1 files changed, 139 insertions, 0 deletions
diff --git a/pkg/sentry/vfs/testutil.go b/pkg/sentry/vfs/testutil.go
new file mode 100644
index 000000000..70b192ece
--- /dev/null
+++ b/pkg/sentry/vfs/testutil.go
@@ -0,0 +1,139 @@
+// Copyright 2019 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 vfs
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/syserror"
+)
+
+// FDTestFilesystemType is a test-only FilesystemType that produces Filesystems
+// for which all FilesystemImpl methods taking a path return EPERM. It is used
+// to produce Mounts and Dentries for testing of FileDescriptionImpls that do
+// not depend on their originating Filesystem.
+type FDTestFilesystemType struct{}
+
+// FDTestFilesystem is a test-only FilesystemImpl produced by
+// FDTestFilesystemType.
+type FDTestFilesystem struct {
+	vfsfs Filesystem
+}
+
+// NewFilesystem implements FilesystemType.NewFilesystem.
+func (fstype FDTestFilesystemType) NewFilesystem(ctx context.Context, creds *auth.Credentials, source string, opts NewFilesystemOptions) (*Filesystem, *Dentry, error) {
+	var fs FDTestFilesystem
+	fs.vfsfs.Init(&fs)
+	return &fs.vfsfs, fs.NewDentry(), nil
+}
+
+// Release implements FilesystemImpl.Release.
+func (fs *FDTestFilesystem) Release() {
+}
+
+// Sync implements FilesystemImpl.Sync.
+func (fs *FDTestFilesystem) Sync(ctx context.Context) error {
+	return nil
+}
+
+// GetDentryAt implements FilesystemImpl.GetDentryAt.
+func (fs *FDTestFilesystem) GetDentryAt(ctx context.Context, rp *ResolvingPath, opts GetDentryOptions) (*Dentry, error) {
+	return nil, syserror.EPERM
+}
+
+// LinkAt implements FilesystemImpl.LinkAt.
+func (fs *FDTestFilesystem) LinkAt(ctx context.Context, rp *ResolvingPath, vd VirtualDentry) error {
+	return syserror.EPERM
+}
+
+// MkdirAt implements FilesystemImpl.MkdirAt.
+func (fs *FDTestFilesystem) MkdirAt(ctx context.Context, rp *ResolvingPath, opts MkdirOptions) error {
+	return syserror.EPERM
+}
+
+// MknodAt implements FilesystemImpl.MknodAt.
+func (fs *FDTestFilesystem) MknodAt(ctx context.Context, rp *ResolvingPath, opts MknodOptions) error {
+	return syserror.EPERM
+}
+
+// OpenAt implements FilesystemImpl.OpenAt.
+func (fs *FDTestFilesystem) OpenAt(ctx context.Context, rp *ResolvingPath, opts OpenOptions) (*FileDescription, error) {
+	return nil, syserror.EPERM
+}
+
+// ReadlinkAt implements FilesystemImpl.ReadlinkAt.
+func (fs *FDTestFilesystem) ReadlinkAt(ctx context.Context, rp *ResolvingPath) (string, error) {
+	return "", syserror.EPERM
+}
+
+// RenameAt implements FilesystemImpl.RenameAt.
+func (fs *FDTestFilesystem) RenameAt(ctx context.Context, rp *ResolvingPath, vd VirtualDentry, opts RenameOptions) error {
+	return syserror.EPERM
+}
+
+// RmdirAt implements FilesystemImpl.RmdirAt.
+func (fs *FDTestFilesystem) RmdirAt(ctx context.Context, rp *ResolvingPath) error {
+	return syserror.EPERM
+}
+
+// SetStatAt implements FilesystemImpl.SetStatAt.
+func (fs *FDTestFilesystem) SetStatAt(ctx context.Context, rp *ResolvingPath, opts SetStatOptions) error {
+	return syserror.EPERM
+}
+
+// StatAt implements FilesystemImpl.StatAt.
+func (fs *FDTestFilesystem) StatAt(ctx context.Context, rp *ResolvingPath, opts StatOptions) (linux.Statx, error) {
+	return linux.Statx{}, syserror.EPERM
+}
+
+// StatFSAt implements FilesystemImpl.StatFSAt.
+func (fs *FDTestFilesystem) StatFSAt(ctx context.Context, rp *ResolvingPath) (linux.Statfs, error) {
+	return linux.Statfs{}, syserror.EPERM
+}
+
+// SymlinkAt implements FilesystemImpl.SymlinkAt.
+func (fs *FDTestFilesystem) SymlinkAt(ctx context.Context, rp *ResolvingPath, target string) error {
+	return syserror.EPERM
+}
+
+// UnlinkAt implements FilesystemImpl.UnlinkAt.
+func (fs *FDTestFilesystem) UnlinkAt(ctx context.Context, rp *ResolvingPath) error {
+	return syserror.EPERM
+}
+
+type fdTestDentry struct {
+	vfsd Dentry
+}
+
+// NewDentry returns a new Dentry.
+func (fs *FDTestFilesystem) NewDentry() *Dentry {
+	var d fdTestDentry
+	d.vfsd.Init(&d)
+	return &d.vfsd
+}
+
+// IncRef implements DentryImpl.IncRef.
+func (d *fdTestDentry) IncRef(vfsfs *Filesystem) {
+}
+
+// TryIncRef implements DentryImpl.TryIncRef.
+func (d *fdTestDentry) TryIncRef(vfsfs *Filesystem) bool {
+	return true
+}
+
+// DecRef implements DentryImpl.DecRef.
+func (d *fdTestDentry) DecRef(vfsfs *Filesystem) {
+}