diff options
| -rw-r--r-- | test/packetimpact/testbench/connections.go | 20 | ||||
| -rw-r--r-- | test/packetimpact/tests/BUILD | 13 | ||||
| -rw-r--r-- | test/packetimpact/tests/tcp_outside_the_window_test.go | 88 |
3 files changed, 118 insertions, 3 deletions
diff --git a/test/packetimpact/testbench/connections.go b/test/packetimpact/testbench/connections.go index 169db01b0..be62d051d 100644 --- a/test/packetimpact/testbench/connections.go +++ b/test/packetimpact/testbench/connections.go @@ -577,13 +577,27 @@ func (conn *TCPIPv4) Expect(tcp TCP, timeout time.Duration) (*TCP, error) { return gotTCP, err } -// RemoteSeqNum returns the next expected sequence number from the DUT. -func (conn *TCPIPv4) RemoteSeqNum() *seqnum.Value { +func (conn *TCPIPv4) state() *tcpState { state, ok := conn.layerStates[len(conn.layerStates)-1].(*tcpState) if !ok { conn.t.Fatalf("expected final state of %v to be tcpState", conn.layerStates) } - return state.remoteSeqNum + return state +} + +// RemoteSeqNum returns the next expected sequence number from the DUT. +func (conn *TCPIPv4) RemoteSeqNum() *seqnum.Value { + return conn.state().remoteSeqNum +} + +// LocalSeqNum returns the next expected sequence number from the DUT. +func (conn *TCPIPv4) LocalSeqNum() *seqnum.Value { + return conn.state().localSeqNum +} + +// SynAck returns the SynAck that was part of the handshake. +func (conn *TCPIPv4) SynAck() *TCP { + return conn.state().synAck } // Drain drains the sniffer's receive buffer by receiving packets until there's diff --git a/test/packetimpact/tests/BUILD b/test/packetimpact/tests/BUILD index 1274d9f60..4f8c8bdc0 100644 --- a/test/packetimpact/tests/BUILD +++ b/test/packetimpact/tests/BUILD @@ -41,6 +41,19 @@ packetimpact_go_test( ) packetimpact_go_test( + name = "tcp_outside_the_window", + srcs = ["tcp_outside_the_window_test.go"], + # TODO(eyalsoha): Fix #1607 then remove the line below. + netstack = False, + deps = [ + "//pkg/tcpip/header", + "//pkg/tcpip/seqnum", + "//test/packetimpact/testbench", + "@org_golang_x_sys//unix:go_default_library", + ], +) + +packetimpact_go_test( name = "tcp_noaccept_close_rst", srcs = ["tcp_noaccept_close_rst_test.go"], deps = [ diff --git a/test/packetimpact/tests/tcp_outside_the_window_test.go b/test/packetimpact/tests/tcp_outside_the_window_test.go new file mode 100644 index 000000000..db3d3273b --- /dev/null +++ b/test/packetimpact/tests/tcp_outside_the_window_test.go @@ -0,0 +1,88 @@ +// Copyright 2020 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 tcp_outside_the_window_test + +import ( + "fmt" + "testing" + "time" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/tcpip/header" + "gvisor.dev/gvisor/pkg/tcpip/seqnum" + tb "gvisor.dev/gvisor/test/packetimpact/testbench" +) + +// TestTCPOutsideTheWindows tests the behavior of the DUT when packets arrive +// that are inside or outside the TCP window. Packets that are outside the +// window should force an extra ACK, as described in RFC793 page 69: +// https://tools.ietf.org/html/rfc793#page-69 +func TestTCPOutsideTheWindow(t *testing.T) { + for _, tt := range []struct { + description string + tcpFlags uint8 + payload []tb.Layer + seqNumOffset seqnum.Size + expectACK bool + }{ + {"SYN", header.TCPFlagSyn, nil, 0, true}, + {"SYNACK", header.TCPFlagSyn | header.TCPFlagAck, nil, 0, true}, + {"ACK", header.TCPFlagAck, nil, 0, false}, + {"FIN", header.TCPFlagFin, nil, 0, false}, + {"Data", header.TCPFlagAck, []tb.Layer{&tb.Payload{Bytes: []byte("abc123")}}, 0, true}, + + {"SYN", header.TCPFlagSyn, nil, 1, true}, + {"SYNACK", header.TCPFlagSyn | header.TCPFlagAck, nil, 1, true}, + {"ACK", header.TCPFlagAck, nil, 1, true}, + {"FIN", header.TCPFlagFin, nil, 1, false}, + {"Data", header.TCPFlagAck, []tb.Layer{&tb.Payload{Bytes: []byte("abc123")}}, 1, true}, + + {"SYN", header.TCPFlagSyn, nil, 2, true}, + {"SYNACK", header.TCPFlagSyn | header.TCPFlagAck, nil, 2, true}, + {"ACK", header.TCPFlagAck, nil, 2, true}, + {"FIN", header.TCPFlagFin, nil, 2, false}, + {"Data", header.TCPFlagAck, []tb.Layer{&tb.Payload{Bytes: []byte("abc123")}}, 2, true}, + } { + t.Run(fmt.Sprintf("%s%d", tt.description, tt.seqNumOffset), func(t *testing.T) { + dut := tb.NewDUT(t) + defer dut.TearDown() + listenFD, remotePort := dut.CreateListener(unix.SOCK_STREAM, unix.IPPROTO_TCP, 1) + defer dut.Close(listenFD) + conn := tb.NewTCPIPv4(t, tb.TCP{DstPort: &remotePort}, tb.TCP{SrcPort: &remotePort}) + defer conn.Close() + conn.Handshake() + acceptFD, _ := dut.Accept(listenFD) + defer dut.Close(acceptFD) + + windowSize := seqnum.Size(*conn.SynAck().WindowSize) + tt.seqNumOffset + conn.Drain() + // Ignore whatever incrementing that this out-of-order packet might cause + // to the AckNum. + localSeqNum := tb.Uint32(uint32(*conn.LocalSeqNum())) + conn.Send(tb.TCP{ + Flags: tb.Uint8(tt.tcpFlags), + SeqNum: tb.Uint32(uint32(conn.LocalSeqNum().Add(windowSize))), + }, tt.payload...) + timeout := 3 * time.Second + gotACK, err := conn.Expect(tb.TCP{Flags: tb.Uint8(header.TCPFlagAck), AckNum: localSeqNum}, timeout) + if tt.expectACK && err != nil { + t.Fatalf("expected an ACK packet within %s but got none: %s", timeout, err) + } + if !tt.expectACK && gotACK != nil { + t.Fatalf("expected no ACK packet within %s but got one: %s", timeout, gotACK) + } + }) + } +} |