1 files changed, 480 insertions, 0 deletions
diff --git a/runsc/container/console_test.go b/runsc/container/console_test.go
new file mode 100644
index 000000000..3813c6b93
--- /dev/null
+++ b/runsc/container/console_test.go
@@ -0,0 +1,480 @@
+// Copyright 2018 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 container
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/kr/pty"
+	"golang.org/x/sys/unix"
+	"gvisor.dev/gvisor/pkg/sentry/control"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sync"
+	"gvisor.dev/gvisor/pkg/test/testutil"
+	"gvisor.dev/gvisor/pkg/unet"
+	"gvisor.dev/gvisor/pkg/urpc"
+)
+
+// socketPath creates a path inside bundleDir and ensures that the returned
+// path is under 108 charactors (the unix socket path length limit),
+// relativizing the path if necessary.
+func socketPath(bundleDir string) (string, error) {
+	path := filepath.Join(bundleDir, "socket")
+	cwd, err := os.Getwd()
+	if err != nil {
+		return "", fmt.Errorf("error getting cwd: %v", err)
+	}
+	relPath, err := filepath.Rel(cwd, path)
+	if err != nil {
+		return "", fmt.Errorf("error getting relative path for %q from cwd %q: %v", path, cwd, err)
+	}
+	if len(path) > len(relPath) {
+		path = relPath
+	}
+	const maxPathLen = 108
+	if len(path) > maxPathLen {
+		return "", fmt.Errorf("could not get socket path under length limit %d: %s", maxPathLen, path)
+	}
+	return path, nil
+}
+
+// createConsoleSocket creates a socket at the given path that will receive a
+// console fd from the sandbox. If an error occurs, t.Fatalf will be called.
+// The function returning should be deferred as cleanup.
+func createConsoleSocket(t *testing.T, path string) (*unet.ServerSocket, func()) {
+	t.Helper()
+	srv, err := unet.BindAndListen(path, false)
+	if err != nil {
+		t.Fatalf("error binding and listening to socket %q: %v", path, err)
+	}
+
+	cleanup := func() {
+		// Log errors; nothing can be done.
+		if err := srv.Close(); err != nil {
+			t.Logf("error closing socket %q: %v", path, err)
+		}
+		if err := os.Remove(path); err != nil {
+			t.Logf("error removing socket %q: %v", path, err)
+		}
+	}
+
+	return srv, cleanup
+}
+
+// receiveConsolePTY accepts a connection on the server socket and reads fds.
+// It fails if more than one FD is received, or if the FD is not a PTY. It
+// returns the PTY master file.
+func receiveConsolePTY(srv *unet.ServerSocket) (*os.File, error) {
+	sock, err := srv.Accept()
+	if err != nil {
+		return nil, fmt.Errorf("error accepting socket connection: %v", err)
+	}
+
+	// Allow 3 fds to be received.  We only expect 1.
+	r := sock.Reader(true /* blocking */)
+	r.EnableFDs(1)
+
+	// The socket is closed right after sending the FD, so EOF is
+	// an allowed error.
+	b := [][]byte{{}}
+	if _, err := r.ReadVec(b); err != nil && err != io.EOF {
+		return nil, fmt.Errorf("error reading from socket connection: %v", err)
+	}
+
+	// We should have gotten a control message.
+	fds, err := r.ExtractFDs()
+	if err != nil {
+		return nil, fmt.Errorf("error extracting fds from socket connection: %v", err)
+	}
+	if len(fds) != 1 {
+		return nil, fmt.Errorf("got %d fds from socket, wanted 1", len(fds))
+	}
+
+	// Verify that the fd is a terminal.
+	if _, err := unix.IoctlGetTermios(fds[0], unix.TCGETS); err != nil {
+		return nil, fmt.Errorf("fd is not a terminal (ioctl TGGETS got %v)", err)
+	}
+
+	return os.NewFile(uintptr(fds[0]), "pty_master"), nil
+}
+
+// Test that an pty FD is sent over the console socket if one is provided.
+func TestConsoleSocket(t *testing.T) {
+	for name, conf := range configsWithVFS2(t, all...) {
+		t.Run(name, func(t *testing.T) {
+			spec := testutil.NewSpecWithArgs("true")
+			_, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf)
+			if err != nil {
+				t.Fatalf("error setting up container: %v", err)
+			}
+			defer cleanup()
+
+			sock, err := socketPath(bundleDir)
+			if err != nil {
+				t.Fatalf("error getting socket path: %v", err)
+			}
+			srv, cleanup := createConsoleSocket(t, sock)
+			defer cleanup()
+
+			// Create the container and pass the socket name.
+			args := Args{
+				ID:            testutil.RandomContainerID(),
+				Spec:          spec,
+				BundleDir:     bundleDir,
+				ConsoleSocket: sock,
+			}
+			c, err := New(conf, args)
+			if err != nil {
+				t.Fatalf("error creating container: %v", err)
+			}
+			defer c.Destroy()
+
+			// Make sure we get a console PTY.
+			ptyMaster, err := receiveConsolePTY(srv)
+			if err != nil {
+				t.Fatalf("error receiving console FD: %v", err)
+			}
+			ptyMaster.Close()
+		})
+	}
+}
+
+// Test that job control signals work on a console created with "exec -ti".
+func TestJobControlSignalExec(t *testing.T) {
+	spec := testutil.NewSpecWithArgs("/bin/sleep", "10000")
+	conf := testutil.TestConfig(t)
+
+	_, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf)
+	if err != nil {
+		t.Fatalf("error setting up container: %v", err)
+	}
+	defer cleanup()
+
+	// Create and start the container.
+	args := Args{
+		ID:        testutil.RandomContainerID(),
+		Spec:      spec,
+		BundleDir: bundleDir,
+	}
+	c, err := New(conf, args)
+	if err != nil {
+		t.Fatalf("error creating container: %v", err)
+	}
+	defer c.Destroy()
+	if err := c.Start(conf); err != nil {
+		t.Fatalf("error starting container: %v", err)
+	}
+
+	// Create a pty master/slave. The slave will be passed to the exec
+	// process.
+	ptyMaster, ptySlave, err := pty.Open()
+	if err != nil {
+		t.Fatalf("error opening pty: %v", err)
+	}
+	defer ptyMaster.Close()
+	defer ptySlave.Close()
+
+	// Exec bash and attach a terminal. Note that occasionally /bin/sh
+	// may be a different shell or have a different configuration (such
+	// as disabling interactive mode and job control). Since we want to
+	// explicitly test interactive mode, use /bin/bash. See b/116981926.
+	execArgs := &control.ExecArgs{
+		Filename: "/bin/bash",
+		// Don't let bash execute from profile or rc files, otherwise
+		// our PID counts get messed up.
+		Argv: []string{"/bin/bash", "--noprofile", "--norc"},
+		// Pass the pty slave as FD 0, 1, and 2.
+		FilePayload: urpc.FilePayload{
+			Files: []*os.File{ptySlave, ptySlave, ptySlave},
+		},
+		StdioIsPty: true,
+	}
+
+	pid, err := c.Execute(execArgs)
+	if err != nil {
+		t.Fatalf("error executing: %v", err)
+	}
+	if pid != 2 {
+		t.Fatalf("exec got pid %d, wanted %d", pid, 2)
+	}
+
+	// Make sure all the processes are running.
+	expectedPL := []*control.Process{
+		// Root container process.
+		{PID: 1, Cmd: "sleep", Threads: []kernel.ThreadID{1}},
+		// Bash from exec process.
+		{PID: 2, Cmd: "bash", Threads: []kernel.ThreadID{2}},
+	}
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Error(err)
+	}
+
+	// Execute sleep.
+	ptyMaster.Write([]byte("sleep 100\n"))
+
+	// Wait for it to start. Sleep's PPID is bash's PID.
+	expectedPL = append(expectedPL, &control.Process{PID: 3, PPID: 2, Cmd: "sleep", Threads: []kernel.ThreadID{3}})
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Error(err)
+	}
+
+	// Send a SIGTERM to the foreground process for the exec PID. Note that
+	// although we pass in the PID of "bash", it should actually terminate
+	// "sleep", since that is the foreground process.
+	if err := c.Sandbox.SignalProcess(c.ID, pid, syscall.SIGTERM, true /* fgProcess */); err != nil {
+		t.Fatalf("error signaling container: %v", err)
+	}
+
+	// Sleep process should be gone.
+	expectedPL = expectedPL[:len(expectedPL)-1]
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Error(err)
+	}
+
+	// Sleep is dead, but it may take more time for bash to notice and
+	// change the foreground process back to itself. We know it is done
+	// when bash writes "Terminated" to the pty.
+	if err := testutil.WaitUntilRead(ptyMaster, "Terminated", nil, 5*time.Second); err != nil {
+		t.Fatalf("bash did not take over pty: %v", err)
+	}
+
+	// Send a SIGKILL to the foreground process again. This time "bash"
+	// should be killed. We use SIGKILL instead of SIGTERM or SIGINT
+	// because bash ignores those.
+	if err := c.Sandbox.SignalProcess(c.ID, pid, syscall.SIGKILL, true /* fgProcess */); err != nil {
+		t.Fatalf("error signaling container: %v", err)
+	}
+	expectedPL = expectedPL[:1]
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Error(err)
+	}
+
+	// Make sure the process indicates it was killed by a SIGKILL.
+	ws, err := c.WaitPID(pid)
+	if err != nil {
+		t.Errorf("waiting on container failed: %v", err)
+	}
+	if !ws.Signaled() {
+		t.Error("ws.Signaled() got false, want true")
+	}
+	if got, want := ws.Signal(), syscall.SIGKILL; got != want {
+		t.Errorf("ws.Signal() got %v, want %v", got, want)
+	}
+}
+
+// Test that job control signals work on a console created with "run -ti".
+func TestJobControlSignalRootContainer(t *testing.T) {
+	conf := testutil.TestConfig(t)
+	// Don't let bash execute from profile or rc files, otherwise our PID
+	// counts get messed up.
+	spec := testutil.NewSpecWithArgs("/bin/bash", "--noprofile", "--norc")
+	spec.Process.Terminal = true
+
+	_, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf)
+	if err != nil {
+		t.Fatalf("error setting up container: %v", err)
+	}
+	defer cleanup()
+
+	sock, err := socketPath(bundleDir)
+	if err != nil {
+		t.Fatalf("error getting socket path: %v", err)
+	}
+	srv, cleanup := createConsoleSocket(t, sock)
+	defer cleanup()
+
+	// Create the container and pass the socket name.
+	args := Args{
+		ID:            testutil.RandomContainerID(),
+		Spec:          spec,
+		BundleDir:     bundleDir,
+		ConsoleSocket: sock,
+	}
+	c, err := New(conf, args)
+	if err != nil {
+		t.Fatalf("error creating container: %v", err)
+	}
+	defer c.Destroy()
+
+	// Get the PTY master.
+	ptyMaster, err := receiveConsolePTY(srv)
+	if err != nil {
+		t.Fatalf("error receiving console FD: %v", err)
+	}
+	defer ptyMaster.Close()
+
+	// Bash output as well as sandbox output will be written to the PTY
+	// file. Writes after a certain point will block unless we drain the
+	// PTY, so we must continually copy from it.
+	//
+	// We log the output to stderr for debugabilitly, and also to a buffer,
+	// since we wait on particular output from bash below. We use a custom
+	// blockingBuffer which is thread-safe and also blocks on Read calls,
+	// which makes this a suitable Reader for WaitUntilRead.
+	ptyBuf := newBlockingBuffer()
+	tee := io.TeeReader(ptyMaster, ptyBuf)
+	go io.Copy(os.Stderr, tee)
+
+	// Start the container.
+	if err := c.Start(conf); err != nil {
+		t.Fatalf("error starting container: %v", err)
+	}
+
+	// Start waiting for the container to exit in a goroutine. We do this
+	// very early, otherwise it might exit before we have a chance to call
+	// Wait.
+	var (
+		ws syscall.WaitStatus
+		wg sync.WaitGroup
+	)
+	wg.Add(1)
+	go func() {
+		var err error
+		ws, err = c.Wait()
+		if err != nil {
+			t.Errorf("error waiting on container: %v", err)
+		}
+		wg.Done()
+	}()
+
+	// Wait for bash to start.
+	expectedPL := []*control.Process{
+		{PID: 1, Cmd: "bash", Threads: []kernel.ThreadID{1}},
+	}
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Fatalf("error waiting for processes: %v", err)
+	}
+
+	// Execute sleep via the terminal.
+	ptyMaster.Write([]byte("sleep 100\n"))
+
+	// Wait for sleep to start.
+	expectedPL = append(expectedPL, &control.Process{PID: 2, PPID: 1, Cmd: "sleep", Threads: []kernel.ThreadID{2}})
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Fatalf("error waiting for processes: %v", err)
+	}
+
+	// Reset the pty buffer, so there is less output for us to scan later.
+	ptyBuf.Reset()
+
+	// Send a SIGTERM to the foreground process. We pass PID=0, indicating
+	// that the root process should be killed. However, by setting
+	// fgProcess=true, the signal should actually be sent to sleep.
+	if err := c.Sandbox.SignalProcess(c.ID, 0 /* PID */, syscall.SIGTERM, true /* fgProcess */); err != nil {
+		t.Fatalf("error signaling container: %v", err)
+	}
+
+	// Sleep process should be gone.
+	expectedPL = expectedPL[:len(expectedPL)-1]
+	if err := waitForProcessList(c, expectedPL); err != nil {
+		t.Error(err)
+	}
+
+	// Sleep is dead, but it may take more time for bash to notice and
+	// change the foreground process back to itself. We know it is done
+	// when bash writes "Terminated" to the pty.
+	if err := testutil.WaitUntilRead(ptyBuf, "Terminated", nil, 5*time.Second); err != nil {
+		t.Fatalf("bash did not take over pty: %v", err)
+	}
+
+	// Send a SIGKILL to the foreground process again. This time "bash"
+	// should be killed. We use SIGKILL instead of SIGTERM or SIGINT
+	// because bash ignores those.
+	if err := c.Sandbox.SignalProcess(c.ID, 0 /* PID */, syscall.SIGKILL, true /* fgProcess */); err != nil {
+		t.Fatalf("error signaling container: %v", err)
+	}
+
+	// Wait for the sandbox to exit. It should exit with a SIGKILL status.
+	wg.Wait()
+	if !ws.Signaled() {
+		t.Error("ws.Signaled() got false, want true")
+	}
+	if got, want := ws.Signal(), syscall.SIGKILL; got != want {
+		t.Errorf("ws.Signal() got %v, want %v", got, want)
+	}
+}
+
+// blockingBuffer is a thread-safe buffer that blocks when reading if the
+// buffer is empty.  It implements io.ReadWriter.
+type blockingBuffer struct {
+	// A send to readCh indicates that a previously empty buffer now has
+	// data for reading.
+	readCh chan struct{}
+
+	// mu protects buf.
+	mu  sync.Mutex
+	buf bytes.Buffer
+}
+
+func newBlockingBuffer() *blockingBuffer {
+	return &blockingBuffer{
+		readCh: make(chan struct{}, 1),
+	}
+}
+
+// Write implements Writer.Write.
+func (bb *blockingBuffer) Write(p []byte) (int, error) {
+	bb.mu.Lock()
+	defer bb.mu.Unlock()
+	l := bb.buf.Len()
+	n, err := bb.buf.Write(p)
+	if l == 0 && n > 0 {
+		// New data!
+		bb.readCh <- struct{}{}
+	}
+	return n, err
+}
+
+// Read implements Reader.Read. It will block until data is available.
+func (bb *blockingBuffer) Read(p []byte) (int, error) {
+	for {
+		bb.mu.Lock()
+		n, err := bb.buf.Read(p)
+		if n > 0 || err != io.EOF {
+			if bb.buf.Len() == 0 {
+				// Reset the readCh.
+				select {
+				case <-bb.readCh:
+				default:
+				}
+			}
+			bb.mu.Unlock()
+			return n, err
+		}
+		bb.mu.Unlock()
+
+		// Wait for new data.
+		<-bb.readCh
+	}
+}
+
+// Reset resets the buffer.
+func (bb *blockingBuffer) Reset() {
+	bb.mu.Lock()
+	defer bb.mu.Unlock()
+	bb.buf.Reset()
+	// Reset the readCh.
+	select {
+	case <-bb.readCh:
+	default:
+	}
+}