From b1683df90bf81974e9e309ed66edaff30537c1be Mon Sep 17 00:00:00 2001 From: Zhaozhong Ni Date: Tue, 10 Jul 2018 09:22:37 -0700 Subject: netstack: tcp socket connected state S/R support. PiperOrigin-RevId: 203958972 Change-Id: Ia6fe16547539296d48e2c6731edacdd96bd6e93c --- pkg/tcpip/transport/tcp/BUILD | 7 ++ pkg/tcpip/transport/tcp/accept.go | 11 +- pkg/tcpip/transport/tcp/connect.go | 43 ++++++- pkg/tcpip/transport/tcp/endpoint.go | 72 ++++++++--- pkg/tcpip/transport/tcp/endpoint_state.go | 193 +++++++++++++++++++++--------- pkg/tcpip/transport/tcp/segment.go | 8 +- pkg/tcpip/transport/tcp/segment_queue.go | 4 +- pkg/tcpip/transport/tcp/segment_state.go | 51 ++++++++ pkg/tcpip/transport/tcp/snd.go | 4 +- pkg/tcpip/transport/tcp/snd_state.go | 49 ++++++++ 10 files changed, 352 insertions(+), 90 deletions(-) create mode 100644 pkg/tcpip/transport/tcp/segment_state.go create mode 100644 pkg/tcpip/transport/tcp/snd_state.go (limited to 'pkg/tcpip/transport/tcp') diff --git a/pkg/tcpip/transport/tcp/BUILD b/pkg/tcpip/transport/tcp/BUILD index 6cb0ebab2..6a2f42a12 100644 --- a/pkg/tcpip/transport/tcp/BUILD +++ b/pkg/tcpip/transport/tcp/BUILD @@ -10,11 +10,16 @@ go_stateify( "endpoint.go", "endpoint_state.go", "rcv.go", + "segment.go", "segment_heap.go", + "segment_queue.go", + "segment_state.go", "snd.go", + "snd_state.go", "tcp_segment_list.go", ], out = "tcp_state.go", + imports = ["gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"], package = "tcp", ) @@ -43,7 +48,9 @@ go_library( "segment.go", "segment_heap.go", "segment_queue.go", + "segment_state.go", "snd.go", + "snd_state.go", "tcp_segment_list.go", "tcp_state.go", "timer.go", diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go index ae4359ff4..d6d2b4555 100644 --- a/pkg/tcpip/transport/tcp/accept.go +++ b/pkg/tcpip/transport/tcp/accept.go @@ -78,7 +78,8 @@ func encodeMSS(mss uint16) uint32 { // to go above a threshold. var synRcvdCount struct { sync.Mutex - value uint64 + value uint64 + pending sync.WaitGroup } // listenContext is used by a listening endpoint to store state used while @@ -112,6 +113,7 @@ func incSynRcvdCount() bool { return false } + synRcvdCount.pending.Add(1) synRcvdCount.value++ return true @@ -125,6 +127,7 @@ func decSynRcvdCount() { defer synRcvdCount.Unlock() synRcvdCount.value-- + synRcvdCount.pending.Done() } // newListenContext creates a new listen context. @@ -302,7 +305,7 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) { opts := parseSynSegmentOptions(s) if incSynRcvdCount() { s.incRef() - go e.handleSynSegment(ctx, s, &opts) // S/R-FIXME + go e.handleSynSegment(ctx, s, &opts) // S/R-SAFE: synRcvdCount is the barrier. } else { cookie := ctx.createCookie(s.id, s.sequenceNumber, encodeMSS(opts.MSS)) // Send SYN with window scaling because we currently @@ -391,10 +394,12 @@ func (e *endpoint) protocolListenLoop(rcvWnd seqnum.Size) *tcpip.Error { return nil } if n¬ifyDrain != 0 { - for s := e.segmentQueue.dequeue(); s != nil; s = e.segmentQueue.dequeue() { + for !e.segmentQueue.empty() { + s := e.segmentQueue.dequeue() e.handleListenSegment(ctx, s) s.decRef() } + synRcvdCount.pending.Wait() close(e.drainDone) <-e.undrain } diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index afdea2b53..33bf4fc0b 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -453,7 +453,8 @@ func (h *handshake) execute() *tcpip.Error { return tcpip.ErrAborted } if n¬ifyDrain != 0 { - for s := h.ep.segmentQueue.dequeue(); s != nil; s = h.ep.segmentQueue.dequeue() { + for !h.ep.segmentQueue.empty() { + s := h.ep.segmentQueue.dequeue() err := h.handleSegment(s) s.decRef() if err != nil { @@ -823,15 +824,13 @@ func (e *endpoint) handleSegments() *tcpip.Error { // protocolMainLoop is the main loop of the TCP protocol. It runs in its own // goroutine and is responsible for sending segments and handling received // segments. -func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error { +func (e *endpoint) protocolMainLoop(handshake bool) *tcpip.Error { var closeTimer *time.Timer var closeWaker sleep.Waker defer func() { // e.mu is expected to be hold upon entering this section. - e.completeWorkerLocked() - if e.snd != nil { e.snd.resendTimer.cleanup() } @@ -840,6 +839,8 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error { closeTimer.Stop() } + e.completeWorkerLocked() + if e.drainDone != nil { close(e.drainDone) } @@ -850,7 +851,7 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error { e.waiterQueue.Notify(waiter.EventHUp | waiter.EventErr | waiter.EventIn | waiter.EventOut) }() - if !passive { + if handshake { // This is an active connection, so we must initiate the 3-way // handshake, and then inform potential waiters about its // completion. @@ -960,6 +961,17 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error { closeWaker.Assert() }) } + + if n¬ifyDrain != 0 { + for !e.segmentQueue.empty() { + if err := e.handleSegments(); err != nil { + return err + } + } + close(e.drainDone) + <-e.undrain + } + return nil }, }, @@ -971,6 +983,27 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error { s.AddWaker(funcs[i].w, i) } + // The following assertions and notifications are needed for restored + // endpoints. Fresh newly created endpoints have empty states and should + // not invoke any. + e.segmentQueue.mu.Lock() + if !e.segmentQueue.list.Empty() { + e.newSegmentWaker.Assert() + } + e.segmentQueue.mu.Unlock() + + e.rcvListMu.Lock() + if !e.rcvList.Empty() { + e.waiterQueue.Notify(waiter.EventIn) + } + e.rcvListMu.Unlock() + + e.mu.RLock() + if e.workerCleanup { + e.notifyProtocolGoroutine(notifyClose) + } + e.mu.RUnlock() + // Main loop. Handle segments until both send and receive ends of the // connection have completed. for !e.rcv.closed || !e.snd.closed || e.snd.sndUna != e.snd.sndNxtList { diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index cb105b863..8b9a81f6a 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -80,7 +80,7 @@ type endpoint struct { // change throughout the lifetime of the endpoint. stack *stack.Stack `state:"manual"` netProto tcpip.NetworkProtocolNumber - waiterQueue *waiter.Queue + waiterQueue *waiter.Queue `state:"wait"` // lastError represents the last error that the endpoint reported; // access to it is protected by the following mutex. @@ -95,8 +95,8 @@ type endpoint struct { // to indicate to users that no more data is coming. // // rcvListMu can be taken after the endpoint mu below. - rcvListMu sync.Mutex `state:"nosave"` - rcvList segmentList + rcvListMu sync.Mutex `state:"nosave"` + rcvList segmentList `state:"wait"` rcvClosed bool rcvBufSize int rcvBufUsed int @@ -104,8 +104,8 @@ type endpoint struct { // The following fields are protected by the mutex. mu sync.RWMutex `state:"nosave"` id stack.TransportEndpointID - state endpointState - isPortReserved bool `state:"manual"` + state endpointState `state:".(endpointState)"` + isPortReserved bool `state:"manual"` isRegistered bool boundNICID tcpip.NICID `state:"manual"` route stack.Route `state:"manual"` @@ -131,7 +131,7 @@ type endpoint struct { // workerCleanup specifies if the worker goroutine must perform cleanup // before exitting. This can only be set to true when workerRunning is // also true, and they're both protected by the mutex. - workerCleanup bool `state:"zerovalue"` + workerCleanup bool // sendTSOk is used to indicate when the TS Option has been negotiated. // When sendTSOk is true every non-RST segment should carry a TS as per @@ -166,7 +166,7 @@ type endpoint struct { // segmentQueue is used to hand received segments to the protocol // goroutine. Segments are queued as long as the queue is not full, // and dropped when it is. - segmentQueue segmentQueue `state:"zerovalue"` + segmentQueue segmentQueue `state:"wait"` // The following fields are used to manage the send buffer. When // segments are ready to be sent, they are added to sndQueue and the @@ -179,7 +179,7 @@ type endpoint struct { sndBufUsed int sndClosed bool sndBufInQueue seqnum.Size - sndQueue segmentList + sndQueue segmentList `state:"wait"` sndWaker sleep.Waker `state:"manual"` sndCloseWaker sleep.Waker `state:"manual"` @@ -201,17 +201,21 @@ type endpoint struct { // notifyFlags is a bitmask of flags used to indicate to the protocol // goroutine what it was notified; this is only accessed atomically. - notifyFlags uint32 `state:"zerovalue"` + notifyFlags uint32 `state:"nosave"` // acceptedChan is used by a listening endpoint protocol goroutine to // send newly accepted connections to the endpoint so that they can be // read by Accept() calls. - acceptedChan chan *endpoint `state:".(endpointChan)"` + acceptedChan chan *endpoint `state:"manual"` + + // acceptedEndpoints is only used to save / restore the channel buffer. + // FIXME + acceptedEndpoints []*endpoint // The following are only used from the protocol goroutine, and // therefore don't need locks to protect them. - rcv *receiver - snd *sender + rcv *receiver `state:"wait"` + snd *sender `state:"wait"` // The goroutine drain completion notification channel. drainDone chan struct{} `state:"nosave"` @@ -224,6 +228,7 @@ type endpoint struct { probe stack.TCPProbeFunc `state:"nosave"` // The following are only used to assist the restore run to re-connect. + bindAddress tcpip.Address connectingAddress tcpip.Address } @@ -357,6 +362,7 @@ func (e *endpoint) Close() { // Either perform the local cleanup or kick the worker to make sure it // knows it needs to cleanup. + tcpip.AddDanglingEndpoint(e) if !e.workerRunning { e.cleanupLocked() } else { @@ -376,9 +382,12 @@ func (e *endpoint) cleanupLocked() { if e.acceptedChan != nil { close(e.acceptedChan) for n := range e.acceptedChan { + n.mu.Lock() n.resetConnectionLocked(tcpip.ErrConnectionAborted) + n.mu.Unlock() n.Close() } + e.acceptedChan = nil } e.workerCleanup = false @@ -387,6 +396,7 @@ func (e *endpoint) cleanupLocked() { } e.route.Release() + tcpip.DeleteDanglingEndpoint(e) } // Read reads data from the endpoint. @@ -801,6 +811,16 @@ func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress) (tcpip.NetworkProtocol // Connect connects the endpoint to its peer. func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error { + return e.connect(addr, true, true) +} + +// connect connects the endpoint to its peer. In the normal non-S/R case, the +// new connection is expected to run the main goroutine and perform handshake. +// In restore of previously connected endpoints, both ends will be passively +// created (so no new handshaking is done); for stack-accepted connections not +// yet accepted by the app, they are restored without running the main goroutine +// here. +func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) *tcpip.Error { e.mu.Lock() defer e.mu.Unlock() @@ -912,9 +932,27 @@ func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error { e.boundNICID = nicid e.effectiveNetProtos = netProtos e.connectingAddress = connectingAddr - e.workerRunning = true - go e.protocolMainLoop(false) // S/R-SAFE: will be drained before save. + // Connect in the restore phase does not perform handshake. Restore its + // connection setting here. + if !handshake { + e.segmentQueue.mu.Lock() + for _, l := range []segmentList{e.segmentQueue.list, e.sndQueue, e.snd.writeList} { + for s := l.Front(); s != nil; s = s.Next() { + s.id = e.id + s.route = r.Clone() + e.sndWaker.Assert() + } + } + e.segmentQueue.mu.Unlock() + e.snd.updateMaxPayloadSize(int(e.route.MTU()), 0) + e.state = stateConnected + } + + if run { + e.workerRunning = true + go e.protocolMainLoop(handshake) // S/R-SAFE: will be drained before save. + } return tcpip.ErrConnectStarted } @@ -999,6 +1037,9 @@ func (e *endpoint) Listen(backlog int) *tcpip.Error { if len(e.acceptedChan) > backlog { return tcpip.ErrInvalidEndpointState } + if cap(e.acceptedChan) == backlog { + return nil + } origChan := e.acceptedChan e.acceptedChan = make(chan *endpoint, backlog) close(origChan) @@ -1036,7 +1077,7 @@ func (e *endpoint) Listen(backlog int) *tcpip.Error { func (e *endpoint) startAcceptedLoop(waiterQueue *waiter.Queue) { e.waiterQueue = waiterQueue e.workerRunning = true - go e.protocolMainLoop(true) // S/R-FIXME + go e.protocolMainLoop(false) // S/R-SAFE: drained on save. } // Accept returns a new endpoint if a peer has established a connection @@ -1077,6 +1118,7 @@ func (e *endpoint) Bind(addr tcpip.FullAddress, commit func() *tcpip.Error) (ret return tcpip.ErrAlreadyBound } + e.bindAddress = addr.Addr netProto, err := e.checkV4Mapped(&addr) if err != nil { return err diff --git a/pkg/tcpip/transport/tcp/endpoint_state.go b/pkg/tcpip/transport/tcp/endpoint_state.go index aa4ccea75..43765d425 100644 --- a/pkg/tcpip/transport/tcp/endpoint_state.go +++ b/pkg/tcpip/transport/tcp/endpoint_state.go @@ -17,8 +17,10 @@ package tcp import ( "fmt" "sync" + "time" "gvisor.googlesource.com/gvisor/pkg/tcpip" + "gvisor.googlesource.com/gvisor/pkg/tcpip/header" "gvisor.googlesource.com/gvisor/pkg/tcpip/stack" ) @@ -32,7 +34,7 @@ func (e *endpoint) drainSegmentLocked() { e.undrain = make(chan struct{}) e.mu.Unlock() - e.notificationWaker.Assert() + e.notifyProtocolGoroutine(notifyDrain) <-e.drainDone e.mu.Lock() @@ -48,37 +50,103 @@ func (e *endpoint) beforeSave() { switch e.state { case stateInitial, stateBound: - case stateListen: - if !e.segmentQueue.empty() { - e.drainSegmentLocked() + case stateListen, stateConnecting, stateConnected: + if e.state == stateConnected && !e.workerRunning { + // The endpoint must be in acceptedChan. + break } - case stateConnecting: e.drainSegmentLocked() - if e.state != stateConnected { + if e.state != stateClosed && e.state != stateError { + if !e.workerRunning { + panic("endpoint has no worker running in listen, connecting, or connected state") + } break } fallthrough - case stateConnected: - // FIXME - panic(tcpip.ErrSaveRejection{fmt.Errorf("endpoint cannot be saved in connected state: local %v:%v, remote %v:%v", e.id.LocalAddress, e.id.LocalPort, e.id.RemoteAddress, e.id.RemotePort)}) - case stateClosed, stateError: + case stateError, stateClosed: + for e.state == stateError && e.workerRunning { + e.mu.Unlock() + time.Sleep(100 * time.Millisecond) + e.mu.Lock() + } if e.workerRunning { - panic(fmt.Sprintf("endpoint still has worker running in closed or error state")) + panic("endpoint still has worker running in closed or error state") } default: panic(fmt.Sprintf("endpoint in unknown state %v", e.state)) } + + if e.waiterQueue != nil && !e.waiterQueue.IsEmpty() { + panic("endpoint still has waiters upon save") + } + + if !((e.state == stateBound || e.state == stateListen) == e.isPortReserved) { + panic("endpoint port must and must only be reserved in bound or listen state") + } + + if e.acceptedChan != nil { + close(e.acceptedChan) + e.acceptedEndpoints = make([]*endpoint, len(e.acceptedChan), cap(e.acceptedChan)) + i := 0 + for ep := range e.acceptedChan { + e.acceptedEndpoints[i] = ep + i++ + } + if i != len(e.acceptedEndpoints) { + panic("endpoint acceptedChan buffer got consumed by background context") + } + } +} + +// saveState is invoked by stateify. +func (e *endpoint) saveState() endpointState { + return e.state +} + +// Endpoint loading must be done in the following ordering by their state, to +// avoid dangling connecting w/o listening peer, and to avoid conflicts in port +// reservation. +var connectedLoading sync.WaitGroup +var listenLoading sync.WaitGroup +var connectingLoading sync.WaitGroup + +// Bound endpoint loading happens last. + +// loadState is invoked by stateify. +func (e *endpoint) loadState(state endpointState) { + // This is to ensure that the loading wait groups include all applicable + // endpoints before any asynchronous calls to the Wait() methods. + switch state { + case stateConnected: + connectedLoading.Add(1) + case stateListen: + listenLoading.Add(1) + case stateConnecting: + connectingLoading.Add(1) + } + e.state = state } // afterLoad is invoked by stateify. func (e *endpoint) afterLoad() { + // We load acceptedChan buffer indirectly here. Note that closed + // endpoints might not need to allocate the channel. + // FIXME + if cap(e.acceptedEndpoints) > 0 { + e.acceptedChan = make(chan *endpoint, cap(e.acceptedEndpoints)) + for _, ep := range e.acceptedEndpoints { + e.acceptedChan <- ep + } + e.acceptedEndpoints = nil + } + e.stack = stack.StackFromEnv e.segmentQueue.setLimit(2 * e.rcvBufSize) e.workMu.Init() state := e.state switch state { - case stateInitial, stateBound, stateListen, stateConnecting: + case stateInitial, stateBound, stateListen, stateConnecting, stateConnected: var ss SendBufferSizeOption if err := e.stack.TransportProtocolOption(ProtocolNumber, &ss); err == nil { if e.sndBufSize < ss.Min || e.sndBufSize > ss.Max { @@ -90,65 +158,72 @@ func (e *endpoint) afterLoad() { } } - switch state { - case stateBound, stateListen, stateConnecting: + bind := func() { e.state = stateInitial - if err := e.Bind(tcpip.FullAddress{Addr: e.id.LocalAddress, Port: e.id.LocalPort}, nil); err != nil { + if len(e.bindAddress) == 0 { + e.bindAddress = e.id.LocalAddress + } + if err := e.Bind(tcpip.FullAddress{Addr: e.bindAddress, Port: e.id.LocalPort}, nil); err != nil { panic("endpoint binding failed: " + err.String()) } } switch state { - case stateListen: - backlog := cap(e.acceptedChan) - e.acceptedChan = nil - if err := e.Listen(backlog); err != nil { - panic("endpoint listening failed: " + err.String()) + case stateConnected: + bind() + if len(e.connectingAddress) == 0 { + // This endpoint is accepted by netstack but not yet by + // the app. If the endpoint is IPv6 but the remote + // address is IPv4, we need to connect as IPv6 so that + // dual-stack mode can be properly activated. + if e.netProto == header.IPv6ProtocolNumber && len(e.id.RemoteAddress) != header.IPv6AddressSize { + e.connectingAddress = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff" + e.id.RemoteAddress + } else { + e.connectingAddress = e.id.RemoteAddress + } } - } - - switch state { - case stateConnecting: - if err := e.Connect(tcpip.FullAddress{NIC: e.boundNICID, Addr: e.connectingAddress, Port: e.id.RemotePort}); err != tcpip.ErrConnectStarted { + if err := e.connect(tcpip.FullAddress{NIC: e.boundNICID, Addr: e.connectingAddress, Port: e.id.RemotePort}, false, e.workerRunning); err != tcpip.ErrConnectStarted { panic("endpoint connecting failed: " + err.String()) } + connectedLoading.Done() + case stateListen: + tcpip.AsyncLoading.Add(1) + go func() { + connectedLoading.Wait() + bind() + backlog := cap(e.acceptedChan) + if err := e.Listen(backlog); err != nil { + panic("endpoint listening failed: " + err.String()) + } + listenLoading.Done() + tcpip.AsyncLoading.Done() + }() + case stateConnecting: + tcpip.AsyncLoading.Add(1) + go func() { + connectedLoading.Wait() + listenLoading.Wait() + bind() + if err := e.Connect(tcpip.FullAddress{NIC: e.boundNICID, Addr: e.connectingAddress, Port: e.id.RemotePort}); err != tcpip.ErrConnectStarted { + panic("endpoint connecting failed: " + err.String()) + } + connectingLoading.Done() + tcpip.AsyncLoading.Done() + }() + case stateBound: + tcpip.AsyncLoading.Add(1) + go func() { + connectedLoading.Wait() + listenLoading.Wait() + connectingLoading.Wait() + bind() + tcpip.AsyncLoading.Done() + }() + case stateClosed, stateError: + tcpip.DeleteDanglingEndpoint(e) } } -// saveAcceptedChan is invoked by stateify. -func (e *endpoint) saveAcceptedChan() endpointChan { - if e.acceptedChan == nil { - return endpointChan{} - } - close(e.acceptedChan) - buffer := make([]*endpoint, 0, len(e.acceptedChan)) - for ep := range e.acceptedChan { - buffer = append(buffer, ep) - } - if len(buffer) != cap(buffer) { - panic("endpoint.acceptedChan buffer got consumed by background context") - } - c := cap(e.acceptedChan) - e.acceptedChan = nil - return endpointChan{buffer: buffer, cap: c} -} - -// loadAcceptedChan is invoked by stateify. -func (e *endpoint) loadAcceptedChan(c endpointChan) { - if c.cap == 0 { - return - } - e.acceptedChan = make(chan *endpoint, c.cap) - for _, ep := range c.buffer { - e.acceptedChan <- ep - } -} - -type endpointChan struct { - buffer []*endpoint - cap int -} - // saveLastError is invoked by stateify. func (e *endpoint) saveLastError() string { if e.lastError == nil { diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go index a90f6661d..40928ba2c 100644 --- a/pkg/tcpip/transport/tcp/segment.go +++ b/pkg/tcpip/transport/tcp/segment.go @@ -39,9 +39,9 @@ const ( type segment struct { segmentEntry refCnt int32 - id stack.TransportEndpointID - route stack.Route `state:"manual"` - data buffer.VectorisedView + id stack.TransportEndpointID `state:"manual"` + route stack.Route `state:"manual"` + data buffer.VectorisedView `state:".(buffer.VectorisedView)"` // views is used as buffer for data when its length is large // enough to store a VectorisedView. views [8]buffer.View @@ -55,7 +55,7 @@ type segment struct { // parsedOptions stores the parsed values from the options in the segment. parsedOptions header.TCPOptions - options []byte + options []byte `state:".([]byte)"` } func newSegment(r *stack.Route, id stack.TransportEndpointID, vv *buffer.VectorisedView) *segment { diff --git a/pkg/tcpip/transport/tcp/segment_queue.go b/pkg/tcpip/transport/tcp/segment_queue.go index 83f554ebd..2ddcf5f10 100644 --- a/pkg/tcpip/transport/tcp/segment_queue.go +++ b/pkg/tcpip/transport/tcp/segment_queue.go @@ -22,8 +22,8 @@ import ( // segmentQueue is a bounded, thread-safe queue of TCP segments. type segmentQueue struct { - mu sync.Mutex - list segmentList + mu sync.Mutex `state:"nosave"` + list segmentList `state:"wait"` limit int used int } diff --git a/pkg/tcpip/transport/tcp/segment_state.go b/pkg/tcpip/transport/tcp/segment_state.go new file mode 100644 index 000000000..22f0bbf18 --- /dev/null +++ b/pkg/tcpip/transport/tcp/segment_state.go @@ -0,0 +1,51 @@ +// Copyright 2018 Google Inc. +// +// 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 ( + "gvisor.googlesource.com/gvisor/pkg/tcpip/buffer" +) + +// saveData is invoked by stateify. +func (s *segment) saveData() buffer.VectorisedView { + // We cannot save s.data directly as s.data.views may alias to s.views, + // which is not allowed by state framework (in-struct pointer). + return s.data.Clone(nil) +} + +// loadData is invoked by stateify. +func (s *segment) loadData(data buffer.VectorisedView) { + // NOTE: We cannot do the s.data = data.Clone(s.views[:]) optimization + // here because data.views is not guaranteed to be loaded by now. Plus, + // data.views will be allocated anyway so there really is little point + // of utilizing s.views for data.views. + s.data = data +} + +// saveOptions is invoked by stateify. +func (s *segment) saveOptions() []byte { + // We cannot save s.options directly as it may point to s.data's trimmed + // tail, which is not allowed by state framework (in-struct pointer). + b := make([]byte, 0, cap(s.options)) + return append(b, s.options...) +} + +// loadOptions is invoked by stateify. +func (s *segment) loadOptions(options []byte) { + // NOTE: We cannot point s.options back into s.data's trimmed tail. But + // it is OK as they do not need to aliased. Plus, options is already + // allocated so there is no cost here. + s.options = options +} diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go index a9892eb64..7dfbf6384 100644 --- a/pkg/tcpip/transport/tcp/snd.go +++ b/pkg/tcpip/transport/tcp/snd.go @@ -38,7 +38,7 @@ type sender struct { ep *endpoint // lastSendTime is the timestamp when the last packet was sent. - lastSendTime time.Time + lastSendTime time.Time `state:".(unixTime)"` // dupAckCount is the number of duplicated acks received. It is used for // fast retransmit. @@ -81,7 +81,7 @@ type sender struct { rttMeasureSeqNum seqnum.Value // rttMeasureTime is the time when the rttMeasureSeqNum was sent. - rttMeasureTime time.Time + rttMeasureTime time.Time `state:".(unixTime)"` closed bool writeNext *segment diff --git a/pkg/tcpip/transport/tcp/snd_state.go b/pkg/tcpip/transport/tcp/snd_state.go new file mode 100644 index 000000000..33c8867f4 --- /dev/null +++ b/pkg/tcpip/transport/tcp/snd_state.go @@ -0,0 +1,49 @@ +// Copyright 2018 Google Inc. +// +// 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" +) + +type unixTime struct { + second int64 + nano int64 +} + +// saveLastSendTime is invoked by stateify. +func (s *sender) saveLastSendTime() unixTime { + return unixTime{s.lastSendTime.Unix(), s.lastSendTime.UnixNano()} +} + +// loadLastSendTime is invoked by stateify. +func (s *sender) loadLastSendTime(unix unixTime) { + s.lastSendTime = time.Unix(unix.second, unix.nano) +} + +// saveRttMeasureTime is invoked by stateify. +func (s *sender) saveRttMeasureTime() unixTime { + return unixTime{s.rttMeasureTime.Unix(), s.rttMeasureTime.UnixNano()} +} + +// loadRttMeasureTime is invoked by stateify. +func (s *sender) loadRttMeasureTime(unix unixTime) { + s.rttMeasureTime = time.Unix(unix.second, unix.nano) +} + +// afterLoad is invoked by stateify. +func (s *sender) afterLoad() { + s.resendTimer.init(&s.resendWaker) +} -- cgit v1.2.3