Implementation read waiter for socks5 UDP and UoT

protocol/socks/packet_wait.go

@@ -0,0 +1,48 @@
+package socks
+
+import (
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+var _ N.PacketReadWaitCreator = (*AssociatePacketConn)(nil)
+
+func (c *AssociatePacketConn) CreateReadWaiter() (N.PacketReadWaiter, bool) {
+	readWaiter, isReadWaiter := bufio.CreatePacketReadWaiter(c.NetPacketConn)
+	if !isReadWaiter {
+		return nil, false
+	}
+	return &AssociatePacketReadWaiter{c, readWaiter}, true
+}
+
+var _ N.PacketReadWaiter = (*AssociatePacketReadWaiter)(nil)
+
+type AssociatePacketReadWaiter struct {
+	conn       *AssociatePacketConn
+	readWaiter N.PacketReadWaiter
+}
+
+func (w *AssociatePacketReadWaiter) InitializeReadWaiter(newBuffer func() *buf.Buffer) {
+	w.readWaiter.InitializeReadWaiter(newBuffer)
+}
+
+func (w *AssociatePacketReadWaiter) WaitReadPacket() (buffer *buf.Buffer, destination M.Socksaddr, err error) {
+	buffer, destination, err = w.readWaiter.WaitReadPacket()
+	if err != nil {
+		return
+	}
+	if buffer.Len() < 3 {
+		buffer.Release()
+		return nil, M.Socksaddr{}, ErrInvalidPacket
+	}
+	w.conn.remoteAddr = destination
+	buffer.Advance(3)
+	destination, err = M.SocksaddrSerializer.ReadAddrPort(buffer)
+	if err != nil {
+		buffer.Release()
+		return nil, M.Socksaddr{}, err
+	}
+	return
+}