/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2015 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2014, 2020 by Delphix. All rights reserved.
* Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
* Copyright 2017 RackTop Systems.
* Copyright (c) 2018 Datto Inc.
* Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
*/
#include <dirent.h>
#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <libintl.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <zone.h>
#include <sys/mntent.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <sys/dsl_crypt.h>
#include <libzfs.h>
#include "libzfs_impl.h"
#include <thread_pool.h>
#define ZS_COMMENT 0x00000000 /* comment */
#define ZS_ZFSUTIL 0x00000001 /* caller is zfs(8) */
typedef struct option_map {
const char *name;
unsigned long mntmask;
unsigned long zfsmask;
} option_map_t;
static const option_map_t option_map[] = {
/* Canonicalized filesystem independent options from mount(8) */
{ MNTOPT_NOAUTO, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_DEFAULTS, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_NODEVICES, MS_NODEV, ZS_COMMENT },
{ MNTOPT_DEVICES, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_DIRSYNC, MS_DIRSYNC, ZS_COMMENT },
{ MNTOPT_NOEXEC, MS_NOEXEC, ZS_COMMENT },
{ MNTOPT_EXEC, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_GROUP, MS_GROUP, ZS_COMMENT },
{ MNTOPT_NETDEV, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_NOFAIL, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_NOSUID, MS_NOSUID, ZS_COMMENT },
{ MNTOPT_SUID, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_OWNER, MS_OWNER, ZS_COMMENT },
{ MNTOPT_REMOUNT, MS_REMOUNT, ZS_COMMENT },
{ MNTOPT_RO, MS_RDONLY, ZS_COMMENT },
{ MNTOPT_RW, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_SYNC, MS_SYNCHRONOUS, ZS_COMMENT },
{ MNTOPT_USER, MS_USERS, ZS_COMMENT },
{ MNTOPT_USERS, MS_USERS, ZS_COMMENT },
/* acl flags passed with util-linux-2.24 mount command */
{ MNTOPT_ACL, MS_POSIXACL, ZS_COMMENT },
{ MNTOPT_NOACL, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_POSIXACL, MS_POSIXACL, ZS_COMMENT },
#ifdef MS_NOATIME
{ MNTOPT_NOATIME, MS_NOATIME, ZS_COMMENT },
{ MNTOPT_ATIME, MS_COMMENT, ZS_COMMENT },
#endif
#ifdef MS_NODIRATIME
{ MNTOPT_NODIRATIME, MS_NODIRATIME, ZS_COMMENT },
{ MNTOPT_DIRATIME, MS_COMMENT, ZS_COMMENT },
#endif
#ifdef MS_RELATIME
{ MNTOPT_RELATIME, MS_RELATIME, ZS_COMMENT },
{ MNTOPT_NORELATIME, MS_COMMENT, ZS_COMMENT },
#endif
#ifdef MS_STRICTATIME
{ MNTOPT_STRICTATIME, MS_STRICTATIME, ZS_COMMENT },
{ MNTOPT_NOSTRICTATIME, MS_COMMENT, ZS_COMMENT },
#endif
#ifdef MS_LAZYTIME
{ MNTOPT_LAZYTIME, MS_LAZYTIME, ZS_COMMENT },
#endif
{ MNTOPT_CONTEXT, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_FSCONTEXT, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_DEFCONTEXT, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_ROOTCONTEXT, MS_COMMENT, ZS_COMMENT },
#ifdef MS_I_VERSION
{ MNTOPT_IVERSION, MS_I_VERSION, ZS_COMMENT },
#endif
#ifdef MS_MANDLOCK
{ MNTOPT_NBMAND, MS_MANDLOCK, ZS_COMMENT },
{ MNTOPT_NONBMAND, MS_COMMENT, ZS_COMMENT },
#endif
/* Valid options not found in mount(8) */
{ MNTOPT_BIND, MS_BIND, ZS_COMMENT },
#ifdef MS_REC
{ MNTOPT_RBIND, MS_BIND|MS_REC, ZS_COMMENT },
#endif
{ MNTOPT_COMMENT, MS_COMMENT, ZS_COMMENT },
#ifdef MS_NOSUB
{ MNTOPT_NOSUB, MS_NOSUB, ZS_COMMENT },
#endif
#ifdef MS_SILENT
{ MNTOPT_QUIET, MS_SILENT, ZS_COMMENT },
#endif
/* Custom zfs options */
{ MNTOPT_XATTR, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_NOXATTR, MS_COMMENT, ZS_COMMENT },
{ MNTOPT_ZFSUTIL, MS_COMMENT, ZS_ZFSUTIL },
{ NULL, 0, 0 } };
/*
* Break the mount option in to a name/value pair. The name is
* validated against the option map and mount flags set accordingly.
*/
static int
parse_option(char *mntopt, unsigned long *mntflags,
unsigned long *zfsflags, int sloppy)
{
const option_map_t *opt;
char *ptr, *name, *value = NULL;
int error = 0;
name = strdup(mntopt);
if (name == NULL)
return (ENOMEM);
for (ptr = name; ptr && *ptr; ptr++) {
if (*ptr == '=') {
*ptr = '\0';
value = ptr+1;
VERIFY3P(value, !=, NULL);
break;
}
}
for (opt = option_map; opt->name != NULL; opt++) {
if (strncmp(name, opt->name, strlen(name)) == 0) {
*mntflags |= opt->mntmask;
*zfsflags |= opt->zfsmask;
error = 0;
goto out;
}
}
if (!sloppy)
error = ENOENT;
out:
/* If required further process on the value may be done here */
free(name);
return (error);
}
/*
* Translate the mount option string in to MS_* mount flags for the
* kernel vfs. When sloppy is non-zero unknown options will be ignored
* otherwise they are considered fatal are copied in to badopt.
*/
int
zfs_parse_mount_options(char *mntopts, unsigned long *mntflags,
unsigned long *zfsflags, int sloppy, char *badopt, char *mtabopt)
{
int error = 0, quote = 0, flag = 0, count = 0;
char *ptr, *opt, *opts;
opts = strdup(mntopts);
if (opts == NULL)
return (ENOMEM);
*mntflags = 0;
opt = NULL;
/*
* Scan through all mount options which must be comma delimited.
* We must be careful to notice regions which are double quoted
* and skip commas in these regions. Each option is then checked
* to determine if it is a known option.
*/
for (ptr = opts; ptr && !flag; ptr++) {
if (opt == NULL)
opt = ptr;
if (*ptr == '"')
quote = !quote;
if (quote)
continue;
if (*ptr == '\0')
flag = 1;
if ((*ptr == ',') || (*ptr == '\0')) {
*ptr = '\0';
error = parse_option(opt, mntflags, zfsflags, sloppy);
if (error) {
strcpy(badopt, opt);
goto out;
}
if (!(*mntflags & MS_REMOUNT) &&
!(*zfsflags & ZS_ZFSUTIL) &&
mtabopt != NULL) {
if (count > 0)
strlcat(mtabopt, ",", MNT_LINE_MAX);
strlcat(mtabopt, opt, MNT_LINE_MAX);
count++;
}
opt = NULL;
}
}
out:
free(opts);
return (error);
}
static void
append_mntopt(const char *name, const char *val, char *mntopts,
char *mtabopt, boolean_t quote)
{
char tmp[MNT_LINE_MAX];
snprintf(tmp, MNT_LINE_MAX, quote ? ",%s=\"%s\"" : ",%s=%s", name, val);
if (mntopts)
strlcat(mntopts, tmp, MNT_LINE_MAX);
if (mtabopt)
strlcat(mtabopt, tmp, MNT_LINE_MAX);
}
static void
zfs_selinux_setcontext(zfs_handle_t *zhp, zfs_prop_t zpt, const char *name,
char *mntopts, char *mtabopt)
{
char context[ZFS_MAXPROPLEN];
if (zfs_prop_get(zhp, zpt, context, sizeof (context),
NULL, NULL, 0, B_FALSE) == 0) {
if (strcmp(context, "none") != 0)
append_mntopt(name, context, mntopts, mtabopt, B_TRUE);
}
}
void
zfs_adjust_mount_options(zfs_handle_t *zhp, const char *mntpoint,
char *mntopts, char *mtabopt)
{
char prop[ZFS_MAXPROPLEN];
/*
* Checks to see if the ZFS_PROP_SELINUX_CONTEXT exists
* if it does, create a tmp variable in case it's needed
* checks to see if the selinux context is set to the default
* if it is, allow the setting of the other context properties
* this is needed because the 'context' property overrides others
* if it is not the default, set the 'context' property
*/
if (zfs_prop_get(zhp, ZFS_PROP_SELINUX_CONTEXT, prop, sizeof (prop),
NULL, NULL, 0, B_FALSE) == 0) {
if (strcmp(prop, "none") == 0) {
zfs_selinux_setcontext(zhp, ZFS_PROP_SELINUX_FSCONTEXT,
MNTOPT_FSCONTEXT, mntopts, mtabopt);
zfs_selinux_setcontext(zhp, ZFS_PROP_SELINUX_DEFCONTEXT,
MNTOPT_DEFCONTEXT, mntopts, mtabopt);
zfs_selinux_setcontext(zhp,
ZFS_PROP_SELINUX_ROOTCONTEXT, MNTOPT_ROOTCONTEXT,
mntopts, mtabopt);
} else {
append_mntopt(MNTOPT_CONTEXT, prop,
mntopts, mtabopt, B_TRUE);
}
}
/* A hint used to determine an auto-mounted snapshot mount point */
append_mntopt(MNTOPT_MNTPOINT, mntpoint, mntopts, NULL, B_FALSE);
}
/*
* By default the filesystem by preparing the mount options (i.e. parsing
* some flags from the "opts" parameter into the "flags" parameter) and then
* directly calling the system call mount(2). We don't need the mount utility
* or update /etc/mtab, because this is a symlink on all modern systems.
*
* If the environment variable ZFS_MOUNT_HELPER is set, we fall back to the
* previous behavior:
* The filesystem is mounted by invoking the system mount utility rather
* than by the system call mount(2). This ensures that the /etc/mtab
* file is correctly locked for the update. Performing our own locking
* and /etc/mtab update requires making an unsafe assumption about how
* the mount utility performs its locking. Unfortunately, this also means
* in the case of a mount failure we do not have the exact errno. We must
* make due with return value from the mount process.
*/
int
do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts, int flags)
{
const char *src = zfs_get_name(zhp);
int error = 0;
if (!libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) {
char badopt[MNT_LINE_MAX] = {0};
unsigned long mntflags = flags, zfsflags;
char myopts[MNT_LINE_MAX] = {0};
if (zfs_parse_mount_options(opts, &mntflags,
&zfsflags, 0, badopt, NULL)) {
return (EINVAL);
}
strlcat(myopts, opts, MNT_LINE_MAX);
zfs_adjust_mount_options(zhp, mntpt, myopts, NULL);
if (mount(src, mntpt, MNTTYPE_ZFS, mntflags, myopts)) {
return (errno);
}
} else {
char *argv[9] = {
"/bin/mount",
"--no-canonicalize",
"-t", MNTTYPE_ZFS,
"-o", opts,
(char *)src,
(char *)mntpt,
(char *)NULL };
/* Return only the most critical mount error */
error = libzfs_run_process(argv[0], argv,
STDOUT_VERBOSE|STDERR_VERBOSE);
if (error) {
if (error & MOUNT_FILEIO) {
error = EIO;
} else if (error & MOUNT_USER) {
error = EINTR;
} else if (error & MOUNT_SOFTWARE) {
error = EPIPE;
} else if (error & MOUNT_BUSY) {
error = EBUSY;
} else if (error & MOUNT_SYSERR) {
error = EAGAIN;
} else if (error & MOUNT_USAGE) {
error = EINVAL;
} else
error = ENXIO; /* Generic error */
}
}
return (error);
}
int
do_unmount(const char *mntpt, int flags)
{
if (!libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) {
return (umount2(mntpt, flags));
}
char force_opt[] = "-f";
char lazy_opt[] = "-l";
char *argv[7] = {
"/bin/umount",
"-t", MNTTYPE_ZFS,
NULL, NULL, NULL, NULL };
int rc, count = 3;
if (flags & MS_FORCE) {
argv[count] = force_opt;
count++;
}
if (flags & MS_DETACH) {
argv[count] = lazy_opt;
count++;
}
argv[count] = (char *)mntpt;
rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
return (rc ? EINVAL : 0);
}
int
zfs_mount_delegation_check(void)
{
return ((geteuid() != 0) ? EACCES : 0);
}