clash/tunnel/connection.go

89 lines
1.9 KiB
Go

package tunnel
import (
"errors"
"io"
"net"
"time"
N "github.com/Dreamacro/clash/common/net"
"github.com/Dreamacro/clash/common/pool"
"github.com/Dreamacro/clash/component/resolver"
C "github.com/Dreamacro/clash/constant"
)
func handleUDPToRemote(packet C.UDPPacket, pc C.PacketConn, metadata *C.Metadata) error {
defer packet.Drop()
// local resolve UDP dns
if !metadata.Resolved() {
ip, err := resolver.ResolveIP(metadata.Host)
if err != nil {
return err
}
metadata.DstIP = ip
}
addr := metadata.UDPAddr()
if addr == nil {
return errors.New("udp addr invalid")
}
if _, err := pc.WriteTo(packet.Data(), addr); err != nil {
return err
}
// reset timeout
pc.SetReadDeadline(time.Now().Add(udpTimeout))
return nil
}
func handleUDPToLocal(packet C.UDPPacket, pc net.PacketConn, key string, fAddr net.Addr) {
buf := pool.Get(pool.RelayBufferSize)
defer pool.Put(buf)
defer natTable.Delete(key)
defer pc.Close()
for {
pc.SetReadDeadline(time.Now().Add(udpTimeout))
n, from, err := pc.ReadFrom(buf)
if err != nil {
return
}
if fAddr != nil {
from = fAddr
}
_, err = packet.WriteBack(buf[:n], from)
if err != nil {
return
}
}
}
func handleSocket(ctx C.ConnContext, outbound net.Conn) {
relay(ctx.Conn(), outbound)
}
// relay copies between left and right bidirectionally.
func relay(leftConn, rightConn net.Conn) {
ch := make(chan error)
go func() {
buf := pool.Get(pool.RelayBufferSize)
// Wrapping to avoid using *net.TCPConn.(ReadFrom)
// See also https://github.com/Dreamacro/clash/pull/1209
_, err := io.CopyBuffer(N.WriteOnlyWriter{Writer: leftConn}, N.ReadOnlyReader{Reader: rightConn}, buf)
pool.Put(buf)
leftConn.SetReadDeadline(time.Now())
ch <- err
}()
buf := pool.Get(pool.RelayBufferSize)
io.CopyBuffer(N.WriteOnlyWriter{Writer: rightConn}, N.ReadOnlyReader{Reader: leftConn}, buf)
pool.Put(buf)
rightConn.SetReadDeadline(time.Now())
<-ch
}