ipsock を試した

ipsock.go

package main

import (
	"log"
	"net"
	"sync"
	"time"
)

func main() {
	srcaddr, err := net.ResolveIPAddr("ip4", "169.254.251.212")
	if err != nil {
		log.Panic(err)
	}
	destaddr, err := net.ResolveIPAddr("ip4", "169.254.22.60")
	if err != nil {
		log.Panic(err)
	}
	conn, err := net.DialIP("ip4:101", srcaddr, destaddr)
	if err != nil {
		log.Panic(err)
	}
	defer conn.Close()
	log.Println("hello world")

	lconn, err := net.ListenIP("ip4:101", destaddr)
	if err != nil {
		log.Panic(err)
	}

	var wg sync.WaitGroup

	log.Println("allocated")
	time.Sleep(10 * time.Second)
	log.Println("start")


	wg.Add(2)
	go func() {
		defer wg.Done()
		msg := []byte("hello world!!")
		if _, err := conn.Write(msg); err != nil {
			log.Panic("failed to write :", err)
		}
	}()
	go func() {
		defer wg.Done()
		var buf [1500]byte
		for {
			n, addr, err := lconn.ReadFromIP(buf[:])
			if err != nil {
				log.Panic("failed to read :", err)
			}
			log.Println("read from :", addr)
			if addr.String() == srcaddr.String() {
				log.Println("this is exact addr")
				log.Printf("msg :\"%s\"\n", string(buf[:n]))
				break
			}
		}
	}()

	wg.Wait()
}