chore: support IN-PORT rule

listener/tproxy/packet.go

@@ -7,6 +7,7 @@ import (
 )
 
 type packet struct {
+	pc    net.PacketConn
 	lAddr *net.UDPAddr
 	buf   []byte
 }
@@ -35,3 +36,7 @@ func (c *packet) LocalAddr() net.Addr {
 func (c *packet) Drop() {
 	pool.Put(c.buf)
 }
+
+func (c *packet) InAddr() net.Addr {
+	return c.pc.LocalAddr()
+}

listener/tproxy/udp.go

@@ -81,6 +81,7 @@ func NewUDP(addr string, in chan<- *inbound.PacketAdapter) (*UDPListener, error)
 func handlePacketConn(pc net.PacketConn, in chan<- *inbound.PacketAdapter, buf []byte, lAddr *net.UDPAddr, rAddr *net.UDPAddr) {
 	target := socks5.ParseAddrToSocksAddr(rAddr)
 	pkt := &packet{
+		pc:    pc,
 		lAddr: lAddr,
 		buf:   buf,
 	}