github.com/xraypb/Xray-core@v1.8.1/transport/internet/kcp/dialer.go (about)

     1  package kcp
     2  
     3  import (
     4  	"context"
     5  	"io"
     6  	"sync/atomic"
     7  
     8  	"github.com/xraypb/Xray-core/common"
     9  	"github.com/xraypb/Xray-core/common/buf"
    10  	"github.com/xraypb/Xray-core/common/dice"
    11  	"github.com/xraypb/Xray-core/common/net"
    12  	"github.com/xraypb/Xray-core/transport/internet"
    13  	"github.com/xraypb/Xray-core/transport/internet/stat"
    14  	"github.com/xraypb/Xray-core/transport/internet/tls"
    15  )
    16  
    17  var globalConv = uint32(dice.RollUint16())
    18  
    19  func fetchInput(_ context.Context, input io.Reader, reader PacketReader, conn *Connection) {
    20  	cache := make(chan *buf.Buffer, 1024)
    21  	go func() {
    22  		for {
    23  			payload := buf.New()
    24  			if _, err := payload.ReadFrom(input); err != nil {
    25  				payload.Release()
    26  				close(cache)
    27  				return
    28  			}
    29  			select {
    30  			case cache <- payload:
    31  			default:
    32  				payload.Release()
    33  			}
    34  		}
    35  	}()
    36  
    37  	for payload := range cache {
    38  		segments := reader.Read(payload.Bytes())
    39  		payload.Release()
    40  		if len(segments) > 0 {
    41  			conn.Input(segments)
    42  		}
    43  	}
    44  }
    45  
    46  // DialKCP dials a new KCP connections to the specific destination.
    47  func DialKCP(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (stat.Connection, error) {
    48  	dest.Network = net.Network_UDP
    49  	newError("dialing mKCP to ", dest).WriteToLog()
    50  
    51  	rawConn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
    52  	if err != nil {
    53  		return nil, newError("failed to dial to dest: ", err).AtWarning().Base(err)
    54  	}
    55  
    56  	kcpSettings := streamSettings.ProtocolSettings.(*Config)
    57  
    58  	header, err := kcpSettings.GetPackerHeader()
    59  	if err != nil {
    60  		return nil, newError("failed to create packet header").Base(err)
    61  	}
    62  	security, err := kcpSettings.GetSecurity()
    63  	if err != nil {
    64  		return nil, newError("failed to create security").Base(err)
    65  	}
    66  	reader := &KCPPacketReader{
    67  		Header:   header,
    68  		Security: security,
    69  	}
    70  	writer := &KCPPacketWriter{
    71  		Header:   header,
    72  		Security: security,
    73  		Writer:   rawConn,
    74  	}
    75  
    76  	conv := uint16(atomic.AddUint32(&globalConv, 1))
    77  	session := NewConnection(ConnMetadata{
    78  		LocalAddr:    rawConn.LocalAddr(),
    79  		RemoteAddr:   rawConn.RemoteAddr(),
    80  		Conversation: conv,
    81  	}, writer, rawConn, kcpSettings)
    82  
    83  	go fetchInput(ctx, rawConn, reader, session)
    84  
    85  	var iConn stat.Connection = session
    86  
    87  	if config := tls.ConfigFromStreamSettings(streamSettings); config != nil {
    88  		iConn = tls.Client(iConn, config.GetTLSConfig(tls.WithDestination(dest)))
    89  	}
    90  
    91  	return iConn, nil
    92  }
    93  
    94  func init() {
    95  	common.Must(internet.RegisterTransportDialer(protocolName, DialKCP))
    96  }