github.com/v2fly/v2ray-core/v4@v4.45.2/transport/internet/kcp/dialer.go (about)

     1  //go:build !confonly
     2  // +build !confonly
     3  
     4  package kcp
     5  
     6  import (
     7  	"context"
     8  	"io"
     9  	"sync/atomic"
    10  
    11  	"github.com/v2fly/v2ray-core/v4/common"
    12  	"github.com/v2fly/v2ray-core/v4/common/buf"
    13  	"github.com/v2fly/v2ray-core/v4/common/dice"
    14  	"github.com/v2fly/v2ray-core/v4/common/net"
    15  	"github.com/v2fly/v2ray-core/v4/transport/internet"
    16  	"github.com/v2fly/v2ray-core/v4/transport/internet/tls"
    17  )
    18  
    19  var globalConv = uint32(dice.RollUint16())
    20  
    21  func fetchInput(_ context.Context, input io.Reader, reader PacketReader, conn *Connection) {
    22  	cache := make(chan *buf.Buffer, 1024)
    23  	go func() {
    24  		for {
    25  			payload := buf.New()
    26  			if _, err := payload.ReadFrom(input); err != nil {
    27  				payload.Release()
    28  				close(cache)
    29  				return
    30  			}
    31  			select {
    32  			case cache <- payload:
    33  			default:
    34  				payload.Release()
    35  			}
    36  		}
    37  	}()
    38  
    39  	for payload := range cache {
    40  		segments := reader.Read(payload.Bytes())
    41  		payload.Release()
    42  		if len(segments) > 0 {
    43  			conn.Input(segments)
    44  		}
    45  	}
    46  }
    47  
    48  // DialKCP dials a new KCP connections to the specific destination.
    49  func DialKCP(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (internet.Connection, error) {
    50  	dest.Network = net.Network_UDP
    51  	newError("dialing mKCP to ", dest).WriteToLog()
    52  
    53  	rawConn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
    54  	if err != nil {
    55  		return nil, newError("failed to dial to dest: ", err).AtWarning().Base(err)
    56  	}
    57  
    58  	kcpSettings := streamSettings.ProtocolSettings.(*Config)
    59  
    60  	header, err := kcpSettings.GetPackerHeader()
    61  	if err != nil {
    62  		return nil, newError("failed to create packet header").Base(err)
    63  	}
    64  	security, err := kcpSettings.GetSecurity()
    65  	if err != nil {
    66  		return nil, newError("failed to create security").Base(err)
    67  	}
    68  	reader := &KCPPacketReader{
    69  		Header:   header,
    70  		Security: security,
    71  	}
    72  	writer := &KCPPacketWriter{
    73  		Header:   header,
    74  		Security: security,
    75  		Writer:   rawConn,
    76  	}
    77  
    78  	conv := uint16(atomic.AddUint32(&globalConv, 1))
    79  	session := NewConnection(ConnMetadata{
    80  		LocalAddr:    rawConn.LocalAddr(),
    81  		RemoteAddr:   rawConn.RemoteAddr(),
    82  		Conversation: conv,
    83  	}, writer, rawConn, kcpSettings)
    84  
    85  	go fetchInput(ctx, rawConn, reader, session)
    86  
    87  	var iConn internet.Connection = session
    88  
    89  	if config := tls.ConfigFromStreamSettings(streamSettings); config != nil {
    90  		iConn = tls.Client(iConn, config.GetTLSConfig(tls.WithDestination(dest)))
    91  	}
    92  
    93  	return iConn, nil
    94  }
    95  
    96  func init() {
    97  	common.Must(internet.RegisterTransportDialer(protocolName, DialKCP))
    98  }