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/*
* 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 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
* Copyright 2016 Joyent, Inc.
*/
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Portions of this source code were derived from Berkeley 4.3 BSD
* under license from the Regents of the University of California.
*/
#include <sys/param.h>
#include <sys/isa_defs.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/cred.h>
#include <sys/user.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/pathname.h>
#include <sys/var.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/mode.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/poll.h>
#include <sys/kmem.h>
#include <sys/filio.h>
#include <sys/cmn_err.h>
#include <sys/policy.h>
#include <sys/zone.h>
#include <sys/debug.h>
#include <c2/audit.h>
#include <fs/fs_subr.h>
/*
* Change current working directory (".").
*/
static int chdirec(vnode_t *, boolean_t ischroot, boolean_t do_traverse);
int
chdir(char *fname)
{
vnode_t *vp;
int error;
int estale_retry = 0;
lookup:
if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
goto lookup;
return (set_errno(error));
}
error = chdirec(vp, B_FALSE, B_TRUE);
if (error) {
if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
goto lookup;
return (set_errno(error));
}
return (0);
}
/*
* File-descriptor based version of 'chdir'.
*/
int
fchdir(int fd)
{
vnode_t *vp;
file_t *fp;
int error;
if ((fp = getf(fd)) == NULL)
return (set_errno(EBADF));
vp = fp->f_vnode;
VN_HOLD(vp);
releasef(fd);
error = chdirec(vp, B_FALSE, B_FALSE);
if (error)
return (set_errno(error));
return (0);
}
/*
* Change notion of root ("/") directory.
*/
int
chroot(char *fname)
{
vnode_t *vp;
int error;
int estale_retry = 0;
lookup:
if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
goto lookup;
return (set_errno(error));
}
error = chdirec(vp, B_TRUE, B_TRUE);
if (error) {
if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
goto lookup;
return (set_errno(error));
}
return (0);
}
/*
* ++++++++++++++++++++++++
* ++ SunOS4.1 Buyback ++
* ++++++++++++++++++++++++
* Change root directory with a user given fd
*/
int
fchroot(int fd)
{
vnode_t *vp;
file_t *fp;
int error;
if ((fp = getf(fd)) == NULL)
return (set_errno(EBADF));
vp = fp->f_vnode;
VN_HOLD(vp);
releasef(fd);
error = chdirec(vp, B_TRUE, B_FALSE);
if (error)
return (set_errno(error));
return (0);
}
static int
chdirec_common(proc_t *pp, vnode_t *vp, boolean_t ischroot,
boolean_t do_traverse)
{
int error;
vnode_t *oldvp;
vnode_t **vpp;
refstr_t *cwd;
int newcwd = 1;
if (vp->v_type != VDIR) {
error = ENOTDIR;
goto bad;
}
if (error = VOP_ACCESS(vp, VEXEC, 0, CRED(), NULL))
goto bad;
/*
* The VOP_ACCESS() may have covered 'vp' with a new filesystem,
* if 'vp' is an autoFS vnode. Traverse the mountpoint so
* that we don't end up with a covered current directory.
*/
if (vn_mountedvfs(vp) != NULL && do_traverse) {
if (error = traverse(&vp))
goto bad;
}
/*
* Special chroot semantics: chroot is allowed if privileged
* or if the target is really a loopback mount of the root (or
* root of the zone) as determined by comparing dev and inode
* numbers
*/
if (ischroot) {
struct vattr tattr;
struct vattr rattr;
vnode_t *zonevp = pp->p_zone->zone_rootvp;
tattr.va_mask = AT_FSID|AT_NODEID;
if (error = VOP_GETATTR(vp, &tattr, 0, CRED(), NULL))
goto bad;
rattr.va_mask = AT_FSID|AT_NODEID;
if (error = VOP_GETATTR(zonevp, &rattr, 0, CRED(), NULL))
goto bad;
if ((tattr.va_fsid != rattr.va_fsid ||
tattr.va_nodeid != rattr.va_nodeid) &&
(error = secpolicy_chroot(CRED())) != 0)
goto bad;
vpp = &PTOU(pp)->u_rdir;
} else {
vpp = &PTOU(pp)->u_cdir;
}
/* update abs cwd/root path see c2/audit.c */
if (AU_AUDITING())
audit_chdirec(vp, vpp);
mutex_enter(&pp->p_lock);
/*
* This bit of logic prevents us from overwriting u_cwd if we are
* changing to the same directory. We set the cwd to NULL so that we
* don't try to do the lookup on the next call to getcwd().
*/
if (!ischroot && *vpp != NULL && vp != NULL && VN_CMP(*vpp, vp))
newcwd = 0;
oldvp = *vpp;
*vpp = vp;
if ((cwd = PTOU(pp)->u_cwd) != NULL && newcwd)
PTOU(pp)->u_cwd = NULL;
mutex_exit(&pp->p_lock);
if (cwd && newcwd)
refstr_rele(cwd);
if (oldvp)
VN_RELE(oldvp);
return (0);
bad:
VN_RELE(vp);
return (error);
}
int
chdir_proc(proc_t *pp, vnode_t *vp, boolean_t ischroot, boolean_t do_traverse)
{
return (chdirec_common(pp, vp, ischroot, do_traverse));
}
static int
chdirec(vnode_t *vp, boolean_t ischroot, boolean_t do_traverse)
{
return (chdirec_common(curproc, vp, ischroot, do_traverse));
}
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