Drafted udp holepunching upsync pathway.

udp_server_prac/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"strings"
+)
+
+func main() {
+	conn, err := net.ListenUDP("udp", &net.UDPAddr{
+		Port: 3000,
+		IP:   net.ParseIP("127.0.0.1"),
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	defer conn.Close()
+	fmt.Printf("server listening %s\n", conn.LocalAddr().String())
+
+	for {
+		message := make([]byte, 2046)
+		rlen, remote, err := conn.ReadFromUDP(message[:])
+		if err != nil {
+			panic(err)
+		}
+
+		data := strings.TrimSpace(string(message[:rlen]))
+		fmt.Printf("received: %s from %s\n", data, remote)
+	}
+}