Fix: should keep alive in tcp relay

listener/tun/device/tun/tun_wireguard.go

@@ -20,7 +20,6 @@ type TUN struct {
 	mtu    uint32
 	name   string
 	offset int
-	buff   []byte
 }
 
 func Open(name string, mtu uint32) (_ device.Device, err error) {
@@ -43,7 +42,6 @@ func Open(name string, mtu uint32) (_ device.Device, err error) {
 		name:   name,
 		mtu:    mtu,
 		offset: offset,
-		buff:   make([]byte, offset+pool.RelayBufferSize),
 	}
 
 	forcedMTU := defaultMTU
@@ -71,14 +69,17 @@ func (t *TUN) Read(packet []byte) (int, error) {
 		return t.nt.Read(packet, t.offset)
 	}
 
-	n, err := t.nt.Read(t.buff, t.offset)
+	buff := pool.Get(t.offset + cap(packet))
+	defer pool.Put(buff)
+
+	n, err := t.nt.Read(buff, t.offset)
 	if err != nil {
 		return 0, err
 	}
 
-	_ = t.buff[:t.offset]
+	_ = buff[:t.offset]
 
-	copy(packet, t.buff[t.offset:t.offset+n])
+	copy(packet, buff[t.offset:t.offset+n])
 
 	return n, err
 }

listener/tun/ipstack/gvisor/handler.go

@@ -125,7 +125,10 @@ func (gh *GVHandler) HandleUDPConn(tunConn adapter.UDPConn) {
 				payload: payload,
 			}
 
-			gh.UDPIn <- inbound.NewPacket(target, gvPacket, C.TUN)
+			select {
+			case gh.UDPIn <- inbound.NewPacket(target, gvPacket, C.TUN):
+			default:
+			}
 		}
 	}()
 }

listener/tun/ipstack/system/mars/nat/tcp.go

@@ -32,8 +32,6 @@ func (t *TCP) Accept() (net.Conn, error) {
 		return nil, net.InvalidAddrError("unknown remote addr")
 	}
 
-	// _ = c.SetKeepAlive(false)
-
 	addition(c)
 
 	return &conn{

listener/tun/ipstack/system/stack.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net"
 	"net/netip"
+	"runtime"
 	"strconv"
 	"time"
 
@@ -182,13 +183,22 @@ func New(device device.Device, dnsHijack []netip.AddrPort, tunAddress netip.Pref
 				},
 			}
 
-			udpIn <- inbound.NewPacket(socks5.ParseAddrToSocksAddr(rAddr), pkt, C.TUN)
+			select {
+			case udpIn <- inbound.NewPacket(socks5.ParseAddrToSocksAddr(rAddr), pkt, C.TUN):
+			default:
+			}
 		}
 	}
 
 	go tcp()
-	go udp()
-	go udp()
+
+	numUDPWorkers := 4
+	if num := runtime.GOMAXPROCS(0); num > numUDPWorkers {
+		numUDPWorkers = num
+	}
+	for i := 0; i < numUDPWorkers; i++ {
+		go udp()
+	}
 
 	return &sysStack{stack: stack, device: device}, nil
 }