Merge branch 'master' into ip-forwarding

- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward

1 files changed, 156 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go b/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go
new file mode 100644
index 000000000..6f3e3ae6f
--- /dev/null
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs_test.go
@@ -0,0 +1,156 @@
+// 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 tmpfs
+
+import (
+	"fmt"
+	"sync/atomic"
+
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/fspath"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
+// nextFileID is used to generate unique file names.
+var nextFileID int64
+
+// newTmpfsRoot creates a new tmpfs mount, and returns the root. If the error
+// is not nil, then cleanup should be called when the root is no longer needed.
+func newTmpfsRoot(ctx context.Context) (*vfs.VirtualFilesystem, vfs.VirtualDentry, func(), error) {
+	creds := auth.CredentialsFromContext(ctx)
+
+	vfsObj := &vfs.VirtualFilesystem{}
+	if err := vfsObj.Init(ctx); err != nil {
+		return nil, vfs.VirtualDentry{}, nil, fmt.Errorf("VFS init: %v", err)
+	}
+
+	vfsObj.MustRegisterFilesystemType("tmpfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+	})
+	mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{})
+	if err != nil {
+		return nil, vfs.VirtualDentry{}, nil, fmt.Errorf("failed to create tmpfs root mount: %v", err)
+	}
+	root := mntns.Root()
+	return vfsObj, root, func() {
+		root.DecRef(ctx)
+		mntns.DecRef(ctx)
+	}, nil
+}
+
+// newFileFD creates a new file in a new tmpfs mount, and returns the FD. If
+// the returned err is not nil, then cleanup should be called when the FD is no
+// longer needed.
+func newFileFD(ctx context.Context, mode linux.FileMode) (*vfs.FileDescription, func(), error) {
+	creds := auth.CredentialsFromContext(ctx)
+	vfsObj, root, cleanup, err := newTmpfsRoot(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	filename := fmt.Sprintf("tmpfs-test-file-%d", atomic.AddInt64(&nextFileID, 1))
+
+	// Create the file that will be write/read.
+	fd, err := vfsObj.OpenAt(ctx, creds, &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(filename),
+	}, &vfs.OpenOptions{
+		Flags: linux.O_RDWR | linux.O_CREAT | linux.O_EXCL,
+		Mode:  linux.ModeRegular | mode,
+	})
+	if err != nil {
+		cleanup()
+		return nil, nil, fmt.Errorf("failed to create file %q: %v", filename, err)
+	}
+
+	return fd, cleanup, nil
+}
+
+// newDirFD is like newFileFD, but for directories.
+func newDirFD(ctx context.Context, mode linux.FileMode) (*vfs.FileDescription, func(), error) {
+	creds := auth.CredentialsFromContext(ctx)
+	vfsObj, root, cleanup, err := newTmpfsRoot(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	dirname := fmt.Sprintf("tmpfs-test-dir-%d", atomic.AddInt64(&nextFileID, 1))
+
+	// Create the dir.
+	if err := vfsObj.MkdirAt(ctx, creds, &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(dirname),
+	}, &vfs.MkdirOptions{
+		Mode: linux.ModeDirectory | mode,
+	}); err != nil {
+		cleanup()
+		return nil, nil, fmt.Errorf("failed to create directory %q: %v", dirname, err)
+	}
+
+	// Open the dir and return it.
+	fd, err := vfsObj.OpenAt(ctx, creds, &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(dirname),
+	}, &vfs.OpenOptions{
+		Flags: linux.O_RDONLY | linux.O_DIRECTORY,
+	})
+	if err != nil {
+		cleanup()
+		return nil, nil, fmt.Errorf("failed to open directory %q: %v", dirname, err)
+	}
+
+	return fd, cleanup, nil
+}
+
+// newPipeFD is like newFileFD, but for pipes.
+func newPipeFD(ctx context.Context, mode linux.FileMode) (*vfs.FileDescription, func(), error) {
+	creds := auth.CredentialsFromContext(ctx)
+	vfsObj, root, cleanup, err := newTmpfsRoot(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	name := fmt.Sprintf("tmpfs-test-%d", atomic.AddInt64(&nextFileID, 1))
+
+	if err := vfsObj.MknodAt(ctx, creds, &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(name),
+	}, &vfs.MknodOptions{
+		Mode: linux.ModeNamedPipe | mode,
+	}); err != nil {
+		cleanup()
+		return nil, nil, fmt.Errorf("failed to create pipe %q: %v", name, err)
+	}
+
+	fd, err := vfsObj.OpenAt(ctx, creds, &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(name),
+	}, &vfs.OpenOptions{
+		Flags: linux.O_RDWR,
+	})
+	if err != nil {
+		cleanup()
+		return nil, nil, fmt.Errorf("failed to open pipe %q: %v", name, err)
+	}
+
+	return fd, cleanup, nil
+}