diff options
Diffstat (limited to 'test/packetimpact')
| -rw-r--r-- | test/packetimpact/tests/tcp_rack_test.go | 37 |
1 files changed, 16 insertions, 21 deletions
diff --git a/test/packetimpact/tests/tcp_rack_test.go b/test/packetimpact/tests/tcp_rack_test.go index fb2a4cc90..ef902c54d 100644 --- a/test/packetimpact/tests/tcp_rack_test.go +++ b/test/packetimpact/tests/tcp_rack_test.go @@ -168,9 +168,10 @@ func TestRACKTLPLost(t *testing.T) { closeSACKConnection(t, dut, conn, acceptFd, listenFd) } -// TestRACKTLPWithSACK tests TLP by acknowledging out of order packets. +// TestRACKWithSACK tests that RACK marks the packets as lost after receiving +// the ACK for retransmitted packets. // See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-8.1 -func TestRACKTLPWithSACK(t *testing.T) { +func TestRACKWithSACK(t *testing.T) { dut, conn, acceptFd, listenFd := createSACKConnection(t) seqNum1 := *conn.RemoteSeqNum(t) @@ -180,8 +181,9 @@ func TestRACKTLPWithSACK(t *testing.T) { // We are not sending ACK for these packets. const numPkts = 3 - lastSent := sendAndReceive(t, dut, conn, numPkts, acceptFd, false /* sendACK */) + sendAndReceive(t, dut, conn, numPkts, acceptFd, false /* sendACK */) + time.Sleep(simulatedRTT) // SACK for #2 packet. sackBlock := make([]byte, 40) start := seqNum1.Add(seqnum.Size(payloadSize)) @@ -194,32 +196,25 @@ func TestRACKTLPWithSACK(t *testing.T) { }}, sackBlock[sbOff:]) conn.Send(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck), AckNum: testbench.Uint32(uint32(seqNum1)), Options: sackBlock[:sbOff]}) - // RACK marks #1 packet as lost and retransmits it. - if _, err := conn.Expect(t, testbench.TCP{SeqNum: testbench.Uint32(uint32(seqNum1))}, time.Second); err != nil { + rtt, _ := getRTTAndRTO(t, dut, acceptFd) + timeout := 2 * rtt + // RACK marks #1 packet as lost after RTT+reorderWindow(RTT/4) and + // retransmits it. + if _, err := conn.Expect(t, testbench.TCP{SeqNum: testbench.Uint32(uint32(seqNum1))}, timeout); err != nil { t.Fatalf("expected payload was not received: %s", err) } + time.Sleep(simulatedRTT) // ACK for #1 packet. conn.Send(t, testbench.TCP{Flags: testbench.Uint8(header.TCPFlagAck), AckNum: testbench.Uint32(uint32(end))}) - // Probe Timeout (PTO) should be two times RTT. TLP will trigger for #3 - // packet. RACK adds an additional timeout of 200ms if the number of - // outstanding packets is equal to 1. - rtt, rto := getRTTAndRTO(t, dut, acceptFd) - pto := rtt*2 + (200 * time.Millisecond) - if rto < pto { - pto = rto - } - // We expect the 3rd packet (the last unacknowledged packet) to be - // retransmitted. - tlpProbe := testbench.Uint32(uint32(seqNum1) + uint32((numPkts-1)*payloadSize)) - if _, err := conn.Expect(t, testbench.TCP{SeqNum: tlpProbe}, time.Second); err != nil { + // RACK considers transmission times of the packets to mark them lost. + // As the 3rd packet was sent before the retransmitted 1st packet, RACK + // marks it as lost and retransmits it.. + expectedSeqNum := testbench.Uint32(uint32(seqNum1) + uint32((numPkts-1)*payloadSize)) + if _, err := conn.Expect(t, testbench.TCP{SeqNum: expectedSeqNum}, timeout); err != nil { t.Fatalf("expected payload was not received: %s", err) } - diff := time.Now().Sub(lastSent) - if diff < pto { - t.Fatalf("expected payload was received before the probe timeout, got: %v, want: %v", diff, pto) - } closeSACKConnection(t, dut, conn, acceptFd, listenFd) } |