Files
tun2socks/tunnel/tcp.go
2021-02-11 13:55:53 +08:00

88 lines
2.0 KiB
Go
Executable File

package tunnel
import (
"io"
"net"
"strconv"
"sync"
"time"
"github.com/xjasonlyu/tun2socks/common/pool"
M "github.com/xjasonlyu/tun2socks/constant"
"github.com/xjasonlyu/tun2socks/core"
"github.com/xjasonlyu/tun2socks/log"
"github.com/xjasonlyu/tun2socks/proxy"
"github.com/xjasonlyu/tun2socks/tunnel/statistic"
)
const (
tcpWaitTimeout = 5 * time.Second
)
func newTCPTracker(conn net.Conn, metadata *M.Metadata) net.Conn {
return statistic.NewTCPTracker(conn, metadata, statistic.DefaultManager)
}
func handleTCP(localConn core.TCPConn) {
defer localConn.Close()
id := localConn.ID()
metadata := &M.Metadata{
Net: M.TCP,
SrcIP: net.IP(id.RemoteAddress),
SrcPort: id.RemotePort,
DstIP: net.IP(id.LocalAddress),
DstPort: id.LocalPort,
}
targetConn, err := proxy.Dial(metadata)
if err != nil {
log.Warnf("[TCP] dial %s error: %v", metadata.DestinationAddress(), err)
return
}
if dialerAddr, ok := targetConn.LocalAddr().(*net.TCPAddr); ok {
metadata.MidIP = dialerAddr.IP
metadata.MidPort = uint16(dialerAddr.Port)
} else { /* fallback */
ip, p, _ := net.SplitHostPort(targetConn.LocalAddr().String())
port, _ := strconv.ParseUint(p, 10, 16)
metadata.MidIP = net.ParseIP(ip)
metadata.MidPort = uint16(port)
}
targetConn = newTCPTracker(targetConn, metadata)
defer targetConn.Close()
log.Infof("[TCP] %s <-> %s", metadata.SourceAddress(), metadata.DestinationAddress())
relay(localConn, targetConn) /* relay connections */
}
// relay copies between left and right bidirectionally.
func relay(left, right net.Conn) {
wg := sync.WaitGroup{}
wg.Add(2)
go func() {
defer wg.Done()
_ = copyBuffer(right, left) /* ignore error */
right.SetReadDeadline(time.Now().Add(tcpWaitTimeout))
}()
go func() {
defer wg.Done()
_ = copyBuffer(left, right) /* ignore error */
left.SetReadDeadline(time.Now().Add(tcpWaitTimeout))
}()
wg.Wait()
}
func copyBuffer(dst io.Writer, src io.Reader) error {
buf := pool.Get(pool.RelayBufferSize)
defer pool.Put(buf)
_, err := io.CopyBuffer(dst, src, buf)
return err
}