RELATIME }, /* Update access times relative to mtime/ctime */
{ "norelatime", MS_RELATIME, MNT_INVERT }, /* Update access time without regard to mtime/ctime */
#endif
#ifdef MS_STRICTATIME
{ "strictatime", MS_STRICTATIME }, /* Strict atime semantics */
{ "nostrictatime", MS_STRICTATIME, MNT_INVERT }, /* kernel default atime */
#endif
#ifdef MS_LAZYTIME
{ "lazytime", MS_LAZYTIME }, /* Update {a,m,c}time on the in-memory inode only */
{ "nolazytime", MS_LAZYTIME, MNT_INVERT },
#endif
#ifdef MS_PROPAGATION
{ "unbindable", MS_UNBINDABLE, MNT_NOHLPS | MNT_NOMTAB }, /* Unbindable */
{ "runbindable", MS_UNBINDABLE | MS_REC, MNT_NOHLPS | MNT_NOMTAB },
{ "private", MS_PRIVATE, MNT_NOHLPS | MNT_NOMTAB }, /* Private */
{ "rprivate", MS_PRIVATE | MS_REC, MNT_NOHLPS | MNT_NOMTAB },
{ "slave", MS_SLAVE, MNT_NOHLPS | MNT_NOMTAB }, /* Slave */
{ "rslave", MS_SLAVE | MS_REC, MNT_NOHLPS | MNT_NOMTAB },
{ "shared", MS_SHARED, MNT_NOHLPS | MNT_NOMTAB }, /* Shared */
{ "rshared", MS_SHARED | MS_REC, MNT_NOHLPS | MNT_NOMTAB },
#endif
#ifdef MS_NOSYMFOLLOW
{ "symfollow", MS_NOSYMFOLLOW, MNT_INVERT }, /* Don't follow symlinks */
{ "nosymfollow", MS_NOSYMFOLLOW },
#endif
{ NULL, 0, 0 }
};
/*
* userspace mount option (built-in MNT_USERSPACE_MAP)
*/
static const struct libmnt_optmap userspace_opts_map[] =
{
{ "defaults", 0, 0 }, /* default options */
{ "auto", MNT_MS_NOAUTO, MNT_NOHLPS | MNT_INVERT | MNT_NOMTAB }, /* Can be mounted using -a */
{ "noauto", MNT_MS_NOAUTO, MNT_NOHLPS | MNT_NOMTAB }, /* Can only be mounted explicitly */
{ "user[=]", MNT_MS_USER }, /* Allow ordinary user to mount (mtab) */
{ "nouser", MNT_MS_USER, MNT_INVERT | MNT_NOMTAB }, /* Forbid ordinary user to mount */
{ "users", MNT_MS_USERS, MNT_NOMTAB }, /* Allow ordinary users to mount */
{ "nousers", MNT_MS_USERS, MNT_INVERT | MNT_NOMTAB }, /* Forbid ordinary users to mount */
{ "owner", MNT_MS_OWNER, MNT_NOMTAB }, /* Let the owner of the device mount */
{ "noowner", MNT_MS_OWNER, MNT_INVERT | MNT_NOMTAB }, /* Device owner has no special privs */
{ "group", MNT_MS_GROUP, MNT_NOMTAB }, /* Let the group of the device mount */
{ "nogroup", MNT_MS_GROUP, MNT_INVERT | MNT_NOMTAB }, /* Device group has no special privs */
/*
* Note that traditional init scripts assume the _netdev option in /etc/mtab to
* umount network block devices on shutdown.
*/
{ "_netdev", MNT_MS_NETDEV }, /* Device requires network */
{ "comment=", MNT_MS_COMMENT, MNT_NOHLPS | MNT_NOMTAB },/* fstab comment only */
{ "x-", MNT_MS_XCOMMENT, MNT_NOHLPS | MNT_PREFIX }, /* persistent comments (utab) */
{ "X-", MNT_MS_XFSTABCOMM, MNT_NOHLPS | MNT_NOMTAB | MNT_PREFIX }, /* fstab only comments */
{ "loop[=]", MNT_MS_LOOP, MNT_NOHLPS }, /* use the loop device */
{ "offset=", MNT_MS_OFFSET, MNT_NOHLPS | MNT_NOMTAB }, /* loop device offset */
{ "sizelimit=", MNT_MS_SIZELIMIT, MNT_NOHLPS | MNT_NOMTAB }, /* loop device size limit */
{ "encryption=", MNT_MS_ENCRYPTION, MNT_NOHLPS | MNT_NOMTAB }, /* loop device encryption */
{ "nofail", MNT_MS_NOFAIL, MNT_NOMTAB }, /* Do not fail if ENOENT on dev */
{ "uhelper=", MNT_MS_UHELPER }, /* /sbin/umount.<helper> */
{ "helper=", MNT_MS_HELPER }, /* /sbin/mount.<helper> */
{ "verity.hashdevice=", MNT_MS_HASH_DEVICE, MNT_NOHLPS | MNT_NOMTAB }, /* mount a verity device */
{ "verity.roothash=", MNT_MS_ROOT_HASH, MNT_NOHLPS | MNT_NOMTAB }, /* verity device root hash */
{ "verity.hashoffset=", MNT_MS_HASH_OFFSET, MNT_NOHLPS | MNT_NOMTAB }, /* verity device hash offset */
{ "verity.roothashfile=", MNT_MS_ROOT_HASH_FILE, MNT_NOHLPS | MNT_NOMTAB },/* verity device root hash (read from file) */
{ "verity.fecdevice=", MNT_MS_FEC_DEVICE, MNT_NOHLPS | MNT_NOMTAB }, /* verity FEC device */
{ "verity.fecoffset=", MNT_MS_FEC_OFFSET, MNT_NOHLPS | MNT_NOMTAB }, /* verity FEC area offset */
{ "verity.fecroots=", MNT_MS_FEC_ROOTS, MNT_NOHLPS | MNT_NOMTAB }, /* verity FEC roots */
{ "verity.roothashsig=", MNT_MS_ROOT_HASH_SIG, MNT_NOHLPS | MNT_NOMTAB }, /* verity device root hash signature file */
{ "verity.oncorruption=", MNT_MS_VERITY_ON_CORRUPTION, MNT_NOHLPS | MNT_NOMTAB }, /* verity: action the kernel takes on corruption */
{ NULL, 0, 0 }
};
/**
* mnt_get_builtin_map:
* @id: map id -- MNT_LINUX_MAP or MNT_USERSPACE_MAP
*
* MNT_LINUX_MAP - Linux kernel fs-independent mount options
* (usually MS_* flags, see linux/fs.h)
*
* MNT_USERSPACE_MAP - userspace mount(8) specific mount options
* (e.g user=, _netdev, ...)
*
* Returns: static built-in libmount map.
*/
const struct libmnt_optmap *mnt_get_builtin_optmap(int id)
{
assert(id);
if (id == MNT_LINUX_MAP)
return linux_flags_map;
if (id == MNT_USERSPACE_MAP)
return userspace_opts_map;
return NULL;
}
/*
* Looks up the @name in @maps and returns a map and in @mapent
* returns the map entry
*/
const struct libmnt_optmap *mnt_optmap_get_entry(
struct libmnt_optmap const **maps,
int nmaps,
const char *name,
size_t namelen,
const struct libmnt_optmap **mapent)
{
int i;
assert(maps);
assert(nmaps);
assert(name);
assert(namelen);
if (mapent)
*mapent = NULL;
for (i = 0; i < nmaps; i++) {
const struct libmnt_optmap *map = maps[i];
const struct libmnt_optmap *ent;
const char *p;
for (ent = map; ent && ent->name; ent++) {
if (ent->mask & MNT_PREFIX) {
if (startswith(name, ent->name)) {
if (mapent)
*mapent = ent;
return map;
}
continue;
}
if (strncmp(ent->name, name, namelen) != 0)
continue;
p = ent->name + namelen;
if (*p == '\0' || *p == '=' || *p == '[') {
if (mapent)
*mapent = ent;
return map;
}
}
}
return NULL;
}
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