how to use udp.packetaddr

[rurirei]

as i know udp.CopyPacketConn (request part as a example) reads from *packetConnectionAdaptor, and writes to *packetConnWrapper, in which *packetConnWrapper extracts the dst addr to write here, while *packetConnectionAdaptor already extracted the dst packet header, does the extraction again. what i'm missing? sorry but @AkinoKaede .

v2ray-core/common/net/packetaddr/connection_adaptor.go

Line 75 in aa32199

w, addr, err = ExtractAddressFromPacket(buf.FromBytes(p[:n]))

v2ray-core/common/net/packetaddr/connection_adaptor.go

Line 154 in aa32199

data, addr, err := ExtractAddressFromPacket(buf.FromBytes(p))

v2ray-core/proxy/shadowsocks/client.go

Lines 104 to 118 in aa32199

	if packetConn, err := packetaddr.ToPacketAddrConn(link, destination); err == nil {
	requestDone := func() error {
	protocolWriter := &UDPWriter{
	Writer: conn,
	Request: request,
	}
	return udp.CopyPacketConn(protocolWriter, packetConn, udp.UpdateActivity(timer))
	}
	responseDone := func() error {
	protocolReader := &UDPReader{
	Reader: conn,
	User: user,
	}
	return udp.CopyPacketConn(packetConn, protocolReader, udp.UpdateActivity(timer))
	}