mirror of https://github.com/cbeuw/Cloak
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
143 lines
3.5 KiB
Go
143 lines
3.5 KiB
Go
package multiplex
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
"net"
|
|
"time"
|
|
|
|
log "github.com/sirupsen/logrus"
|
|
"sync"
|
|
"sync/atomic"
|
|
)
|
|
|
|
var ErrBrokenStream = errors.New("broken stream")
|
|
|
|
type Stream struct {
|
|
id uint32
|
|
|
|
session *Session
|
|
|
|
recvBuf recvBuffer
|
|
|
|
// atomic
|
|
nextSendSeq uint64
|
|
|
|
writingM sync.RWMutex
|
|
|
|
// atomic
|
|
closed uint32
|
|
|
|
obfsBuf []byte
|
|
|
|
// we assign each stream a fixed underlying TCP connection to utilise order guarantee provided by TCP itself
|
|
// so that frameSorter should have few to none ooo frames to deal with
|
|
// overall the streams in a session should be uniformly distributed across all connections
|
|
// This is not used in unordered connection mode
|
|
assignedConnId uint32
|
|
}
|
|
|
|
func makeStream(sesh *Session, id uint32, assignedConnId uint32) *Stream {
|
|
var recvBuf recvBuffer
|
|
if sesh.Unordered {
|
|
recvBuf = NewDatagramBuffer()
|
|
} else {
|
|
recvBuf = NewStreamBuffer()
|
|
}
|
|
|
|
stream := &Stream{
|
|
id: id,
|
|
session: sesh,
|
|
recvBuf: recvBuf,
|
|
obfsBuf: make([]byte, sesh.SendBufferSize),
|
|
assignedConnId: assignedConnId,
|
|
}
|
|
|
|
return stream
|
|
}
|
|
|
|
func (s *Stream) isClosed() bool { return atomic.LoadUint32(&s.closed) == 1 }
|
|
|
|
func (s *Stream) writeFrame(frame Frame) error {
|
|
toBeClosed, err := s.recvBuf.Write(frame)
|
|
if toBeClosed {
|
|
return s.passiveClose()
|
|
}
|
|
return err
|
|
}
|
|
|
|
// Read implements io.Read
|
|
func (s *Stream) Read(buf []byte) (n int, err error) {
|
|
//log.Tracef("attempting to read from stream %v", s.id)
|
|
if len(buf) == 0 {
|
|
return 0, nil
|
|
}
|
|
|
|
n, err = s.recvBuf.Read(buf)
|
|
if err == io.EOF {
|
|
return n, ErrBrokenStream
|
|
}
|
|
log.Tracef("%v read from stream %v with err %v", n, s.id, err)
|
|
return
|
|
|
|
}
|
|
|
|
// Write implements io.Write
|
|
func (s *Stream) Write(in []byte) (n int, err error) {
|
|
// RWMutex used here isn't really for RW.
|
|
// we use it to exploit the fact that RLock doesn't create contention.
|
|
// The use of RWMutex is so that the stream will not actively close
|
|
// in the middle of the execution of Write. This may cause the closing frame
|
|
// to be sent before the data frame and cause loss of packet.
|
|
//log.Tracef("attempting to write %v bytes to stream %v",len(in),s.id)
|
|
s.writingM.RLock()
|
|
defer s.writingM.RUnlock()
|
|
if s.isClosed() {
|
|
return 0, ErrBrokenStream
|
|
}
|
|
|
|
f := &Frame{
|
|
StreamID: s.id,
|
|
Seq: atomic.AddUint64(&s.nextSendSeq, 1) - 1,
|
|
Closing: C_NOOP,
|
|
Payload: in,
|
|
}
|
|
|
|
i, err := s.session.Obfs(f, s.obfsBuf)
|
|
if err != nil {
|
|
return i, err
|
|
}
|
|
n, err = s.session.sb.send(s.obfsBuf[:i], &s.assignedConnId)
|
|
log.Tracef("%v sent to remote through stream %v with err %v", len(in), s.id, err)
|
|
if err != nil {
|
|
if err == errBrokenSwitchboard {
|
|
s.session.SetTerminalMsg(err.Error())
|
|
s.session.passiveClose()
|
|
}
|
|
return
|
|
}
|
|
return len(in), nil
|
|
|
|
}
|
|
|
|
func (s *Stream) passiveClose() error {
|
|
return s.session.closeStream(s, false)
|
|
}
|
|
|
|
// active close. Close locally and tell the remote that this stream is being closed
|
|
func (s *Stream) Close() error {
|
|
return s.session.closeStream(s, true)
|
|
}
|
|
|
|
// the following functions are purely for implementing net.Conn interface.
|
|
// they are not used
|
|
var errNotImplemented = errors.New("Not implemented")
|
|
|
|
func (s *Stream) LocalAddr() net.Addr { return s.session.addrs.Load().([]net.Addr)[0] }
|
|
func (s *Stream) RemoteAddr() net.Addr { return s.session.addrs.Load().([]net.Addr)[1] }
|
|
|
|
// TODO: implement the following
|
|
func (s *Stream) SetDeadline(t time.Time) error { return errNotImplemented }
|
|
func (s *Stream) SetReadDeadline(t time.Time) error { return errNotImplemented }
|
|
func (s *Stream) SetWriteDeadline(t time.Time) error { return errNotImplemented }
|