1 files changed, 0 insertions, 286 deletions
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go
deleted file mode 100644
index c205e6a0b..000000000
--- a/pkg/sentry/fsimpl/host/host.go
+++ /dev/null
@@ -1,286 +0,0 @@
-// Copyright 2020 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package host provides a filesystem implementation for host files imported as
-// file descriptors.
-package host
-
-import (
-	"errors"
-	"fmt"
-	"syscall"
-
-	"golang.org/x/sys/unix"
-	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/context"
-	"gvisor.dev/gvisor/pkg/log"
-	"gvisor.dev/gvisor/pkg/refs"
-	"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
-	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
-	"gvisor.dev/gvisor/pkg/sentry/vfs"
-	"gvisor.dev/gvisor/pkg/sync"
-	"gvisor.dev/gvisor/pkg/syserror"
-)
-
-// filesystem implements vfs.FilesystemImpl.
-type filesystem struct {
-	kernfs.Filesystem
-}
-
-// ImportFD sets up and returns a vfs.FileDescription from a donated fd.
-func ImportFD(mnt *vfs.Mount, hostFD int, ownerUID auth.KUID, ownerGID auth.KGID, isTTY bool) (*vfs.FileDescription, error) {
-	// Must be importing to a mount of host.filesystem.
-	fs, ok := mnt.Filesystem().Impl().(*filesystem)
-	if !ok {
-		return nil, fmt.Errorf("can't import host FDs into filesystems of type %T", mnt.Filesystem().Impl())
-	}
-
-	// Retrieve metadata.
-	var s syscall.Stat_t
-	if err := syscall.Fstat(hostFD, &s); err != nil {
-		return nil, err
-	}
-
-	fileMode := linux.FileMode(s.Mode)
-	fileType := fileMode.FileType()
-	// Pipes, character devices, and sockets can return EWOULDBLOCK for
-	// operations that would block.
-	isStream := fileType == syscall.S_IFIFO || fileType == syscall.S_IFCHR || fileType == syscall.S_IFSOCK
-
-	i := &inode{
-		hostFD:   hostFD,
-		isStream: isStream,
-		isTTY:    isTTY,
-		ino:      fs.NextIno(),
-		mode:     fileMode,
-		uid:      ownerUID,
-		gid:      ownerGID,
-	}
-
-	d := &kernfs.Dentry{}
-	d.Init(i)
-	// i.open will take a reference on d.
-	defer d.DecRef()
-
-	return i.open(d.VFSDentry(), mnt)
-}
-
-// inode implements kernfs.Inode.
-type inode struct {
-	kernfs.InodeNotDirectory
-	kernfs.InodeNotSymlink
-
-	// When the reference count reaches zero, the host fd is closed.
-	refs.AtomicRefCount
-
-	// hostFD contains the host fd that this file was originally created from,
-	// which must be available at time of restore.
-	//
-	// This field is initialized at creation time and is immutable.
-	hostFD int
-
-	// isStream is true if the host fd points to a file representing a stream,
-	// e.g. a socket or a pipe. Such files are not seekable and can return
-	// EWOULDBLOCK for I/O operations.
-	//
-	// This field is initialized at creation time and is immutable.
-	isStream bool
-
-	// isTTY is true if this file represents a TTY.
-	//
-	// This field is initialized at creation time and is immutable.
-	isTTY bool
-
-	// ino is an inode number unique within this filesystem.
-	ino uint64
-
-	// mu protects the inode metadata below.
-	mu sync.Mutex
-
-	// mode is the file mode of this inode. Note that this value may become out
-	// of date if the mode is changed on the host, e.g. with chmod.
-	mode linux.FileMode
-
-	// uid and gid of the file owner. Note that these refer to the owner of the
-	// file created on import, not the fd on the host.
-	uid auth.KUID
-	gid auth.KGID
-}
-
-// Note that these flags may become out of date, since they can be modified
-// on the host, e.g. with fcntl.
-func fileFlagsFromHostFD(fd int) (int, error) {
-	flags, err := unix.FcntlInt(uintptr(fd), syscall.F_GETFL, 0)
-	if err != nil {
-		log.Warningf("Failed to get file flags for donated FD %d: %v", fd, err)
-		return 0, err
-	}
-	// TODO(gvisor.dev/issue/1672): implement behavior corresponding to these allowed flags.
-	flags &= syscall.O_ACCMODE | syscall.O_DIRECT | syscall.O_NONBLOCK | syscall.O_DSYNC | syscall.O_SYNC | syscall.O_APPEND
-	return flags, nil
-}
-
-// CheckPermissions implements kernfs.Inode.
-func (i *inode) CheckPermissions(ctx context.Context, creds *auth.Credentials, atx vfs.AccessTypes) error {
-	return vfs.GenericCheckPermissions(creds, atx, false /* isDir */, uint16(i.mode), i.uid, i.gid)
-}
-
-// Mode implements kernfs.Inode.
-func (i *inode) Mode() linux.FileMode {
-	return i.mode
-}
-
-// Stat implements kernfs.Inode.
-func (i *inode) Stat(_ *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
-	var s unix.Statx_t
-	if err := unix.Statx(i.hostFD, "", int(unix.AT_EMPTY_PATH|opts.Sync), int(opts.Mask), &s); err != nil {
-		return linux.Statx{}, err
-	}
-	ls := unixToLinuxStatx(s)
-
-	// Use our own internal inode number and file owner.
-	//
-	// TODO(gvisor.dev/issue/1672): Use a kernfs-specific device number as well.
-	// If we use the device number from the host, it may collide with another
-	// sentry-internal device number. We handle device/inode numbers without
-	// relying on the host to prevent collisions.
-	ls.Ino = i.ino
-	ls.UID = uint32(i.uid)
-	ls.GID = uint32(i.gid)
-
-	// Update file mode from the host.
-	i.mode = linux.FileMode(ls.Mode)
-
-	return ls, nil
-}
-
-// SetStat implements kernfs.Inode.
-func (i *inode) SetStat(_ *vfs.Filesystem, opts vfs.SetStatOptions) error {
-	s := opts.Stat
-
-	m := s.Mask
-	if m == 0 {
-		return nil
-	}
-	if m&(linux.STATX_UID|linux.STATX_GID) != 0 {
-		return syserror.EPERM
-	}
-	if m&linux.STATX_MODE != 0 {
-		if err := syscall.Fchmod(i.hostFD, uint32(s.Mode)); err != nil {
-			return err
-		}
-		i.mode = linux.FileMode(s.Mode)
-	}
-	if m&linux.STATX_SIZE != 0 {
-		if err := syscall.Ftruncate(i.hostFD, int64(s.Size)); err != nil {
-			return err
-		}
-	}
-	if m&(linux.STATX_ATIME|linux.STATX_MTIME) != 0 {
-		timestamps := []unix.Timespec{
-			toTimespec(s.Atime, m&linux.STATX_ATIME == 0),
-			toTimespec(s.Mtime, m&linux.STATX_MTIME == 0),
-		}
-		if err := unix.UtimesNanoAt(i.hostFD, "", timestamps, unix.AT_EMPTY_PATH); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// DecRef implements kernfs.Inode.
-func (i *inode) DecRef() {
-	i.AtomicRefCount.DecRefWithDestructor(i.Destroy)
-}
-
-// Destroy implements kernfs.Inode.
-func (i *inode) Destroy() {
-	if err := unix.Close(i.hostFD); err != nil {
-		log.Warningf("failed to close host fd %d: %v", i.hostFD, err)
-	}
-}
-
-// Open implements kernfs.Inode.
-func (i *inode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	return i.open(vfsd, rp.Mount())
-}
-
-func (i *inode) open(d *vfs.Dentry, mnt *vfs.Mount) (*vfs.FileDescription, error) {
-
-	fileType := i.mode.FileType()
-	if fileType == syscall.S_IFSOCK {
-		if i.isTTY {
-			return nil, errors.New("cannot use host socket as TTY")
-		}
-		// TODO(gvisor.dev/issue/1672): support importing sockets.
-		return nil, errors.New("importing host sockets not supported")
-	}
-
-	if i.isTTY {
-		// TODO(gvisor.dev/issue/1672): support importing host fd as TTY.
-		return nil, errors.New("importing host fd as TTY not supported")
-	}
-
-	// For simplicity, set offset to 0. Technically, we should
-	// only set to 0 on files that are not seekable (sockets, pipes, etc.),
-	// and use the offset from the host fd otherwise.
-	fd := &defaultFileFD{
-		fileDescription: fileDescription{
-			inode: i,
-		},
-		canMap: canMap(uint32(fileType)),
-		mu:     sync.Mutex{},
-		offset: 0,
-	}
-
-	vfsfd := &fd.vfsfd
-	flags, err := fileFlagsFromHostFD(i.hostFD)
-	if err != nil {
-		return nil, err
-	}
-
-	if err := vfsfd.Init(fd, uint32(flags), mnt, d, &vfs.FileDescriptionOptions{}); err != nil {
-		return nil, err
-	}
-	return vfsfd, nil
-}
-
-// fileDescription is embedded by host fd implementations of FileDescriptionImpl.
-type fileDescription struct {
-	vfsfd vfs.FileDescription
-	vfs.FileDescriptionDefaultImpl
-
-	// inode is vfsfd.Dentry().Impl().(*kernfs.Dentry).Inode().(*inode), but
-	// cached to reduce indirections and casting. fileDescription does not hold
-	// a reference on the inode through the inode field (since one is already
-	// held via the Dentry).
-	//
-	// inode is immutable after fileDescription creation.
-	inode *inode
-}
-
-// SetStat implements vfs.FileDescriptionImpl.
-func (f *fileDescription) SetStat(_ context.Context, opts vfs.SetStatOptions) error {
-	return f.inode.SetStat(nil, opts)
-}
-
-// Stat implements vfs.FileDescriptionImpl.
-func (f *fileDescription) Stat(_ context.Context, opts vfs.StatOptions) (linux.Statx, error) {
-	return f.inode.Stat(nil, opts)
-}
-
-// Release implements vfs.FileDescriptionImpl.
-func (f *fileDescription) Release() {
-	// noop
-}