init

network/udp/server.go

@@ -0,0 +1,115 @@
+package udp
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"runtime"
+	"sync"
+)
+
+type Server struct {
+	bindAddr     string
+	routingTable *RoutingTable
+
+	conn   *net.UDPConn
+	wg     sync.WaitGroup
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+func NewServer(bindAddr string) (*Server, error) {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	return &Server{
+		bindAddr: bindAddr,
+		ctx:      ctx,
+		cancel:   cancel,
+	}, nil
+}
+
+func (s *Server) run() error {
+	add, err := net.ResolveUDPAddr("udp", s.bindAddr)
+	if err != nil {
+		return fmt.Errorf("cannot resolve address: %w", err)
+	}
+
+	s.conn, err = net.ListenUDP("udp", add)
+	if err != nil {
+		return fmt.Errorf("cannot listen on address: %w", err)
+	}
+
+	s.conn.SetReadBuffer(8 * 1024 * 1024)
+	s.conn.SetWriteBuffer(8 * 1024 * 1024)
+	fmt.Println("Listening on", s.bindAddr)
+
+	for i := 0; i < runtime.NumCPU(); i++ {
+		s.wg.Add(1)
+		// todo : add so_reuseport option when on unix like system
+		go s.workerLoop(i)
+	}
+
+	return nil
+}
+
+func (s *Server) sendTo(data []byte, addr *net.UDPAddr) error {
+	if s.conn == nil {
+		return fmt.Errorf("server not started")
+	}
+
+	_, err := s.conn.WriteToUDP(data, addr)
+	return err
+}
+
+func (s *Server) workerLoop(id int) {
+	defer s.wg.Done()
+
+	buffer := make([]byte, 1500)
+	fmt.Println("Worker", id, "started")
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			fmt.Println("Worker", id, "stopped")
+			return
+		default:
+			size, addr, err := s.conn.ReadFromUDP(buffer)
+			if err != nil {
+				if s.ctx.Err() != nil {
+					return
+				}
+				if opErr, ok := err.(*net.OpError); ok && opErr.Temporary() {
+					continue
+				}
+				fmt.Printf("Error reading from UDP: %v\n", err)
+				continue
+			}
+
+			s.handlePacket(buffer[:size], addr)
+		}
+	}
+}
+
+func (s *Server) handlePacket(data []byte, addr *net.UDPAddr) {
+	pt := PacketType(data[0])
+	switch pt {
+	case PacketTypePing:
+		err := s.sendTo([]byte{byte(PacketTypePing)}, addr)
+		if err != nil {
+			return
+		}
+		return
+	case PacketTypeConnect:
+		return
+	case PacketTypeDisconnect:
+		return
+	case PacketTypeVoiceData:
+		// todo : déterminer le format du packet
+		//channelID := string(data[1:5])
+		return
+	default:
+		return
+
+	}
+
+}