diff options
| -rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 12 | ||||
| -rw-r--r-- | test/packetimpact/tests/BUILD | 2 | ||||
| -rw-r--r-- | test/packetimpact/tests/tcp_queue_receive_in_syn_sent_test.go | 131 |
3 files changed, 98 insertions, 47 deletions
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index 99a691815..bd3ec5a8d 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -1212,6 +1212,16 @@ func (e *endpoint) SetOwner(owner tcpip.PacketOwner) { // Read reads data from the endpoint. func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { e.LockUser() + defer e.UnlockUser() + + // When in SYN-SENT state, let the caller block on the receive. + // An application can initiate a non-blocking connect and then block + // on a receive. It can expect to read any data after the handshake + // is complete. RFC793, section 3.9, p58. + if e.EndpointState() == StateSynSent { + return buffer.View{}, tcpip.ControlMessages{}, tcpip.ErrWouldBlock + } + // The endpoint can be read if it's connected, or if it's already closed // but has some pending unread data. Also note that a RST being received // would cause the state to become StateError so we should allow the @@ -1221,7 +1231,6 @@ func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, if s := e.EndpointState(); !s.connected() && s != StateClose && bufUsed == 0 { e.rcvListMu.Unlock() he := e.HardError - e.UnlockUser() if s == StateError { return buffer.View{}, tcpip.ControlMessages{}, he } @@ -1231,7 +1240,6 @@ func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, v, err := e.readLocked() e.rcvListMu.Unlock() - e.UnlockUser() if err == tcpip.ErrClosedForReceive { e.stats.ReadErrors.ReadClosed.Increment() diff --git a/test/packetimpact/tests/BUILD b/test/packetimpact/tests/BUILD index 4711c1ae6..85749c559 100644 --- a/test/packetimpact/tests/BUILD +++ b/test/packetimpact/tests/BUILD @@ -183,8 +183,6 @@ packetimpact_go_test( packetimpact_go_test( name = "tcp_queue_receive_in_syn_sent", srcs = ["tcp_queue_receive_in_syn_sent_test.go"], - # TODO(b/157658105): Fix netstack then remove the line below. - expect_netstack_failure = True, deps = [ "//pkg/tcpip/header", "//test/packetimpact/testbench", diff --git a/test/packetimpact/tests/tcp_queue_receive_in_syn_sent_test.go b/test/packetimpact/tests/tcp_queue_receive_in_syn_sent_test.go index b640d8673..8fbec893b 100644 --- a/test/packetimpact/tests/tcp_queue_receive_in_syn_sent_test.go +++ b/test/packetimpact/tests/tcp_queue_receive_in_syn_sent_test.go @@ -35,53 +35,98 @@ func init() { testbench.RegisterFlags(flag.CommandLine) } +// TestQueueReceiveInSynSent tests receive behavior when the TCP state +// is SYN-SENT. +// It tests for 2 variants where the receive is blocked and: +// (1) we complete handshake and send sample data. +// (2) we send a TCP RST. func TestQueueReceiveInSynSent(t *testing.T) { - dut := testbench.NewDUT(t) - defer dut.TearDown() + for _, tt := range []struct { + description string + reset bool + }{ + {description: "Send DATA", reset: false}, + {description: "Send RST", reset: true}, + } { + t.Run(tt.description, func(t *testing.T) { + dut := testbench.NewDUT(t) + defer dut.TearDown() - socket, remotePort := dut.CreateBoundSocket(unix.SOCK_STREAM, unix.IPPROTO_TCP, net.ParseIP(testbench.RemoteIPv4)) - conn := testbench.NewTCPIPv4(t, testbench.TCP{DstPort: &remotePort}, testbench.TCP{SrcPort: &remotePort}) - defer conn.Close() + socket, remotePort := dut.CreateBoundSocket(unix.SOCK_STREAM, unix.IPPROTO_TCP, net.ParseIP(testbench.RemoteIPv4)) + conn := testbench.NewTCPIPv4(t, testbench.TCP{DstPort: &remotePort}, testbench.TCP{SrcPort: &remotePort}) + defer conn.Close() - sampleData := []byte("Sample Data") + sampleData := []byte("Sample Data") - dut.SetNonBlocking(socket, true) - if _, err := dut.ConnectWithErrno(context.Background(), socket, conn.LocalAddr()); !errors.Is(err, syscall.EINPROGRESS) { - t.Fatalf("failed to bring DUT to SYN-SENT, got: %s, want EINPROGRESS", err) - } - if _, err := conn.Expect(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagSyn)}, time.Second); err != nil { - t.Fatalf("expected a SYN from DUT, but got none: %s", err) - } + dut.SetNonBlocking(socket, true) + if _, err := dut.ConnectWithErrno(context.Background(), socket, conn.LocalAddr()); !errors.Is(err, syscall.EINPROGRESS) { + t.Fatalf("failed to bring DUT to SYN-SENT, got: %s, want EINPROGRESS", err) + } + if _, err := conn.Expect(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagSyn)}, time.Second); err != nil { + t.Fatalf("expected a SYN from DUT, but got none: %s", err) + } - // Issue RECEIVE call in SYN-SENT, this should be queued for process until the connection - // is established. - dut.SetNonBlocking(socket, false) - var wg sync.WaitGroup - defer wg.Wait() - wg.Add(1) - go func() { - defer wg.Done() - ctx, cancel := context.WithTimeout(context.Background(), time.Second*3) - defer cancel() - n, buff, err := dut.RecvWithErrno(ctx, socket, int32(len(sampleData)), 0) - if n == -1 { - t.Fatalf("failed to recv on DUT: %s", err) - } - if got := buff[:n]; !bytes.Equal(got, sampleData) { - t.Fatalf("received data don't match, got:\n%s, want:\n%s", hex.Dump(got), hex.Dump(sampleData)) - } - }() - - // The following sleep is used to prevent the connection from being established while the - // RPC is in flight. - time.Sleep(time.Second) - - // Bring the connection to Established. - conn.Send(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagSyn | header.TCPFlagAck)}) - if _, err := conn.Expect(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}, time.Second); err != nil { - t.Fatalf("expected an ACK from DUT, but got none: %s", err) - } + if _, _, err := dut.RecvWithErrno(context.Background(), socket, int32(len(sampleData)), 0); err != syscall.Errno(unix.EWOULDBLOCK) { + t.Fatalf("expected error %s, got %s", syscall.Errno(unix.EWOULDBLOCK), err) + } + + // Test blocking read. + dut.SetNonBlocking(socket, false) + + var wg sync.WaitGroup + defer wg.Wait() + wg.Add(1) + var block sync.WaitGroup + block.Add(1) + go func() { + defer wg.Done() + ctx, cancel := context.WithTimeout(context.Background(), time.Second*3) + defer cancel() - // Send sample data to DUT. - conn.Send(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}, &testbench.Payload{Bytes: sampleData}) + block.Done() + // Issue RECEIVE call in SYN-SENT, this should be queued for + // process until the connection is established. + n, buff, err := dut.RecvWithErrno(ctx, socket, int32(len(sampleData)), 0) + if tt.reset { + if err != syscall.Errno(unix.ECONNREFUSED) { + t.Errorf("expected error %s, got %s", syscall.Errno(unix.ECONNREFUSED), err) + } + if n != -1 { + t.Errorf("expected return value %d, got %d", -1, n) + } + return + } + if n == -1 { + t.Errorf("failed to recv on DUT: %s", err) + } + if got := buff[:n]; !bytes.Equal(got, sampleData) { + t.Errorf("received data doesn't match, got:\n%s, want:\n%s", hex.Dump(got), hex.Dump(sampleData)) + } + }() + + // Wait for the goroutine to be scheduled and before it + // blocks on endpoint receive. + block.Wait() + // The following sleep is used to prevent the connection + // from being established before we are blocked on Recv. + time.Sleep(100 * time.Millisecond) + + if tt.reset { + conn.Send(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagRst | header.TCPFlagAck)}) + return + } + + // Bring the connection to Established. + conn.Send(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagSyn | header.TCPFlagAck)}) + if _, err := conn.Expect(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}, time.Second); err != nil { + t.Fatalf("expected an ACK from DUT, but got none: %s", err) + } + + // Send sample payload and expect an ACK. + conn.Send(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}, &testbench.Payload{Bytes: sampleData}) + if _, err := conn.Expect(testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}, time.Second); err != nil { + t.Fatalf("expected an ACK from DUT, but got none: %s", err) + } + }) + } } |