Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 693 insertions, 0 deletions

diff --git a/pkg/unet/unet_test.go b/pkg/unet/unet_test.go
new file mode 100644
index 000000000..6c546825f
--- /dev/null
+++ b/pkg/unet/unet_test.go
@@ -0,0 +1,693 @@
+// Copyright 2018 Google Inc.
+//
+// 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 unet
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"sync"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func randomFilename() (string, error) {
+	// Return a randomly generated file in the test dir.
+	f, err := ioutil.TempFile("", "unet-test")
+	if err != nil {
+		return "", err
+	}
+	file := f.Name()
+	os.Remove(file)
+	f.Close()
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+
+	// NOTE: We try to use relative path if possible. This is
+	// to help conforming to the unix path length limit.
+	if rel, err := filepath.Rel(cwd, file); err == nil {
+		return rel, nil
+	}
+
+	return file, nil
+}
+
+func TestConnectFailure(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	if _, err := Connect(name, false); err == nil {
+		t.Fatalf("connect was successful, expected err")
+	}
+}
+
+func TestBindFailure(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	ss, err := BindAndListen(name, false)
+	if err != nil {
+		t.Fatalf("first bind failed, got err %v expected nil", err)
+	}
+	defer ss.Close()
+
+	if _, err = BindAndListen(name, false); err == nil {
+		t.Fatalf("second bind succeeded, expected non-nil err")
+	}
+}
+
+func TestMultipleAccept(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	ss, err := BindAndListen(name, false)
+	if err != nil {
+		t.Fatalf("first bind failed, got err %v expected nil", err)
+	}
+	defer ss.Close()
+
+	// Connect backlog times asynchronously.
+	var wg sync.WaitGroup
+	defer wg.Wait()
+	for i := 0; i < backlog; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			s, err := Connect(name, false)
+			if err != nil {
+				t.Fatalf("connect failed, got err %v expected nil", err)
+			}
+			s.Close()
+		}()
+	}
+
+	// Accept backlog times.
+	for i := 0; i < backlog; i++ {
+		s, err := ss.Accept()
+		if err != nil {
+			t.Errorf("accept failed, got err %v expected nil", err)
+			continue
+		}
+		s.Close()
+	}
+}
+
+func TestServerClose(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	ss, err := BindAndListen(name, false)
+	if err != nil {
+		t.Fatalf("first bind failed, got err %v expected nil", err)
+	}
+
+	// Make sure the first close succeeds.
+	if err := ss.Close(); err != nil {
+		t.Fatalf("first close failed, got err %v expected nil", err)
+	}
+
+	// The second one should fail.
+	if err := ss.Close(); err == nil {
+		t.Fatalf("second close succeeded, expected non-nil err")
+	}
+}
+
+func socketPair(t *testing.T, packet bool) (*Socket, *Socket) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	// Bind a server.
+	ss, err := BindAndListen(name, packet)
+	if err != nil {
+		t.Fatalf("error binding, got %v expected nil", err)
+	}
+	defer ss.Close()
+
+	// Accept a client.
+	acceptSocket := make(chan *Socket)
+	acceptErr := make(chan error)
+	go func() {
+		server, err := ss.Accept()
+		if err != nil {
+			acceptErr <- err
+		}
+		acceptSocket <- server
+	}()
+
+	// Connect the client.
+	client, err := Connect(name, packet)
+	if err != nil {
+		t.Fatalf("error connecting, got %v expected nil", err)
+	}
+
+	// Grab the server handle.
+	select {
+	case server := <-acceptSocket:
+		return server, client
+	case err := <-acceptErr:
+		t.Fatalf("accept error: %v", err)
+	}
+	panic("unreachable")
+}
+
+func TestSendRecv(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Write on the client.
+	w := client.Writer(true)
+	if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+		t.Fatalf("for client write, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Read on the server.
+	b := [][]byte{{'b'}}
+	r := server.Reader(true)
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("for server read, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+	if b[0][0] != 'a' {
+		t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+	}
+}
+
+// TestSymmetric exists to assert that the two sockets received from socketPair
+// are interchangeable. They should be, this just provides a basic sanity check
+// by running TestSendRecv "backwards".
+func TestSymmetric(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Write on the server.
+	w := server.Writer(true)
+	if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+		t.Fatalf("for server write, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Read on the client.
+	b := [][]byte{{'b'}}
+	r := client.Reader(true)
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("for client read, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+	if b[0][0] != 'a' {
+		t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+	}
+}
+
+func TestPacket(t *testing.T) {
+	server, client := socketPair(t, true)
+	defer server.Close()
+	defer client.Close()
+
+	// Write on the client.
+	w := client.Writer(true)
+	if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+		t.Fatalf("for client write, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Write on the client again.
+	w = client.Writer(true)
+	if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+		t.Fatalf("for client write, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Read on the server.
+	//
+	// This should only get back a single byte, despite the buffer
+	// being size two. This is because it's a _packet_ buffer.
+	b := [][]byte{{'b', 'b'}}
+	r := server.Reader(true)
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("for server read, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+	if b[0][0] != 'a' {
+		t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+	}
+
+	// Do it again.
+	r = server.Reader(true)
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("for server read, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+	if b[0][0] != 'a' {
+		t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+	}
+}
+
+func TestClose(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+
+	// Make sure the first close succeeds.
+	if err := client.Close(); err != nil {
+		t.Fatalf("first close failed, got err %v expected nil", err)
+	}
+
+	// The second one should fail.
+	if err := client.Close(); err == nil {
+		t.Fatalf("second close succeeded, expected non-nil err")
+	}
+}
+
+func TestNonBlockingSend(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Try up to 1000 writes, of 1000 bytes.
+	blockCount := 0
+	for i := 0; i < 1000; i++ {
+		w := client.Writer(false)
+		if n, err := w.WriteVec([][]byte{make([]byte, 1000)}); n != 1000 || err != nil {
+			if err == syscall.EWOULDBLOCK || err == syscall.EAGAIN {
+				// We're good. That's what we wanted.
+				blockCount++
+			} else {
+				t.Fatalf("for client write, got n=%d err=%v, expected n=1000 err=nil", n, err)
+			}
+		}
+	}
+
+	if blockCount == 1000 {
+		// Shouldn't have _always_ blocked.
+		t.Fatalf("socket always blocked!")
+	} else if blockCount == 0 {
+		// Should have started blocking eventually.
+		t.Fatalf("socket never blocked!")
+	}
+}
+
+func TestNonBlockingRecv(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	b := [][]byte{{'b'}}
+	r := client.Reader(false)
+
+	// Expected to block immediately.
+	_, err := r.ReadVec(b)
+	if err != syscall.EWOULDBLOCK && err != syscall.EAGAIN {
+		t.Fatalf("read didn't block, got err %v expected blocking err", err)
+	}
+
+	// Put some data in the pipe.
+	w := server.Writer(false)
+	if n, err := w.WriteVec(b); n != 1 || err != nil {
+		t.Fatalf("write failed with n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Expect it not to block.
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("read failed with n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Expect it to return a block error again.
+	r = client.Reader(false)
+	_, err = r.ReadVec(b)
+	if err != syscall.EWOULDBLOCK && err != syscall.EAGAIN {
+		t.Fatalf("read didn't block, got err %v expected blocking err", err)
+	}
+}
+
+func TestRecvVectors(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Write on the client.
+	w := client.Writer(true)
+	if n, err := w.WriteVec([][]byte{{'a', 'b'}}); n != 2 || err != nil {
+		t.Fatalf("for client write, got n=%d err=%v, expected n=2 err=nil", n, err)
+	}
+
+	// Read on the server.
+	b := [][]byte{{'c'}, {'c'}}
+	r := server.Reader(true)
+	if n, err := r.ReadVec(b); n != 2 || err != nil {
+		t.Fatalf("for server read, got n=%d err=%v, expected n=2 err=nil", n, err)
+	}
+	if b[0][0] != 'a' || b[1][0] != 'b' {
+		t.Fatalf("got bad read data, got %c,%c, expected a,b", b[0][0], b[1][0])
+	}
+}
+
+func TestSendVectors(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Write on the client.
+	w := client.Writer(true)
+	if n, err := w.WriteVec([][]byte{{'a'}, {'b'}}); n != 2 || err != nil {
+		t.Fatalf("for client write, got n=%d err=%v, expected n=2 err=nil", n, err)
+	}
+
+	// Read on the server.
+	b := [][]byte{{'c', 'c'}}
+	r := server.Reader(true)
+	if n, err := r.ReadVec(b); n != 2 || err != nil {
+		t.Fatalf("for server read, got n=%d err=%v, expected n=2 err=nil", n, err)
+	}
+	if b[0][0] != 'a' || b[0][1] != 'b' {
+		t.Fatalf("got bad read data, got %c,%c, expected a,b", b[0][0], b[0][1])
+	}
+}
+
+func TestSendFDsNotEnabled(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Write on the server.
+	w := server.Writer(true)
+	w.PackFDs(0, 1, 2)
+	if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+		t.Fatalf("for server write, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+
+	// Read on the client, without enabling FDs.
+	b := [][]byte{{'b'}}
+	r := client.Reader(true)
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("for client read, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+	if b[0][0] != 'a' {
+		t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+	}
+
+	// Make sure the FDs are not received.
+	fds, err := r.ExtractFDs()
+	if len(fds) != 0 || err != nil {
+		t.Fatalf("got fds=%v err=%v, expected len(fds)=0 err=nil", fds, err)
+	}
+}
+
+func sendFDs(t *testing.T, s *Socket, fds []int) {
+	w := s.Writer(true)
+	w.PackFDs(fds...)
+	if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+		t.Fatalf("for write, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+}
+
+func recvFDs(t *testing.T, s *Socket, enableSize int, origFDs []int) {
+	expected := len(origFDs)
+
+	// Count the number of FDs.
+	preEntries, err := ioutil.ReadDir("/proc/self/fd")
+	if err != nil {
+		t.Fatalf("can't readdir, got err %v expected nil", err)
+	}
+
+	// Read on the client.
+	b := [][]byte{{'b'}}
+	r := s.Reader(true)
+	if enableSize >= 0 {
+		r.EnableFDs(enableSize)
+	}
+	if n, err := r.ReadVec(b); n != 1 || err != nil {
+		t.Fatalf("for client read, got n=%d err=%v, expected n=1 err=nil", n, err)
+	}
+	if b[0][0] != 'a' {
+		t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+	}
+
+	// Count the new number of FDs.
+	postEntries, err := ioutil.ReadDir("/proc/self/fd")
+	if err != nil {
+		t.Fatalf("can't readdir, got err %v expected nil", err)
+	}
+	if len(preEntries)+expected != len(postEntries) {
+		t.Errorf("process fd count isn't right, expected %d got %d", len(preEntries)+expected, len(postEntries))
+	}
+
+	// Make sure the FDs are there.
+	fds, err := r.ExtractFDs()
+	if len(fds) != expected || err != nil {
+		t.Fatalf("got fds=%v err=%v, expected len(fds)=%d err=nil", fds, err, expected)
+	}
+
+	// Make sure they are different from the originals.
+	for i := 0; i < len(fds); i++ {
+		if fds[i] == origFDs[i] {
+			t.Errorf("got original fd for index %d, expected different", i)
+		}
+	}
+
+	// Make sure they can be accessed as expected.
+	for i := 0; i < len(fds); i++ {
+		var st syscall.Stat_t
+		if err := syscall.Fstat(fds[i], &st); err != nil {
+			t.Errorf("fds[%d] can't be stated, got err %v expected nil", i, err)
+		}
+	}
+
+	// Close them off.
+	r.CloseFDs()
+
+	// Make sure the count is back to normal.
+	finalEntries, err := ioutil.ReadDir("/proc/self/fd")
+	if err != nil {
+		t.Fatalf("can't readdir, got err %v expected nil", err)
+	}
+	if len(finalEntries) != len(preEntries) {
+		t.Errorf("process fd count isn't right, expected %d got %d", len(preEntries), len(finalEntries))
+	}
+}
+
+func TestFDsSingle(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	sendFDs(t, server, []int{0})
+	recvFDs(t, client, 1, []int{0})
+}
+
+func TestFDsMultiple(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	// Basic case, multiple FDs.
+	sendFDs(t, server, []int{0, 1, 2})
+	recvFDs(t, client, 3, []int{0, 1, 2})
+}
+
+// See TestSymmetric above.
+func TestFDsSymmetric(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	sendFDs(t, server, []int{0, 1, 2})
+	recvFDs(t, client, 3, []int{0, 1, 2})
+}
+
+func TestFDsReceiveLargeBuffer(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	sendFDs(t, server, []int{0})
+	recvFDs(t, client, 3, []int{0})
+}
+
+func TestFDsReceiveSmallBuffer(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	sendFDs(t, server, []int{0, 1, 2})
+
+	// Per the spec, we may still receive more than the buffer. In fact,
+	// it'll be rounded up and we can receive two with a size one buffer.
+	recvFDs(t, client, 1, []int{0, 1})
+}
+
+func TestFDsReceiveNotEnabled(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	sendFDs(t, server, []int{0})
+	recvFDs(t, client, -1, []int{})
+}
+
+func TestFDsReceiveSizeZero(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	sendFDs(t, server, []int{0})
+	recvFDs(t, client, 0, []int{})
+}
+
+func TestGetPeerCred(t *testing.T) {
+	server, client := socketPair(t, false)
+	defer server.Close()
+	defer client.Close()
+
+	want := &syscall.Ucred{
+		Pid: int32(os.Getpid()),
+		Uid: uint32(os.Getuid()),
+		Gid: uint32(os.Getgid()),
+	}
+
+	if got, err := client.GetPeerCred(); err != nil || !reflect.DeepEqual(got, want) {
+		t.Errorf("got GetPeerCred() = %v, %v, want = %+v, %+v", got, err, want, nil)
+	}
+}
+
+func newClosedSocket() (*Socket, error) {
+	fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_STREAM, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	s, err := NewSocket(fd)
+	if err != nil {
+		syscall.Close(fd)
+		return nil, err
+	}
+
+	return s, s.Close()
+}
+
+func TestGetPeerCredFailure(t *testing.T) {
+	s, err := newClosedSocket()
+	if err != nil {
+		t.Fatalf("newClosedSocket got error %v want nil", err)
+	}
+
+	want := "bad file descriptor"
+	if _, err := s.GetPeerCred(); err == nil || err.Error() != want {
+		t.Errorf("got s.GetPeerCred() = %v, want = %s", err, want)
+	}
+}
+
+func TestAcceptClosed(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	ss, err := BindAndListen(name, false)
+	if err != nil {
+		t.Fatalf("bind failed, got err %v expected nil", err)
+	}
+
+	if err := ss.Close(); err != nil {
+		t.Fatalf("close failed, got err %v expected nil", err)
+	}
+
+	if _, err := ss.Accept(); err == nil {
+		t.Errorf("accept on closed SocketServer, got err %v, want != nil", err)
+	}
+}
+
+func TestCloseAfterAcceptStart(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	ss, err := BindAndListen(name, false)
+	if err != nil {
+		t.Fatalf("bind failed, got err %v expected nil", err)
+	}
+
+	wg := sync.WaitGroup{}
+	wg.Add(1)
+	go func() {
+		time.Sleep(50 * time.Millisecond)
+		if err := ss.Close(); err != nil {
+			t.Fatalf("close failed, got err %v expected nil", err)
+		}
+		wg.Done()
+	}()
+
+	if _, err := ss.Accept(); err == nil {
+		t.Errorf("accept on closed SocketServer, got err %v, want != nil", err)
+	}
+
+	wg.Wait()
+}
+
+func TestReleaseAfterAcceptStart(t *testing.T) {
+	name, err := randomFilename()
+	if err != nil {
+		t.Fatalf("unable to generate file, got err %v expected nil", err)
+	}
+
+	ss, err := BindAndListen(name, false)
+	if err != nil {
+		t.Fatalf("bind failed, got err %v expected nil", err)
+	}
+
+	wg := sync.WaitGroup{}
+	wg.Add(1)
+	go func() {
+		time.Sleep(50 * time.Millisecond)
+		fd, err := ss.Release()
+		if err != nil {
+			t.Fatalf("Release failed, got err %v expected nil", err)
+		}
+		syscall.Close(fd)
+		wg.Done()
+	}()
+
+	if _, err := ss.Accept(); err == nil {
+		t.Errorf("accept on closed SocketServer, got err %v, want != nil", err)
+	}
+
+	wg.Wait()
+}
+
+func TestControlMessage(t *testing.T) {
+	for i := 0; i <= 10; i++ {
+		var want []int
+		for j := 0; j < i; j++ {
+			want = append(want, i+j+1)
+		}
+
+		var cm ControlMessage
+		cm.EnableFDs(i)
+		cm.PackFDs(want...)
+		got, err := cm.ExtractFDs()
+		if err != nil || !reflect.DeepEqual(got, want) {
+			t.Errorf("got cm.ExtractFDs() = %v, %v, want = %v, %v", got, err, want, nil)
+		}
+	}
+}