summaryrefslogtreecommitdiffhomepage
diff options
context:
space:
mode:
Diffstat
-rw-r--r--pkg/tcpip/stack/stack.go13
-rw-r--r--pkg/tcpip/transport/tcp/BUILD3
-rw-r--r--pkg/tcpip/transport/tcp/accept.go2
-rw-r--r--pkg/tcpip/transport/tcp/connect.go13
-rw-r--r--pkg/tcpip/transport/tcp/endpoint.go15
-rw-r--r--pkg/tcpip/transport/tcp/rack.go82
-rw-r--r--pkg/tcpip/transport/tcp/rack_state.go29
-rw-r--r--pkg/tcpip/transport/tcp/snd.go40
-rw-r--r--pkg/tcpip/transport/tcp/tcp_rack_test.go74
9 files changed, 248 insertions, 23 deletions
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 3f07e4159..7189e8e7e 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -73,6 +73,16 @@ type TCPCubicState struct {
WEst float64
}
+// TCPRACKState is used to hold a copy of the internal RACK state when the
+// TCPProbeFunc is invoked.
+type TCPRACKState struct {
+ XmitTime time.Time
+ EndSequence seqnum.Value
+ FACK seqnum.Value
+ RTT time.Duration
+ Reord bool
+}
+
// TCPEndpointID is the unique 4 tuple that identifies a given endpoint.
type TCPEndpointID struct {
// LocalPort is the local port associated with the endpoint.
@@ -212,6 +222,9 @@ type TCPSenderState struct {
// Cubic holds the state related to CUBIC congestion control.
Cubic TCPCubicState
+
+ // RACKState holds the state related to RACK loss detection algorithm.
+ RACKState TCPRACKState
}
// TCPSACKInfo holds TCP SACK related information for a given TCP endpoint.
diff --git a/pkg/tcpip/transport/tcp/BUILD b/pkg/tcpip/transport/tcp/BUILD
index e860ee484..234fb95ce 100644
--- a/pkg/tcpip/transport/tcp/BUILD
+++ b/pkg/tcpip/transport/tcp/BUILD
@@ -40,6 +40,8 @@ go_library(
"endpoint_state.go",
"forwarder.go",
"protocol.go",
+ "rack.go",
+ "rack_state.go",
"rcv.go",
"rcv_state.go",
"reno.go",
@@ -83,6 +85,7 @@ go_test(
"dual_stack_test.go",
"sack_scoreboard_test.go",
"tcp_noracedetector_test.go",
+ "tcp_rack_test.go",
"tcp_sack_test.go",
"tcp_test.go",
"tcp_timestamp_test.go",
diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go
index 6e00e5526..913ea6535 100644
--- a/pkg/tcpip/transport/tcp/accept.go
+++ b/pkg/tcpip/transport/tcp/accept.go
@@ -521,7 +521,7 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) {
synOpts := header.TCPSynOptions{
WS: -1,
TS: opts.TS,
- TSVal: tcpTimeStamp(timeStampOffset()),
+ TSVal: tcpTimeStamp(time.Now(), timeStampOffset()),
TSEcr: opts.TSVal,
MSS: mssForRoute(&s.route),
}
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 6e5e55b6f..8dd759ba2 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -1166,13 +1166,18 @@ func (e *endpoint) handleSegments(fastPath bool) *tcpip.Error {
return nil
}
-// handleSegment handles a given segment and notifies the worker goroutine if
-// if the connection should be terminated.
-func (e *endpoint) handleSegment(s *segment) (cont bool, err *tcpip.Error) {
- // Invoke the tcp probe if installed.
+func (e *endpoint) probeSegment() {
if e.probe != nil {
e.probe(e.completeState())
}
+}
+
+// handleSegment handles a given segment and notifies the worker goroutine if
+// if the connection should be terminated.
+func (e *endpoint) handleSegment(s *segment) (cont bool, err *tcpip.Error) {
+ // Invoke the tcp probe if installed. The tcp probe function will update
+ // the TCPEndpointState after the segment is processed.
+ defer e.probeSegment()
if s.flagIsSet(header.TCPFlagRst) {
if ok, err := e.handleReset(s); !ok {
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 682687ebe..39ea38fe6 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -2692,15 +2692,14 @@ func (e *endpoint) maybeEnableTimestamp(synOpts *header.TCPSynOptions) {
// timestamp returns the timestamp value to be used in the TSVal field of the
// timestamp option for outgoing TCP segments for a given endpoint.
func (e *endpoint) timestamp() uint32 {
- return tcpTimeStamp(e.tsOffset)
+ return tcpTimeStamp(time.Now(), e.tsOffset)
}
// tcpTimeStamp returns a timestamp offset by the provided offset. This is
// not inlined above as it's used when SYN cookies are in use and endpoint
// is not created at the time when the SYN cookie is sent.
-func tcpTimeStamp(offset uint32) uint32 {
- now := time.Now()
- return uint32(now.Unix()*1000+int64(now.Nanosecond()/1e6)) + offset
+func tcpTimeStamp(curTime time.Time, offset uint32) uint32 {
+ return uint32(curTime.Unix()*1000+int64(curTime.Nanosecond()/1e6)) + offset
}
// timeStampOffset returns a randomized timestamp offset to be used when sending
@@ -2843,6 +2842,14 @@ func (e *endpoint) completeState() stack.TCPEndpointState {
WEst: cubic.wEst,
}
}
+
+ rc := e.snd.rc
+ s.Sender.RACKState = stack.TCPRACKState{
+ XmitTime: rc.xmitTime,
+ EndSequence: rc.endSequence,
+ FACK: rc.fack,
+ RTT: rc.rtt,
+ }
return s
}
diff --git a/pkg/tcpip/transport/tcp/rack.go b/pkg/tcpip/transport/tcp/rack.go
new file mode 100644
index 000000000..d969ca23a
--- /dev/null
+++ b/pkg/tcpip/transport/tcp/rack.go
@@ -0,0 +1,82 @@
+// 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
+
+import (
+ "time"
+
+ "gvisor.dev/gvisor/pkg/tcpip/seqnum"
+)
+
+// RACK is a loss detection algorithm used in TCP to detect packet loss and
+// reordering using transmission timestamp of the packets instead of packet or
+// sequence counts. To use RACK, SACK should be enabled on the connection.
+
+// rackControl stores the rack related fields.
+// See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-6.1
+//
+// +stateify savable
+type rackControl struct {
+ // xmitTime is the latest transmission timestamp of rackControl.seg.
+ xmitTime time.Time `state:".(unixTime)"`
+
+ // endSequence is the ending TCP sequence number of rackControl.seg.
+ endSequence seqnum.Value
+
+ // fack is the highest selectively or cumulatively acknowledged
+ // sequence.
+ fack seqnum.Value
+
+ // rtt is the RTT of the most recently delivered packet on the
+ // connection (either cumulatively acknowledged or selectively
+ // acknowledged) that was not marked invalid as a possible spurious
+ // retransmission.
+ rtt time.Duration
+}
+
+// Update will update the RACK related fields when an ACK has been received.
+// See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-7.2
+func (rc *rackControl) Update(seg *segment, ackSeg *segment, srtt time.Duration, offset uint32) {
+ rtt := time.Now().Sub(seg.xmitTime)
+
+ // If the ACK is for a retransmitted packet, do not update if it is a
+ // spurious inference which is determined by below checks:
+ // 1. When Timestamping option is available, if the TSVal is less than the
+ // transmit time of the most recent retransmitted packet.
+ // 2. When RTT calculated for the packet is less than the smoothed RTT
+ // for the connection.
+ // See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-7.2
+ // step 2
+ if seg.xmitCount > 1 {
+ if ackSeg.parsedOptions.TS && ackSeg.parsedOptions.TSEcr != 0 {
+ if ackSeg.parsedOptions.TSEcr < tcpTimeStamp(seg.xmitTime, offset) {
+ return
+ }
+ }
+ if rtt < srtt {
+ return
+ }
+ }
+
+ rc.rtt = rtt
+ // Update rc.xmitTime and rc.endSequence to the transmit time and
+ // ending sequence number of the packet which has been acknowledged
+ // most recently.
+ endSeq := seg.sequenceNumber.Add(seqnum.Size(seg.data.Size()))
+ if rc.xmitTime.Before(seg.xmitTime) || (seg.xmitTime.Equal(rc.xmitTime) && rc.endSequence.LessThan(endSeq)) {
+ rc.xmitTime = seg.xmitTime
+ rc.endSequence = endSeq
+ }
+}
diff --git a/pkg/tcpip/transport/tcp/rack_state.go b/pkg/tcpip/transport/tcp/rack_state.go
new file mode 100644
index 000000000..c9dc7e773
--- /dev/null
+++ b/pkg/tcpip/transport/tcp/rack_state.go
@@ -0,0 +1,29 @@
+// 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
+
+import (
+ "time"
+)
+
+// saveXmitTime is invoked by stateify.
+func (rc *rackControl) saveXmitTime() unixTime {
+ return unixTime{rc.xmitTime.Unix(), rc.xmitTime.UnixNano()}
+}
+
+// loadXmitTime is invoked by stateify.
+func (rc *rackControl) loadXmitTime(unix unixTime) {
+ rc.xmitTime = time.Unix(unix.second, unix.nano)
+}
diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go
index 5862c32f2..c55589c45 100644
--- a/pkg/tcpip/transport/tcp/snd.go
+++ b/pkg/tcpip/transport/tcp/snd.go
@@ -191,6 +191,10 @@ type sender struct {
// cc is the congestion control algorithm in use for this sender.
cc congestionControl
+
+ // rc has the fields needed for implementing RACK loss detection
+ // algorithm.
+ rc rackControl
}
// rtt is a synchronization wrapper used to appease stateify. See the comment
@@ -1272,21 +1276,21 @@ func (s *sender) checkDuplicateAck(seg *segment) (rtx bool) {
// handleRcvdSegment is called when a segment is received; it is responsible for
// updating the send-related state.
-func (s *sender) handleRcvdSegment(seg *segment) {
+func (s *sender) handleRcvdSegment(rcvdSeg *segment) {
// Check if we can extract an RTT measurement from this ack.
- if !seg.parsedOptions.TS && s.rttMeasureSeqNum.LessThan(seg.ackNumber) {
+ if !rcvdSeg.parsedOptions.TS && s.rttMeasureSeqNum.LessThan(rcvdSeg.ackNumber) {
s.updateRTO(time.Now().Sub(s.rttMeasureTime))
s.rttMeasureSeqNum = s.sndNxt
}
// Update Timestamp if required. See RFC7323, section-4.3.
- if s.ep.sendTSOk && seg.parsedOptions.TS {
- s.ep.updateRecentTimestamp(seg.parsedOptions.TSVal, s.maxSentAck, seg.sequenceNumber)
+ if s.ep.sendTSOk && rcvdSeg.parsedOptions.TS {
+ s.ep.updateRecentTimestamp(rcvdSeg.parsedOptions.TSVal, s.maxSentAck, rcvdSeg.sequenceNumber)
}
// Insert SACKBlock information into our scoreboard.
if s.ep.sackPermitted {
- for _, sb := range seg.parsedOptions.SACKBlocks {
+ for _, sb := range rcvdSeg.parsedOptions.SACKBlocks {
// Only insert the SACK block if the following holds
// true:
// * SACK block acks data after the ack number in the
@@ -1299,27 +1303,27 @@ func (s *sender) handleRcvdSegment(seg *segment) {
// NOTE: This check specifically excludes DSACK blocks
// which have start/end before sndUna and are used to
// indicate spurious retransmissions.
- if seg.ackNumber.LessThan(sb.Start) && s.sndUna.LessThan(sb.Start) && sb.End.LessThanEq(s.sndNxt) && !s.ep.scoreboard.IsSACKED(sb) {
+ if rcvdSeg.ackNumber.LessThan(sb.Start) && s.sndUna.LessThan(sb.Start) && sb.End.LessThanEq(s.sndNxt) && !s.ep.scoreboard.IsSACKED(sb) {
s.ep.scoreboard.Insert(sb)
- seg.hasNewSACKInfo = true
+ rcvdSeg.hasNewSACKInfo = true
}
}
s.SetPipe()
}
// Count the duplicates and do the fast retransmit if needed.
- rtx := s.checkDuplicateAck(seg)
+ rtx := s.checkDuplicateAck(rcvdSeg)
// Stash away the current window size.
- s.sndWnd = seg.window
+ s.sndWnd = rcvdSeg.window
- ack := seg.ackNumber
+ ack := rcvdSeg.ackNumber
// Disable zero window probing if remote advertizes a non-zero receive
// window. This can be with an ACK to the zero window probe (where the
// acknumber refers to the already acknowledged byte) OR to any previously
// unacknowledged segment.
- if s.zeroWindowProbing && seg.window > 0 &&
+ if s.zeroWindowProbing && rcvdSeg.window > 0 &&
(ack == s.sndUna || (ack-1).InRange(s.sndUna, s.sndNxt)) {
s.disableZeroWindowProbing()
}
@@ -1344,10 +1348,10 @@ func (s *sender) handleRcvdSegment(seg *segment) {
// averaged RTT measurement only if the segment acknowledges
// some new data, i.e., only if it advances the left edge of
// the send window.
- if s.ep.sendTSOk && seg.parsedOptions.TSEcr != 0 {
+ if s.ep.sendTSOk && rcvdSeg.parsedOptions.TSEcr != 0 {
// TSVal/Ecr values sent by Netstack are at a millisecond
// granularity.
- elapsed := time.Duration(s.ep.timestamp()-seg.parsedOptions.TSEcr) * time.Millisecond
+ elapsed := time.Duration(s.ep.timestamp()-rcvdSeg.parsedOptions.TSEcr) * time.Millisecond
s.updateRTO(elapsed)
}
@@ -1361,6 +1365,9 @@ func (s *sender) handleRcvdSegment(seg *segment) {
ackLeft := acked
originalOutstanding := s.outstanding
+ s.rtt.Lock()
+ srtt := s.rtt.srtt
+ s.rtt.Unlock()
for ackLeft > 0 {
// We use logicalLen here because we can have FIN
// segments (which are always at the end of list) that
@@ -1380,6 +1387,11 @@ func (s *sender) handleRcvdSegment(seg *segment) {
s.writeNext = seg.Next()
}
+ // Update the RACK fields if SACK is enabled.
+ if s.ep.sackPermitted {
+ s.rc.Update(seg, rcvdSeg, srtt, s.ep.tsOffset)
+ }
+
s.writeList.Remove(seg)
// if SACK is enabled then Only reduce outstanding if
@@ -1435,7 +1447,7 @@ func (s *sender) handleRcvdSegment(seg *segment) {
// that the window opened up, or the congestion window was inflated due
// to a duplicate ack during fast recovery. This will also re-enable
// the retransmit timer if needed.
- if !s.ep.sackPermitted || s.fr.active || s.dupAckCount == 0 || seg.hasNewSACKInfo {
+ if !s.ep.sackPermitted || s.fr.active || s.dupAckCount == 0 || rcvdSeg.hasNewSACKInfo {
s.sendData()
}
}
diff --git a/pkg/tcpip/transport/tcp/tcp_rack_test.go b/pkg/tcpip/transport/tcp/tcp_rack_test.go
new file mode 100644
index 000000000..e03f101e8
--- /dev/null
+++ b/pkg/tcpip/transport/tcp/tcp_rack_test.go
@@ -0,0 +1,74 @@
+// 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_test
+
+import (
+ "testing"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/tcpip"
+ "gvisor.dev/gvisor/pkg/tcpip/buffer"
+ "gvisor.dev/gvisor/pkg/tcpip/header"
+ "gvisor.dev/gvisor/pkg/tcpip/stack"
+ "gvisor.dev/gvisor/pkg/tcpip/transport/tcp/testing/context"
+)
+
+// TestRACKUpdate tests the RACK related fields are updated when an ACK is
+// received on a SACK enabled connection.
+func TestRACKUpdate(t *testing.T) {
+ const maxPayload = 10
+ const tsOptionSize = 12
+ const maxTCPOptionSize = 40
+
+ c := context.New(t, uint32(header.TCPMinimumSize+header.IPv4MinimumSize+maxTCPOptionSize+maxPayload))
+ defer c.Cleanup()
+
+ var xmitTime time.Time
+ c.Stack().AddTCPProbe(func(state stack.TCPEndpointState) {
+ // Validate that the endpoint Sender.RACKState is what we expect.
+ if state.Sender.RACKState.XmitTime.Before(xmitTime) {
+ t.Fatalf("RACK transmit time failed to update when an ACK is received")
+ }
+
+ gotSeq := state.Sender.RACKState.EndSequence
+ wantSeq := state.Sender.SndNxt
+ if !gotSeq.LessThanEq(wantSeq) || gotSeq.LessThan(wantSeq) {
+ t.Fatalf("RACK sequence number failed to update, got: %v, but want: %v", gotSeq, wantSeq)
+ }
+
+ if state.Sender.RACKState.RTT == 0 {
+ t.Fatalf("RACK RTT failed to update when an ACK is received")
+ }
+ })
+ setStackSACKPermitted(t, c, true)
+ createConnectedWithSACKAndTS(c)
+
+ data := buffer.NewView(maxPayload)
+ for i := range data {
+ data[i] = byte(i)
+ }
+
+ // Write the data.
+ xmitTime = time.Now()
+ if _, _, err := c.EP.Write(tcpip.SlicePayload(data), tcpip.WriteOptions{}); err != nil {
+ t.Fatalf("Write failed: %s", err)
+ }
+
+ bytesRead := 0
+ c.ReceiveAndCheckPacketWithOptions(data, bytesRead, maxPayload, tsOptionSize)
+ bytesRead += maxPayload
+ c.SendAck(790, bytesRead)
+ time.Sleep(200 * time.Millisecond)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 17:18:20 +0000