mirror of https://github.com/v2ray/v2ray-core
628 lines
14 KiB
Go
628 lines
14 KiB
Go
package kcp
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import (
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"io"
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"net"
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"sync"
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"sync/atomic"
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"time"
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"v2ray.com/core/app/log"
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"v2ray.com/core/common/buf"
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"v2ray.com/core/common/predicate"
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)
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var (
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ErrIOTimeout = newError("Read/Write timeout")
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ErrClosedListener = newError("Listener closed.")
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ErrClosedConnection = newError("Connection closed.")
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)
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type State int32
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func (s State) Is(states ...State) bool {
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for _, state := range states {
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if s == state {
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return true
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}
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}
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return false
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}
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const (
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StateActive State = 0
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StateReadyToClose State = 1
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StatePeerClosed State = 2
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StateTerminating State = 3
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StatePeerTerminating State = 4
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StateTerminated State = 5
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)
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func nowMillisec() int64 {
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now := time.Now()
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return now.Unix()*1000 + int64(now.Nanosecond()/1000000)
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}
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type RoundTripInfo struct {
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sync.RWMutex
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variation uint32
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srtt uint32
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rto uint32
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minRtt uint32
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updatedTimestamp uint32
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}
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func (v *RoundTripInfo) UpdatePeerRTO(rto uint32, current uint32) {
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v.Lock()
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defer v.Unlock()
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if current-v.updatedTimestamp < 3000 {
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return
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}
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v.updatedTimestamp = current
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v.rto = rto
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}
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func (v *RoundTripInfo) Update(rtt uint32, current uint32) {
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if rtt > 0x7FFFFFFF {
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return
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}
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v.Lock()
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defer v.Unlock()
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// https://tools.ietf.org/html/rfc6298
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if v.srtt == 0 {
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v.srtt = rtt
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v.variation = rtt / 2
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} else {
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delta := rtt - v.srtt
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if v.srtt > rtt {
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delta = v.srtt - rtt
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}
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v.variation = (3*v.variation + delta) / 4
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v.srtt = (7*v.srtt + rtt) / 8
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if v.srtt < v.minRtt {
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v.srtt = v.minRtt
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}
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}
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var rto uint32
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if v.minRtt < 4*v.variation {
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rto = v.srtt + 4*v.variation
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} else {
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rto = v.srtt + v.variation
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}
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if rto > 10000 {
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rto = 10000
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}
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v.rto = rto * 5 / 4
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v.updatedTimestamp = current
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}
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func (v *RoundTripInfo) Timeout() uint32 {
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v.RLock()
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defer v.RUnlock()
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return v.rto
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}
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func (v *RoundTripInfo) SmoothedTime() uint32 {
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v.RLock()
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defer v.RUnlock()
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return v.srtt
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}
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type Updater struct {
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interval int64
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shouldContinue predicate.Predicate
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shouldTerminate predicate.Predicate
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updateFunc func()
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notifier chan bool
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}
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func NewUpdater(interval uint32, shouldContinue predicate.Predicate, shouldTerminate predicate.Predicate, updateFunc func()) *Updater {
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u := &Updater{
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interval: int64(time.Duration(interval) * time.Millisecond),
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shouldContinue: shouldContinue,
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shouldTerminate: shouldTerminate,
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updateFunc: updateFunc,
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notifier: make(chan bool, 1),
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}
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go u.Run()
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return u
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}
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func (v *Updater) WakeUp() {
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select {
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case v.notifier <- true:
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default:
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}
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}
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func (v *Updater) Run() {
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for <-v.notifier {
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if v.shouldTerminate() {
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return
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}
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interval := v.Interval()
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for v.shouldContinue() {
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v.updateFunc()
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time.Sleep(interval)
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}
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}
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}
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func (u *Updater) Interval() time.Duration {
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return time.Duration(atomic.LoadInt64(&u.interval))
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}
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func (u *Updater) SetInterval(d time.Duration) {
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atomic.StoreInt64(&u.interval, int64(d))
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}
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type SystemConnection interface {
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net.Conn
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Reset(func([]Segment))
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Overhead() int
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}
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var (
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_ buf.MultiBufferReader = (*Connection)(nil)
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_ buf.MultiBufferWriter = (*Connection)(nil)
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)
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// Connection is a KCP connection over UDP.
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type Connection struct {
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conn SystemConnection
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rd time.Time
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wd time.Time // write deadline
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since int64
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dataInput chan bool
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dataOutput chan bool
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Config *Config
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conv uint16
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state State
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stateBeginTime uint32
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lastIncomingTime uint32
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lastPingTime uint32
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mss uint32
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roundTrip *RoundTripInfo
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receivingWorker *ReceivingWorker
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sendingWorker *SendingWorker
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output SegmentWriter
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dataUpdater *Updater
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pingUpdater *Updater
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mergingWriter buf.Writer
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}
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// NewConnection create a new KCP connection between local and remote.
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func NewConnection(conv uint16, sysConn SystemConnection, config *Config) *Connection {
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log.Trace(newError("creating connection ", conv))
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conn := &Connection{
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conv: conv,
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conn: sysConn,
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since: nowMillisec(),
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dataInput: make(chan bool, 1),
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dataOutput: make(chan bool, 1),
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Config: config,
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output: NewSegmentWriter(sysConn),
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mss: config.GetMTUValue() - uint32(sysConn.Overhead()) - DataSegmentOverhead,
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roundTrip: &RoundTripInfo{
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rto: 100,
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minRtt: config.GetTTIValue(),
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},
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}
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sysConn.Reset(conn.Input)
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conn.receivingWorker = NewReceivingWorker(conn)
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conn.sendingWorker = NewSendingWorker(conn)
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isTerminating := func() bool {
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return conn.State().Is(StateTerminating, StateTerminated)
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}
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isTerminated := func() bool {
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return conn.State() == StateTerminated
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}
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conn.dataUpdater = NewUpdater(
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config.GetTTIValue(),
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predicate.Not(isTerminating).And(predicate.Any(conn.sendingWorker.UpdateNecessary, conn.receivingWorker.UpdateNecessary)),
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isTerminating,
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conn.updateTask)
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conn.pingUpdater = NewUpdater(
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5000, // 5 seconds
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predicate.Not(isTerminated),
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isTerminated,
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conn.updateTask)
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conn.pingUpdater.WakeUp()
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return conn
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}
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func (v *Connection) Elapsed() uint32 {
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return uint32(nowMillisec() - v.since)
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}
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func (v *Connection) OnDataInput() {
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select {
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case v.dataInput <- true:
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default:
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}
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}
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func (v *Connection) OnDataOutput() {
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select {
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case v.dataOutput <- true:
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default:
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}
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}
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// ReadMultiBuffer implements buf.MultiBufferReader.
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func (v *Connection) ReadMultiBuffer() (buf.MultiBuffer, error) {
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if v == nil {
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return nil, io.EOF
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}
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for {
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if v.State().Is(StateReadyToClose, StateTerminating, StateTerminated) {
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return nil, io.EOF
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}
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mb := v.receivingWorker.ReadMultiBuffer()
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if !mb.IsEmpty() {
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return mb, nil
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}
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if v.State() == StatePeerTerminating {
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return nil, io.EOF
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}
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duration := time.Minute
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if !v.rd.IsZero() {
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duration = v.rd.Sub(time.Now())
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if duration < 0 {
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return nil, ErrIOTimeout
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}
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}
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select {
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case <-v.dataInput:
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case <-time.After(duration):
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if !v.rd.IsZero() && v.rd.Before(time.Now()) {
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return nil, ErrIOTimeout
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}
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}
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}
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}
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// Read implements the Conn Read method.
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func (v *Connection) Read(b []byte) (int, error) {
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if v == nil {
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return 0, io.EOF
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}
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for {
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if v.State().Is(StateReadyToClose, StateTerminating, StateTerminated) {
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return 0, io.EOF
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}
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nBytes := v.receivingWorker.Read(b)
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if nBytes > 0 {
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return nBytes, nil
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}
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if v.State() == StatePeerTerminating {
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return 0, io.EOF
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}
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duration := time.Minute
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if !v.rd.IsZero() {
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duration = v.rd.Sub(time.Now())
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if duration < 0 {
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return 0, ErrIOTimeout
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}
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}
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select {
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case <-v.dataInput:
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case <-time.After(duration):
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if !v.rd.IsZero() && v.rd.Before(time.Now()) {
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return 0, ErrIOTimeout
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}
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}
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}
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}
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// Write implements the Conn Write method.
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func (v *Connection) Write(b []byte) (int, error) {
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totalWritten := 0
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for {
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if v == nil || v.State() != StateActive {
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return totalWritten, io.ErrClosedPipe
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}
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nBytes := v.sendingWorker.Push(b[totalWritten:])
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v.dataUpdater.WakeUp()
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if nBytes > 0 {
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totalWritten += nBytes
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if totalWritten == len(b) {
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return totalWritten, nil
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}
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}
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duration := time.Minute
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if !v.wd.IsZero() {
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duration = v.wd.Sub(time.Now())
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if duration < 0 {
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return totalWritten, ErrIOTimeout
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}
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}
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select {
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case <-v.dataOutput:
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case <-time.After(duration):
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if !v.wd.IsZero() && v.wd.Before(time.Now()) {
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return totalWritten, ErrIOTimeout
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}
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}
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}
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}
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func (c *Connection) WriteMultiBuffer(mb buf.MultiBuffer) error {
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if c.mergingWriter == nil {
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c.mergingWriter = buf.NewMergingWriterSize(c, c.mss)
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}
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return c.mergingWriter.Write(mb)
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}
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func (v *Connection) SetState(state State) {
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current := v.Elapsed()
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atomic.StoreInt32((*int32)(&v.state), int32(state))
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atomic.StoreUint32(&v.stateBeginTime, current)
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log.Trace(newError("#", v.conv, " entering state ", state, " at ", current).AtDebug())
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switch state {
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case StateReadyToClose:
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v.receivingWorker.CloseRead()
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case StatePeerClosed:
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v.sendingWorker.CloseWrite()
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case StateTerminating:
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v.receivingWorker.CloseRead()
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v.sendingWorker.CloseWrite()
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v.pingUpdater.SetInterval(time.Second)
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case StatePeerTerminating:
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v.sendingWorker.CloseWrite()
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v.pingUpdater.SetInterval(time.Second)
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case StateTerminated:
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v.receivingWorker.CloseRead()
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v.sendingWorker.CloseWrite()
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v.pingUpdater.SetInterval(time.Second)
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v.dataUpdater.WakeUp()
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v.pingUpdater.WakeUp()
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go v.Terminate()
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}
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}
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// Close closes the connection.
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func (v *Connection) Close() error {
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if v == nil {
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return ErrClosedConnection
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}
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v.OnDataInput()
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v.OnDataOutput()
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state := v.State()
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if state.Is(StateReadyToClose, StateTerminating, StateTerminated) {
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return ErrClosedConnection
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}
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log.Trace(newError("closing connection to ", v.conn.RemoteAddr()))
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if state == StateActive {
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v.SetState(StateReadyToClose)
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}
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if state == StatePeerClosed {
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v.SetState(StateTerminating)
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}
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if state == StatePeerTerminating {
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v.SetState(StateTerminated)
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}
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return nil
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}
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// LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
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func (v *Connection) LocalAddr() net.Addr {
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if v == nil {
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return nil
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}
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return v.conn.LocalAddr()
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}
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// RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
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func (v *Connection) RemoteAddr() net.Addr {
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if v == nil {
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return nil
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}
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return v.conn.RemoteAddr()
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}
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// SetDeadline sets the deadline associated with the listener. A zero time value disables the deadline.
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func (v *Connection) SetDeadline(t time.Time) error {
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if err := v.SetReadDeadline(t); err != nil {
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return err
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}
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if err := v.SetWriteDeadline(t); err != nil {
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return err
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}
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return nil
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}
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// SetReadDeadline implements the Conn SetReadDeadline method.
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func (v *Connection) SetReadDeadline(t time.Time) error {
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if v == nil || v.State() != StateActive {
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return ErrClosedConnection
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}
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v.rd = t
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return nil
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}
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// SetWriteDeadline implements the Conn SetWriteDeadline method.
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func (v *Connection) SetWriteDeadline(t time.Time) error {
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if v == nil || v.State() != StateActive {
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return ErrClosedConnection
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}
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v.wd = t
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return nil
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}
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// kcp update, input loop
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func (v *Connection) updateTask() {
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v.flush()
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}
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func (v *Connection) Terminate() {
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if v == nil {
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return
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}
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log.Trace(newError("terminating connection to ", v.RemoteAddr()))
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//v.SetState(StateTerminated)
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v.OnDataInput()
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v.OnDataOutput()
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v.conn.Close()
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v.sendingWorker.Release()
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v.receivingWorker.Release()
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}
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func (v *Connection) HandleOption(opt SegmentOption) {
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if (opt & SegmentOptionClose) == SegmentOptionClose {
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v.OnPeerClosed()
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}
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}
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func (v *Connection) OnPeerClosed() {
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state := v.State()
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if state == StateReadyToClose {
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v.SetState(StateTerminating)
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}
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if state == StateActive {
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v.SetState(StatePeerClosed)
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}
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}
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// Input when you received a low level packet (eg. UDP packet), call it
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func (v *Connection) Input(segments []Segment) {
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current := v.Elapsed()
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atomic.StoreUint32(&v.lastIncomingTime, current)
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for _, seg := range segments {
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if seg.Conversation() != v.conv {
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break
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}
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switch seg := seg.(type) {
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case *DataSegment:
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v.HandleOption(seg.Option)
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v.receivingWorker.ProcessSegment(seg)
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if v.receivingWorker.IsDataAvailable() {
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v.OnDataInput()
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}
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v.dataUpdater.WakeUp()
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case *AckSegment:
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v.HandleOption(seg.Option)
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v.sendingWorker.ProcessSegment(current, seg, v.roundTrip.Timeout())
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v.OnDataOutput()
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v.dataUpdater.WakeUp()
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case *CmdOnlySegment:
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v.HandleOption(seg.Option)
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if seg.Command() == CommandTerminate {
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state := v.State()
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if state == StateActive ||
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state == StatePeerClosed {
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v.SetState(StatePeerTerminating)
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} else if state == StateReadyToClose {
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v.SetState(StateTerminating)
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} else if state == StateTerminating {
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v.SetState(StateTerminated)
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}
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}
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if seg.Option == SegmentOptionClose || seg.Command() == CommandTerminate {
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v.OnDataInput()
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v.OnDataOutput()
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}
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v.sendingWorker.ProcessReceivingNext(seg.ReceivinNext)
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v.receivingWorker.ProcessSendingNext(seg.SendingNext)
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v.roundTrip.UpdatePeerRTO(seg.PeerRTO, current)
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seg.Release()
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default:
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}
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}
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}
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func (v *Connection) flush() {
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current := v.Elapsed()
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if v.State() == StateTerminated {
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return
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}
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if v.State() == StateActive && current-atomic.LoadUint32(&v.lastIncomingTime) >= 30000 {
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v.Close()
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}
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if v.State() == StateReadyToClose && v.sendingWorker.IsEmpty() {
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v.SetState(StateTerminating)
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}
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if v.State() == StateTerminating {
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log.Trace(newError("#", v.conv, " sending terminating cmd.").AtDebug())
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v.Ping(current, CommandTerminate)
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if current-atomic.LoadUint32(&v.stateBeginTime) > 8000 {
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|
v.SetState(StateTerminated)
|
|
}
|
|
return
|
|
}
|
|
if v.State() == StatePeerTerminating && current-atomic.LoadUint32(&v.stateBeginTime) > 4000 {
|
|
v.SetState(StateTerminating)
|
|
}
|
|
|
|
if v.State() == StateReadyToClose && current-atomic.LoadUint32(&v.stateBeginTime) > 15000 {
|
|
v.SetState(StateTerminating)
|
|
}
|
|
|
|
// flush acknowledges
|
|
v.receivingWorker.Flush(current)
|
|
v.sendingWorker.Flush(current)
|
|
|
|
if current-atomic.LoadUint32(&v.lastPingTime) >= 3000 {
|
|
v.Ping(current, CommandPing)
|
|
}
|
|
}
|
|
|
|
func (v *Connection) State() State {
|
|
return State(atomic.LoadInt32((*int32)(&v.state)))
|
|
}
|
|
|
|
func (v *Connection) Ping(current uint32, cmd Command) {
|
|
seg := NewCmdOnlySegment()
|
|
seg.Conv = v.conv
|
|
seg.Cmd = cmd
|
|
seg.ReceivinNext = v.receivingWorker.NextNumber()
|
|
seg.SendingNext = v.sendingWorker.FirstUnacknowledged()
|
|
seg.PeerRTO = v.roundTrip.Timeout()
|
|
if v.State() == StateReadyToClose {
|
|
seg.Option = SegmentOptionClose
|
|
}
|
|
v.output.Write(seg)
|
|
atomic.StoreUint32(&v.lastPingTime, current)
|
|
seg.Release()
|
|
}
|