diff options
| -rw-r--r-- | pkg/tcpip/transport/tcp/rcv.go | 7 | ||||
| -rw-r--r-- | test/packetimpact/tests/BUILD | 12 | ||||
| -rw-r--r-- | test/packetimpact/tests/tcp_timewait_reset_test.go | 68 |
3 files changed, 87 insertions, 0 deletions
diff --git a/pkg/tcpip/transport/tcp/rcv.go b/pkg/tcpip/transport/tcp/rcv.go index bc920a03b..cfd43b5e3 100644 --- a/pkg/tcpip/transport/tcp/rcv.go +++ b/pkg/tcpip/transport/tcp/rcv.go @@ -436,6 +436,13 @@ func (r *receiver) handleTimeWaitSegment(s *segment) (resetTimeWait bool, newSyn // Just silently drop any RST packets in TIME_WAIT. We do not support // TIME_WAIT assasination as a result we confirm w/ fix 1 as described // in https://tools.ietf.org/html/rfc1337#section-3. + // + // This behavior overrides RFC793 page 70 where we transition to CLOSED + // on receiving RST, which is also default Linux behavior. + // On Linux the RST can be ignored by setting sysctl net.ipv4.tcp_rfc1337. + // + // As we do not yet support PAWS, we are being conservative in ignoring + // RSTs by default. if s.flagIsSet(header.TCPFlagRst) { return false, false } diff --git a/test/packetimpact/tests/BUILD b/test/packetimpact/tests/BUILD index e1ed0cc60..6dda05102 100644 --- a/test/packetimpact/tests/BUILD +++ b/test/packetimpact/tests/BUILD @@ -260,6 +260,18 @@ packetimpact_go_test( ) packetimpact_go_test( + name = "tcp_timewait_reset", + srcs = ["tcp_timewait_reset_test.go"], + # TODO(b/168523247): Fix netstack then remove the line below. + expect_netstack_failure = True, + deps = [ + "//pkg/tcpip/header", + "//test/packetimpact/testbench", + "@org_golang_x_sys//unix:go_default_library", + ], +) + +packetimpact_go_test( name = "icmpv6_param_problem", srcs = ["icmpv6_param_problem_test.go"], # TODO(b/153485026): Fix netstack then remove the line below. diff --git a/test/packetimpact/tests/tcp_timewait_reset_test.go b/test/packetimpact/tests/tcp_timewait_reset_test.go new file mode 100644 index 000000000..2f76a6531 --- /dev/null +++ b/test/packetimpact/tests/tcp_timewait_reset_test.go @@ -0,0 +1,68 @@ +// 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_timewait_reset_test + +import ( + "flag" + "testing" + "time" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/tcpip/header" + "gvisor.dev/gvisor/test/packetimpact/testbench" +) + +func init() { + testbench.RegisterFlags(flag.CommandLine) +} + +// TestTimeWaitReset tests handling of RST when in TIME_WAIT state. +func TestTimeWaitReset(t *testing.T) { + dut := testbench.NewDUT(t) + defer dut.TearDown() + listenFD, remotePort := dut.CreateListener(t, unix.SOCK_STREAM, unix.IPPROTO_TCP, 1 /*backlog*/) + defer dut.Close(t, listenFD) + conn := testbench.NewTCPIPv4(t, testbench.TCP{DstPort: &remotePort}, testbench.TCP{SrcPort: &remotePort}) + defer conn.Close(t) + + conn.Connect(t) + acceptFD, _ := dut.Accept(t, listenFD) + + // Trigger active close. + dut.Close(t, acceptFD) + + _, err := conn.Expect(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagFin | header.TCPFlagAck)}, time.Second) + if err != nil { + t.Fatalf("expected a FIN: %s", err) + } + conn.Send(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}) + // Send a FIN, DUT should transition to TIME_WAIT from FIN_WAIT2. + conn.Send(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagFin | header.TCPFlagAck)}) + if _, err := conn.Expect(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}, time.Second); err != nil { + t.Fatalf("expected an ACK for our FIN: %s", err) + } + + // Send a RST, the DUT should transition to CLOSED from TIME_WAIT. + // This is the default Linux behavior, it can be changed to ignore RSTs via + // sysctl net.ipv4.tcp_rfc1337. + conn.Send(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagRst)}) + + conn.Send(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck)}) + // The DUT should reply with RST to our ACK as the state should have + // transitioned to CLOSED. + if _, err := conn.Expect(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagRst)}, time.Second); err != nil { + t.Fatalf("expected a RST: %s", err) + } +} |