This is xnu-11215.1.10. See this file in:
/*
* Copyright (c) 2019 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*-
* Portions Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* John Heidemann of the UCLA Ficus project.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)null_vnops.c 8.6 (Berkeley) 5/27/95
*
* Ancestors:
* @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92
* ...and...
* @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mount_internal.h>
#include <sys/namei.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <sys/vnode_internal.h>
#include <sys/xattr.h>
#include <sys/ubc.h>
#include <sys/types.h>
#include <sys/dirent.h>
#include "bindfs.h"
#define BIND_ROOT_INO 2
vop_t * bindfs_vnodeop_p = NULL;
static int
bindfs_default(__unused struct vnop_generic_args * args)
{
return ENOTSUP;
}
static int
bindfs_getattr(struct vnop_getattr_args * args)
{
int error;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
struct vnode * lowervp = BINDVPTOLOWERVP(args->a_vp);
error = vnode_getwithref(lowervp);
if (error == 0) {
error = VNOP_GETATTR(lowervp, args->a_vap, args->a_context);
vnode_put(lowervp);
if (error == 0) {
if (VATTR_IS_ACTIVE(args->a_vap, va_fsid)) {
/* fix up fsid so it doesn't say the underlying fs*/
VATTR_RETURN(args->a_vap, va_fsid, vfs_statfs(vnode_mount(args->a_vp))->f_fsid.val[0]);
}
if (VATTR_IS_ACTIVE(args->a_vap, va_fsid64)) {
/* fix up fsid so it doesn't say the underlying fs*/
VATTR_RETURN(args->a_vap, va_fsid64, vfs_statfs(vnode_mount(args->a_vp))->f_fsid);
}
struct vnode * parent = vnode_parent(args->a_vp);
if (vnode_isvroot(args->a_vp)) {
// We can use the lower answers for most questions about the root vnode but need to fix up a few things
if (VATTR_IS_ACTIVE(args->a_vap, va_fileid)) {
VATTR_RETURN(args->a_vap, va_fileid, BIND_ROOT_INO);
}
if (VATTR_IS_ACTIVE(args->a_vap, va_linkid)) {
VATTR_RETURN(args->a_vap, va_linkid, BIND_ROOT_INO);
}
if (VATTR_IS_ACTIVE(args->a_vap, va_parentid)) {
// The parent of the root is itself
VATTR_RETURN(args->a_vap, va_parentid, BIND_ROOT_INO);
}
} else if (parent != NULL && vnode_isvroot(parent)) {
if (VATTR_IS_ACTIVE(args->a_vap, va_parentid)) {
// This vnode's parent is the root.
VATTR_RETURN(args->a_vap, va_parentid, BIND_ROOT_INO);
}
}
}
}
return error;
}
static int
bindfs_open(struct vnop_open_args * args)
{
int error;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
vp = args->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_OPEN(lvp, args->a_mode, args->a_context);
vnode_put(lvp);
}
return error;
}
static int
bindfs_close(struct vnop_close_args * args)
{
int error;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
vp = args->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_CLOSE(lvp, args->a_fflag, args->a_context);
vnode_put(lvp);
}
return error;
}
/*
* We have to carry on the locking protocol on the bind layer vnodes
* as we progress through the tree. We also have to enforce read-only
* if this layer is mounted read-only.
*/
static int
bind_lookup(struct vnop_lookup_args * ap)
{
struct componentname * cnp = ap->a_cnp;
struct vnode * dvp = ap->a_dvp;
struct vnode *vp, *ldvp, *lvp;
struct mount * mp;
struct bind_mount * bind_mp;
int error;
BINDFSDEBUG("%s parent: %p component: %.*s\n", __FUNCTION__, ap->a_dvp, cnp->cn_namelen, cnp->cn_nameptr);
mp = vnode_mount(dvp);
/* rename and delete are not allowed. this is a read only file system */
if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME || cnp->cn_nameiop == CREATE) {
return EROFS;
}
bind_mp = MOUNTTOBINDMOUNT(mp);
// . and .. handling
if (cnp->cn_nameptr[0] == '.') {
if (cnp->cn_namelen == 1) {
vp = dvp;
} else if (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.') {
vp = (vnode_isvroot(dvp)) ? dvp : vnode_parent(dvp);
} else {
goto notdot;
}
error = vp ? vnode_get(vp) : ENOENT;
if (error == 0) {
*ap->a_vpp = vp;
}
return error;
}
notdot:
ldvp = BINDVPTOLOWERVP(dvp);
vp = lvp = NULL;
/*
* Hold ldvp. The reference on it, owned by dvp, is lost in
* case of dvp reclamation.
*/
error = vnode_getwithref(ldvp);
if (error) {
return error;
}
error = VNOP_LOOKUP(ldvp, &lvp, cnp, ap->a_context);
vnode_put(ldvp);
if ((error == 0 || error == EJUSTRETURN) && lvp != NULL) {
if (ldvp == lvp) {
vp = dvp;
error = vnode_get(vp);
} else {
error = bind_nodeget(mp, lvp, dvp, &vp, cnp, 0);
}
if (error == 0) {
*ap->a_vpp = vp;
}
/* if we got lvp, drop the iocount from VNOP_LOOKUP */
if (lvp != NULL) {
vnode_put(lvp);
}
}
return error;
}
/*
* Don't think this needs to do anything
*/
static int
bind_inactive(__unused struct vnop_inactive_args * ap)
{
BINDFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
return 0;
}
static int
bind_reclaim(struct vnop_reclaim_args * ap)
{
struct vnode * vp;
struct bind_node * xp;
struct vnode * lowervp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
vp = ap->a_vp;
xp = VTOBIND(vp);
lowervp = xp->bind_lowervp;
vnode_removefsref(vp);
bind_hashrem(xp);
vnode_rele(lowervp);
cache_purge(vp);
vnode_clearfsnode(vp);
kfree_type(struct bind_node, xp);
return 0;
}
/* Get dirent length padded to 4 byte alignment */
#define DIRENT_LEN(namelen) \
((sizeof(struct dirent) + (namelen + 1) - (__DARWIN_MAXNAMLEN + 1) + 3) & ~3)
/* Get the end of this dirent */
#define DIRENT_END(dep) \
(((char *)(dep)) + (dep)->d_reclen - 1)
static int
bindfs_readdir(struct vnop_readdir_args * ap)
{
struct vnode *vp, *lvp, *dvp;
int error;
uio_t uio = ap->a_uio;
BINDFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
/* assumption is that any vp that comes through here had to go through lookup
*/
if (ap->a_flags & (VNODE_READDIR_EXTENDED | VNODE_READDIR_REQSEEKOFF)) {
return EINVAL;
}
vp = ap->a_vp;
dvp = vnode_parent(vp);
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error != 0) {
goto lb_end;
}
if (vnode_isvroot(vp) || (dvp != NULL && vnode_isvroot(dvp))) {
size_t bufsize;
void * bufptr;
uio_t auio;
struct dirent *dep;
size_t bytesread;
bufsize = 3 * MIN((user_size_t)uio_resid(uio), 87371u) / 8;
bufptr = kalloc_data(bufsize, Z_WAITOK);
if (bufptr == NULL) {
vnode_put(lvp);
return ENOMEM;
}
auio = uio_create(1, 0, UIO_SYSSPACE, UIO_READ);
uio_addiov(auio, (uintptr_t)bufptr, bufsize);
uio_setoffset(auio, uio_offset(uio));
error = VNOP_READDIR(lvp, auio, ap->a_flags, ap->a_eofflag, ap->a_numdirent, ap->a_context);
vnode_put(lvp);
if (error != 0) {
goto lb_end;
}
dep = (struct dirent *)bufptr;
bytesread = bufsize - uio_resid(auio);
while (error == 0 && (char *)dep < ((char *)bufptr + bytesread)) {
if (DIRENT_END(dep) > ((char *)bufptr + bytesread) ||
DIRENT_LEN(dep->d_namlen) > dep->d_reclen) {
printf("%s: %s: Bad dirent received from directory %s\n", __func__,
vfs_statfs(vnode_mount(vp))->f_mntonname,
vp->v_name ? vp->v_name : "<unknown>");
error = EIO;
break;
}
if (dep->d_name[0] == '.') {
/* re-write the inode number for the mount root */
/* if vp is the mount root then . = 2 and .. = 2 */
/* if the parent of vp is the mount root then .. = 2 */
if ((vnode_isvroot(vp) && dep->d_namlen == 1) ||
(dep->d_namlen == 2 && dep->d_name[1] == '.')) {
dep->d_ino = BIND_ROOT_INO;
}
}
/* Copy entry64 to user's buffer. */
error = uiomove((caddr_t)dep, dep->d_reclen, uio);
/* Move to next entry. */
dep = (struct dirent *)((char *)dep + dep->d_reclen);
}
/* Update the real offset using the offset we got from VNOP_READDIR. */
if (error == 0) {
uio_setoffset(uio, uio_offset(auio));
}
uio_free(auio);
kfree_data(bufptr, bufsize);
} else {
error = VNOP_READDIR(lvp, ap->a_uio, ap->a_flags, ap->a_eofflag, ap->a_numdirent, ap->a_context);
vnode_put(lvp);
}
lb_end:
return error;
}
static int
bindfs_readlink(struct vnop_readlink_args * ap)
{
BINDFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
int error;
struct vnode *vp, *lvp;
vp = ap->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_READLINK(lvp, ap->a_uio, ap->a_context);
vnode_put(lvp);
if (error) {
printf("bindfs: readlink failed: %d\n", error);
}
}
return error;
}
static int
bindfs_pathconf(__unused struct vnop_pathconf_args * args)
{
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
return EINVAL;
}
static int
bindfs_fsync(__unused struct vnop_fsync_args * args)
{
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
return 0;
}
static int
bindfs_mmap(struct vnop_mmap_args * args)
{
int error;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
vp = args->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_MMAP(lvp, args->a_fflags, args->a_context);
vnode_put(lvp);
}
return error;
}
static int
bindfs_mnomap(struct vnop_mnomap_args * args)
{
int error;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
vp = args->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_MNOMAP(lvp, args->a_context);
vnode_put(lvp);
}
return error;
}
static int
bindfs_getxattr(struct vnop_getxattr_args * args)
{
int error;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
vp = args->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_GETXATTR(lvp, args->a_name, args->a_uio, args->a_size, args->a_options, args->a_context);
vnode_put(lvp);
}
return error;
}
static int
bindfs_listxattr(struct vnop_listxattr_args * args)
{
int error;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, args->a_vp);
vp = args->a_vp;
lvp = BINDVPTOLOWERVP(vp);
error = vnode_getwithref(lvp);
if (error == 0) {
error = VNOP_LISTXATTR(lvp, args->a_uio, args->a_size, args->a_options, args->a_context);
vnode_put(lvp);
}
return error;
}
/* relies on v1 paging */
static int
bindfs_pagein(struct vnop_pagein_args * ap)
{
int error = EIO;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
vp = ap->a_vp;
lvp = BINDVPTOLOWERVP(vp);
if (vnode_vtype(vp) != VREG) {
return ENOTSUP;
}
/*
* Ask VM/UBC/VFS to do our bidding
*/
if (vnode_getwithvid(lvp, BINDVPTOLOWERVID(vp)) == 0) {
vm_offset_t ioaddr;
uio_t auio;
kern_return_t kret;
off_t bytes_to_commit;
off_t lowersize;
upl_t upl = ap->a_pl;
user_ssize_t bytes_remaining = 0;
auio = uio_create(1, ap->a_f_offset, UIO_SYSSPACE, UIO_READ);
if (auio == NULL) {
error = EIO;
goto exit_no_unmap;
}
kret = ubc_upl_map(upl, &ioaddr);
if (KERN_SUCCESS != kret) {
panic("bindfs_pagein: ubc_upl_map() failed with (%d)", kret);
}
ioaddr += ap->a_pl_offset;
error = uio_addiov(auio, (user_addr_t)ioaddr, ap->a_size);
if (error) {
goto exit;
}
lowersize = ubc_getsize(lvp);
if (lowersize != ubc_getsize(vp)) {
(void)ubc_setsize(vp, lowersize); /* ignore failures, nothing can be done */
}
error = VNOP_READ(lvp, auio, ((ap->a_flags & UPL_IOSYNC) ? IO_SYNC : 0), ap->a_context);
bytes_remaining = uio_resid(auio);
if (bytes_remaining > 0 && bytes_remaining <= (user_ssize_t)ap->a_size) {
/* zero bytes that weren't read in to the upl */
bzero((void*)((uintptr_t)(ioaddr + ap->a_size - bytes_remaining)), (size_t) bytes_remaining);
}
exit:
kret = ubc_upl_unmap(upl);
if (KERN_SUCCESS != kret) {
panic("bindfs_pagein: ubc_upl_unmap() failed with (%d)", kret);
}
if (auio != NULL) {
uio_free(auio);
}
exit_no_unmap:
if ((ap->a_flags & UPL_NOCOMMIT) == 0) {
if (!error && (bytes_remaining >= 0) && (bytes_remaining <= (user_ssize_t)ap->a_size)) {
/* only commit what was read in (page aligned)*/
bytes_to_commit = ap->a_size - bytes_remaining;
if (bytes_to_commit) {
/* need to make sure bytes_to_commit and byte_remaining are page aligned before calling ubc_upl_commit_range*/
if (bytes_to_commit & PAGE_MASK) {
bytes_to_commit = (bytes_to_commit & (~PAGE_MASK)) + (PAGE_MASK + 1);
assert(bytes_to_commit <= (off_t)ap->a_size);
bytes_remaining = ap->a_size - bytes_to_commit;
}
ubc_upl_commit_range(upl, ap->a_pl_offset, (upl_size_t)bytes_to_commit, UPL_COMMIT_FREE_ON_EMPTY);
}
/* abort anything thats left */
if (bytes_remaining) {
ubc_upl_abort_range(upl, ap->a_pl_offset + (upl_offset_t)bytes_to_commit, (upl_size_t)bytes_remaining, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);
}
} else {
ubc_upl_abort_range(upl, ap->a_pl_offset, (upl_size_t)ap->a_size, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);
}
}
vnode_put(lvp);
} else if ((ap->a_flags & UPL_NOCOMMIT) == 0) {
ubc_upl_abort_range(ap->a_pl, ap->a_pl_offset, (upl_size_t)ap->a_size, UPL_ABORT_ERROR | UPL_ABORT_FREE_ON_EMPTY);
}
return error;
}
static int
bindfs_read(struct vnop_read_args * ap)
{
int error = EIO;
struct vnode *vp, *lvp;
BINDFSDEBUG("%s %p\n", __FUNCTION__, ap->a_vp);
vp = ap->a_vp;
lvp = BINDVPTOLOWERVP(vp);
/*
* First some house keeping
*/
if (vnode_getwithvid(lvp, BINDVPTOLOWERVID(vp)) == 0) {
if (!vnode_isreg(lvp) && !vnode_islnk(lvp)) {
error = EPERM;
goto end;
}
if (uio_resid(ap->a_uio) == 0) {
error = 0;
goto end;
}
/*
* Now ask VM/UBC/VFS to do our bidding
*/
error = VNOP_READ(lvp, ap->a_uio, ap->a_ioflag, ap->a_context);
if (error) {
printf("bindfs: VNOP_READ failed: %d\n", error);
}
end:
vnode_put(lvp);
}
return error;
}
/*
* Global vfs data structures
*/
static const struct vnodeopv_entry_desc bindfs_vnodeop_entries[] = {
{.opve_op = &vnop_default_desc, .opve_impl = (vop_t)bindfs_default}, /* default */
{.opve_op = &vnop_getattr_desc, .opve_impl = (vop_t)bindfs_getattr}, /* getattr */
{.opve_op = &vnop_open_desc, .opve_impl = (vop_t)bindfs_open}, /* open */
{.opve_op = &vnop_close_desc, .opve_impl = (vop_t)bindfs_close}, /* close */
{.opve_op = &vnop_inactive_desc, .opve_impl = (vop_t)bind_inactive}, /* inactive */
{.opve_op = &vnop_reclaim_desc, .opve_impl = (vop_t)bind_reclaim}, /* reclaim */
{.opve_op = &vnop_lookup_desc, .opve_impl = (vop_t)bind_lookup}, /* lookup */
{.opve_op = &vnop_readdir_desc, .opve_impl = (vop_t)bindfs_readdir}, /* readdir */
{.opve_op = &vnop_readlink_desc, .opve_impl = (vop_t)bindfs_readlink}, /* readlink */
{.opve_op = &vnop_pathconf_desc, .opve_impl = (vop_t)bindfs_pathconf}, /* pathconf */
{.opve_op = &vnop_fsync_desc, .opve_impl = (vop_t)bindfs_fsync}, /* fsync */
{.opve_op = &vnop_mmap_desc, .opve_impl = (vop_t)bindfs_mmap}, /* mmap */
{.opve_op = &vnop_mnomap_desc, .opve_impl = (vop_t)bindfs_mnomap}, /* mnomap */
{.opve_op = &vnop_getxattr_desc, .opve_impl = (vop_t)bindfs_getxattr}, /* getxattr */
{.opve_op = &vnop_pagein_desc, .opve_impl = (vop_t)bindfs_pagein}, /* pagein */
{.opve_op = &vnop_read_desc, .opve_impl = (vop_t)bindfs_read}, /* read */
{.opve_op = &vnop_listxattr_desc, .opve_impl = (vop_t)bindfs_listxattr}, /* listxattr */
{.opve_op = NULL, .opve_impl = NULL},
};
const struct vnodeopv_desc bindfs_vnodeop_opv_desc = {.opv_desc_vector_p = &bindfs_vnodeop_p, .opv_desc_ops = bindfs_vnodeop_entries};
//BINDFS Specific helper function
int
bindfs_getbackingvnode(vnode_t in_vp, vnode_t* out_vpp)
{
int result = EINVAL;
if (out_vpp == NULL || in_vp == NULL) {
goto end;
}
struct vfsstatfs * sp = NULL;
mount_t mp = vnode_mount(in_vp);
sp = vfs_statfs(mp);
//If this isn't a bindfs vnode or it is but it's a special vnode
if (strcmp(sp->f_fstypename, "bindfs") != 0) {
*out_vpp = NULLVP;
result = ENOENT;
goto end;
}
vnode_t lvp = BINDVPTOLOWERVP(in_vp);
if ((result = vnode_getwithvid(lvp, BINDVPTOLOWERVID(in_vp)))) {
goto end;
}
*out_vpp = lvp;
end:
return result;
}