mirror of
https://github.com/XTLS/Xray-core.git
synced 2024-09-08 17:29:20 +03:00
662 lines
14 KiB
Go
662 lines
14 KiB
Go
package kcp
|
|
|
|
import (
|
|
"bytes"
|
|
"io"
|
|
"net"
|
|
"runtime"
|
|
"sync"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"github.com/xtls/xray-core/common/buf"
|
|
"github.com/xtls/xray-core/common/signal"
|
|
"github.com/xtls/xray-core/common/signal/semaphore"
|
|
)
|
|
|
|
var (
|
|
ErrIOTimeout = newError("Read/Write timeout")
|
|
ErrClosedListener = newError("Listener closed.")
|
|
ErrClosedConnection = newError("Connection closed.")
|
|
)
|
|
|
|
// State of the connection
|
|
type State int32
|
|
|
|
// Is returns true if current State is one of the candidates.
|
|
func (s State) Is(states ...State) bool {
|
|
for _, state := range states {
|
|
if s == state {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
const (
|
|
StateActive State = 0 // Connection is active
|
|
StateReadyToClose State = 1 // Connection is closed locally
|
|
StatePeerClosed State = 2 // Connection is closed on remote
|
|
StateTerminating State = 3 // Connection is ready to be destroyed locally
|
|
StatePeerTerminating State = 4 // Connection is ready to be destroyed on remote
|
|
StateTerminated State = 5 // Connection is destroyed.
|
|
)
|
|
|
|
func nowMillisec() int64 {
|
|
now := time.Now()
|
|
return now.Unix()*1000 + int64(now.Nanosecond()/1000000)
|
|
}
|
|
|
|
type RoundTripInfo struct {
|
|
sync.RWMutex
|
|
variation uint32
|
|
srtt uint32
|
|
rto uint32
|
|
minRtt uint32
|
|
updatedTimestamp uint32
|
|
}
|
|
|
|
func (info *RoundTripInfo) UpdatePeerRTO(rto uint32, current uint32) {
|
|
info.Lock()
|
|
defer info.Unlock()
|
|
|
|
if current-info.updatedTimestamp < 3000 {
|
|
return
|
|
}
|
|
|
|
info.updatedTimestamp = current
|
|
info.rto = rto
|
|
}
|
|
|
|
func (info *RoundTripInfo) Update(rtt uint32, current uint32) {
|
|
if rtt > 0x7FFFFFFF {
|
|
return
|
|
}
|
|
info.Lock()
|
|
defer info.Unlock()
|
|
|
|
// https://tools.ietf.org/html/rfc6298
|
|
if info.srtt == 0 {
|
|
info.srtt = rtt
|
|
info.variation = rtt / 2
|
|
} else {
|
|
delta := rtt - info.srtt
|
|
if info.srtt > rtt {
|
|
delta = info.srtt - rtt
|
|
}
|
|
info.variation = (3*info.variation + delta) / 4
|
|
info.srtt = (7*info.srtt + rtt) / 8
|
|
if info.srtt < info.minRtt {
|
|
info.srtt = info.minRtt
|
|
}
|
|
}
|
|
var rto uint32
|
|
if info.minRtt < 4*info.variation {
|
|
rto = info.srtt + 4*info.variation
|
|
} else {
|
|
rto = info.srtt + info.variation
|
|
}
|
|
|
|
if rto > 10000 {
|
|
rto = 10000
|
|
}
|
|
info.rto = rto * 5 / 4
|
|
info.updatedTimestamp = current
|
|
}
|
|
|
|
func (info *RoundTripInfo) Timeout() uint32 {
|
|
info.RLock()
|
|
defer info.RUnlock()
|
|
|
|
return info.rto
|
|
}
|
|
|
|
func (info *RoundTripInfo) SmoothedTime() uint32 {
|
|
info.RLock()
|
|
defer info.RUnlock()
|
|
|
|
return info.srtt
|
|
}
|
|
|
|
type Updater struct {
|
|
interval int64
|
|
shouldContinue func() bool
|
|
shouldTerminate func() bool
|
|
updateFunc func()
|
|
notifier *semaphore.Instance
|
|
}
|
|
|
|
func NewUpdater(interval uint32, shouldContinue func() bool, shouldTerminate func() bool, updateFunc func()) *Updater {
|
|
u := &Updater{
|
|
interval: int64(time.Duration(interval) * time.Millisecond),
|
|
shouldContinue: shouldContinue,
|
|
shouldTerminate: shouldTerminate,
|
|
updateFunc: updateFunc,
|
|
notifier: semaphore.New(1),
|
|
}
|
|
return u
|
|
}
|
|
|
|
func (u *Updater) WakeUp() {
|
|
select {
|
|
case <-u.notifier.Wait():
|
|
go u.run()
|
|
default:
|
|
}
|
|
}
|
|
|
|
func (u *Updater) run() {
|
|
defer u.notifier.Signal()
|
|
|
|
if u.shouldTerminate() {
|
|
return
|
|
}
|
|
ticker := time.NewTicker(u.Interval())
|
|
for u.shouldContinue() {
|
|
u.updateFunc()
|
|
<-ticker.C
|
|
}
|
|
ticker.Stop()
|
|
}
|
|
|
|
func (u *Updater) Interval() time.Duration {
|
|
return time.Duration(atomic.LoadInt64(&u.interval))
|
|
}
|
|
|
|
func (u *Updater) SetInterval(d time.Duration) {
|
|
atomic.StoreInt64(&u.interval, int64(d))
|
|
}
|
|
|
|
type ConnMetadata struct {
|
|
LocalAddr net.Addr
|
|
RemoteAddr net.Addr
|
|
Conversation uint16
|
|
}
|
|
|
|
// Connection is a KCP connection over UDP.
|
|
type Connection struct {
|
|
meta ConnMetadata
|
|
closer io.Closer
|
|
rd time.Time
|
|
wd time.Time // write deadline
|
|
since int64
|
|
dataInput *signal.Notifier
|
|
dataOutput *signal.Notifier
|
|
Config *Config
|
|
|
|
state State
|
|
stateBeginTime uint32
|
|
lastIncomingTime uint32
|
|
lastPingTime uint32
|
|
|
|
mss uint32
|
|
roundTrip *RoundTripInfo
|
|
|
|
receivingWorker *ReceivingWorker
|
|
sendingWorker *SendingWorker
|
|
|
|
output SegmentWriter
|
|
|
|
dataUpdater *Updater
|
|
pingUpdater *Updater
|
|
}
|
|
|
|
// NewConnection create a new KCP connection between local and remote.
|
|
func NewConnection(meta ConnMetadata, writer PacketWriter, closer io.Closer, config *Config) *Connection {
|
|
newError("#", meta.Conversation, " creating connection to ", meta.RemoteAddr).WriteToLog()
|
|
|
|
conn := &Connection{
|
|
meta: meta,
|
|
closer: closer,
|
|
since: nowMillisec(),
|
|
dataInput: signal.NewNotifier(),
|
|
dataOutput: signal.NewNotifier(),
|
|
Config: config,
|
|
output: NewRetryableWriter(NewSegmentWriter(writer)),
|
|
mss: config.GetMTUValue() - uint32(writer.Overhead()) - DataSegmentOverhead,
|
|
roundTrip: &RoundTripInfo{
|
|
rto: 100,
|
|
minRtt: config.GetTTIValue(),
|
|
},
|
|
}
|
|
|
|
conn.receivingWorker = NewReceivingWorker(conn)
|
|
conn.sendingWorker = NewSendingWorker(conn)
|
|
|
|
isTerminating := func() bool {
|
|
return conn.State().Is(StateTerminating, StateTerminated)
|
|
}
|
|
isTerminated := func() bool {
|
|
return conn.State() == StateTerminated
|
|
}
|
|
conn.dataUpdater = NewUpdater(
|
|
config.GetTTIValue(),
|
|
func() bool {
|
|
return !isTerminating() && (conn.sendingWorker.UpdateNecessary() || conn.receivingWorker.UpdateNecessary())
|
|
},
|
|
isTerminating,
|
|
conn.updateTask)
|
|
conn.pingUpdater = NewUpdater(
|
|
5000, // 5 seconds
|
|
func() bool { return !isTerminated() },
|
|
isTerminated,
|
|
conn.updateTask)
|
|
conn.pingUpdater.WakeUp()
|
|
|
|
return conn
|
|
}
|
|
|
|
func (c *Connection) Elapsed() uint32 {
|
|
return uint32(nowMillisec() - c.since)
|
|
}
|
|
|
|
// ReadMultiBuffer implements buf.Reader.
|
|
func (c *Connection) ReadMultiBuffer() (buf.MultiBuffer, error) {
|
|
if c == nil {
|
|
return nil, io.EOF
|
|
}
|
|
|
|
for {
|
|
if c.State().Is(StateReadyToClose, StateTerminating, StateTerminated) {
|
|
return nil, io.EOF
|
|
}
|
|
mb := c.receivingWorker.ReadMultiBuffer()
|
|
if !mb.IsEmpty() {
|
|
c.dataUpdater.WakeUp()
|
|
return mb, nil
|
|
}
|
|
|
|
if c.State() == StatePeerTerminating {
|
|
return nil, io.EOF
|
|
}
|
|
|
|
if err := c.waitForDataInput(); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *Connection) waitForDataInput() error {
|
|
for i := 0; i < 16; i++ {
|
|
select {
|
|
case <-c.dataInput.Wait():
|
|
return nil
|
|
default:
|
|
runtime.Gosched()
|
|
}
|
|
}
|
|
|
|
duration := time.Second * 16
|
|
if !c.rd.IsZero() {
|
|
duration = time.Until(c.rd)
|
|
if duration < 0 {
|
|
return ErrIOTimeout
|
|
}
|
|
}
|
|
|
|
timeout := time.NewTimer(duration)
|
|
defer timeout.Stop()
|
|
|
|
select {
|
|
case <-c.dataInput.Wait():
|
|
case <-timeout.C:
|
|
if !c.rd.IsZero() && c.rd.Before(time.Now()) {
|
|
return ErrIOTimeout
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Read implements the Conn Read method.
|
|
func (c *Connection) Read(b []byte) (int, error) {
|
|
if c == nil {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
for {
|
|
if c.State().Is(StateReadyToClose, StateTerminating, StateTerminated) {
|
|
return 0, io.EOF
|
|
}
|
|
nBytes := c.receivingWorker.Read(b)
|
|
if nBytes > 0 {
|
|
c.dataUpdater.WakeUp()
|
|
return nBytes, nil
|
|
}
|
|
|
|
if err := c.waitForDataInput(); err != nil {
|
|
return 0, err
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *Connection) waitForDataOutput() error {
|
|
for i := 0; i < 16; i++ {
|
|
select {
|
|
case <-c.dataOutput.Wait():
|
|
return nil
|
|
default:
|
|
runtime.Gosched()
|
|
}
|
|
}
|
|
|
|
duration := time.Second * 16
|
|
if !c.wd.IsZero() {
|
|
duration = time.Until(c.wd)
|
|
if duration < 0 {
|
|
return ErrIOTimeout
|
|
}
|
|
}
|
|
|
|
timeout := time.NewTimer(duration)
|
|
defer timeout.Stop()
|
|
|
|
select {
|
|
case <-c.dataOutput.Wait():
|
|
case <-timeout.C:
|
|
if !c.wd.IsZero() && c.wd.Before(time.Now()) {
|
|
return ErrIOTimeout
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Write implements io.Writer.
|
|
func (c *Connection) Write(b []byte) (int, error) {
|
|
reader := bytes.NewReader(b)
|
|
if err := c.writeMultiBufferInternal(reader); err != nil {
|
|
return 0, err
|
|
}
|
|
return len(b), nil
|
|
}
|
|
|
|
// WriteMultiBuffer implements buf.Writer.
|
|
func (c *Connection) WriteMultiBuffer(mb buf.MultiBuffer) error {
|
|
reader := &buf.MultiBufferContainer{
|
|
MultiBuffer: mb,
|
|
}
|
|
defer reader.Close()
|
|
|
|
return c.writeMultiBufferInternal(reader)
|
|
}
|
|
|
|
func (c *Connection) writeMultiBufferInternal(reader io.Reader) error {
|
|
updatePending := false
|
|
defer func() {
|
|
if updatePending {
|
|
c.dataUpdater.WakeUp()
|
|
}
|
|
}()
|
|
|
|
var b *buf.Buffer
|
|
defer b.Release()
|
|
|
|
for {
|
|
for {
|
|
if c == nil || c.State() != StateActive {
|
|
return io.ErrClosedPipe
|
|
}
|
|
|
|
if b == nil {
|
|
b = buf.New()
|
|
_, err := b.ReadFrom(io.LimitReader(reader, int64(c.mss)))
|
|
if err != nil {
|
|
return nil
|
|
}
|
|
}
|
|
|
|
if !c.sendingWorker.Push(b) {
|
|
break
|
|
}
|
|
updatePending = true
|
|
b = nil
|
|
}
|
|
|
|
if updatePending {
|
|
c.dataUpdater.WakeUp()
|
|
updatePending = false
|
|
}
|
|
|
|
if err := c.waitForDataOutput(); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *Connection) SetState(state State) {
|
|
current := c.Elapsed()
|
|
atomic.StoreInt32((*int32)(&c.state), int32(state))
|
|
atomic.StoreUint32(&c.stateBeginTime, current)
|
|
newError("#", c.meta.Conversation, " entering state ", state, " at ", current).AtDebug().WriteToLog()
|
|
|
|
switch state {
|
|
case StateReadyToClose:
|
|
c.receivingWorker.CloseRead()
|
|
case StatePeerClosed:
|
|
c.sendingWorker.CloseWrite()
|
|
case StateTerminating:
|
|
c.receivingWorker.CloseRead()
|
|
c.sendingWorker.CloseWrite()
|
|
c.pingUpdater.SetInterval(time.Second)
|
|
case StatePeerTerminating:
|
|
c.sendingWorker.CloseWrite()
|
|
c.pingUpdater.SetInterval(time.Second)
|
|
case StateTerminated:
|
|
c.receivingWorker.CloseRead()
|
|
c.sendingWorker.CloseWrite()
|
|
c.pingUpdater.SetInterval(time.Second)
|
|
c.dataUpdater.WakeUp()
|
|
c.pingUpdater.WakeUp()
|
|
go c.Terminate()
|
|
}
|
|
}
|
|
|
|
// Close closes the connection.
|
|
func (c *Connection) Close() error {
|
|
if c == nil {
|
|
return ErrClosedConnection
|
|
}
|
|
|
|
c.dataInput.Signal()
|
|
c.dataOutput.Signal()
|
|
|
|
switch c.State() {
|
|
case StateReadyToClose, StateTerminating, StateTerminated:
|
|
return ErrClosedConnection
|
|
case StateActive:
|
|
c.SetState(StateReadyToClose)
|
|
case StatePeerClosed:
|
|
c.SetState(StateTerminating)
|
|
case StatePeerTerminating:
|
|
c.SetState(StateTerminated)
|
|
}
|
|
|
|
newError("#", c.meta.Conversation, " closing connection to ", c.meta.RemoteAddr).WriteToLog()
|
|
|
|
return nil
|
|
}
|
|
|
|
// LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
|
|
func (c *Connection) LocalAddr() net.Addr {
|
|
if c == nil {
|
|
return nil
|
|
}
|
|
return c.meta.LocalAddr
|
|
}
|
|
|
|
// RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
|
|
func (c *Connection) RemoteAddr() net.Addr {
|
|
if c == nil {
|
|
return nil
|
|
}
|
|
return c.meta.RemoteAddr
|
|
}
|
|
|
|
// SetDeadline sets the deadline associated with the listener. A zero time value disables the deadline.
|
|
func (c *Connection) SetDeadline(t time.Time) error {
|
|
if err := c.SetReadDeadline(t); err != nil {
|
|
return err
|
|
}
|
|
return c.SetWriteDeadline(t)
|
|
}
|
|
|
|
// SetReadDeadline implements the Conn SetReadDeadline method.
|
|
func (c *Connection) SetReadDeadline(t time.Time) error {
|
|
if c == nil || c.State() != StateActive {
|
|
return ErrClosedConnection
|
|
}
|
|
c.rd = t
|
|
return nil
|
|
}
|
|
|
|
// SetWriteDeadline implements the Conn SetWriteDeadline method.
|
|
func (c *Connection) SetWriteDeadline(t time.Time) error {
|
|
if c == nil || c.State() != StateActive {
|
|
return ErrClosedConnection
|
|
}
|
|
c.wd = t
|
|
return nil
|
|
}
|
|
|
|
// kcp update, input loop
|
|
func (c *Connection) updateTask() {
|
|
c.flush()
|
|
}
|
|
|
|
func (c *Connection) Terminate() {
|
|
if c == nil {
|
|
return
|
|
}
|
|
newError("#", c.meta.Conversation, " terminating connection to ", c.RemoteAddr()).WriteToLog()
|
|
|
|
// v.SetState(StateTerminated)
|
|
c.dataInput.Signal()
|
|
c.dataOutput.Signal()
|
|
|
|
c.closer.Close()
|
|
c.sendingWorker.Release()
|
|
c.receivingWorker.Release()
|
|
}
|
|
|
|
func (c *Connection) HandleOption(opt SegmentOption) {
|
|
if (opt & SegmentOptionClose) == SegmentOptionClose {
|
|
c.OnPeerClosed()
|
|
}
|
|
}
|
|
|
|
func (c *Connection) OnPeerClosed() {
|
|
switch c.State() {
|
|
case StateReadyToClose:
|
|
c.SetState(StateTerminating)
|
|
case StateActive:
|
|
c.SetState(StatePeerClosed)
|
|
}
|
|
}
|
|
|
|
// Input when you received a low level packet (eg. UDP packet), call it
|
|
func (c *Connection) Input(segments []Segment) {
|
|
current := c.Elapsed()
|
|
atomic.StoreUint32(&c.lastIncomingTime, current)
|
|
|
|
for _, seg := range segments {
|
|
if seg.Conversation() != c.meta.Conversation {
|
|
break
|
|
}
|
|
|
|
switch seg := seg.(type) {
|
|
case *DataSegment:
|
|
c.HandleOption(seg.Option)
|
|
c.receivingWorker.ProcessSegment(seg)
|
|
if c.receivingWorker.IsDataAvailable() {
|
|
c.dataInput.Signal()
|
|
}
|
|
c.dataUpdater.WakeUp()
|
|
case *AckSegment:
|
|
c.HandleOption(seg.Option)
|
|
c.sendingWorker.ProcessSegment(current, seg, c.roundTrip.Timeout())
|
|
c.dataOutput.Signal()
|
|
c.dataUpdater.WakeUp()
|
|
case *CmdOnlySegment:
|
|
c.HandleOption(seg.Option)
|
|
if seg.Command() == CommandTerminate {
|
|
switch c.State() {
|
|
case StateActive, StatePeerClosed:
|
|
c.SetState(StatePeerTerminating)
|
|
case StateReadyToClose:
|
|
c.SetState(StateTerminating)
|
|
case StateTerminating:
|
|
c.SetState(StateTerminated)
|
|
}
|
|
}
|
|
if seg.Option == SegmentOptionClose || seg.Command() == CommandTerminate {
|
|
c.dataInput.Signal()
|
|
c.dataOutput.Signal()
|
|
}
|
|
c.sendingWorker.ProcessReceivingNext(seg.ReceivingNext)
|
|
c.receivingWorker.ProcessSendingNext(seg.SendingNext)
|
|
c.roundTrip.UpdatePeerRTO(seg.PeerRTO, current)
|
|
seg.Release()
|
|
default:
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *Connection) flush() {
|
|
current := c.Elapsed()
|
|
|
|
if c.State() == StateTerminated {
|
|
return
|
|
}
|
|
if c.State() == StateActive && current-atomic.LoadUint32(&c.lastIncomingTime) >= 30000 {
|
|
c.Close()
|
|
}
|
|
if c.State() == StateReadyToClose && c.sendingWorker.IsEmpty() {
|
|
c.SetState(StateTerminating)
|
|
}
|
|
|
|
if c.State() == StateTerminating {
|
|
newError("#", c.meta.Conversation, " sending terminating cmd.").AtDebug().WriteToLog()
|
|
c.Ping(current, CommandTerminate)
|
|
|
|
if current-atomic.LoadUint32(&c.stateBeginTime) > 8000 {
|
|
c.SetState(StateTerminated)
|
|
}
|
|
return
|
|
}
|
|
if c.State() == StatePeerTerminating && current-atomic.LoadUint32(&c.stateBeginTime) > 4000 {
|
|
c.SetState(StateTerminating)
|
|
}
|
|
|
|
if c.State() == StateReadyToClose && current-atomic.LoadUint32(&c.stateBeginTime) > 15000 {
|
|
c.SetState(StateTerminating)
|
|
}
|
|
|
|
// flush acknowledges
|
|
c.receivingWorker.Flush(current)
|
|
c.sendingWorker.Flush(current)
|
|
|
|
if current-atomic.LoadUint32(&c.lastPingTime) >= 3000 {
|
|
c.Ping(current, CommandPing)
|
|
}
|
|
}
|
|
|
|
func (c *Connection) State() State {
|
|
return State(atomic.LoadInt32((*int32)(&c.state)))
|
|
}
|
|
|
|
func (c *Connection) Ping(current uint32, cmd Command) {
|
|
seg := NewCmdOnlySegment()
|
|
seg.Conv = c.meta.Conversation
|
|
seg.Cmd = cmd
|
|
seg.ReceivingNext = c.receivingWorker.NextNumber()
|
|
seg.SendingNext = c.sendingWorker.FirstUnacknowledged()
|
|
seg.PeerRTO = c.roundTrip.Timeout()
|
|
if c.State() == StateReadyToClose {
|
|
seg.Option = SegmentOptionClose
|
|
}
|
|
c.output.Write(seg)
|
|
atomic.StoreUint32(&c.lastPingTime, current)
|
|
seg.Release()
|
|
}
|