/
main.go
60 lines (48 loc) · 1.24 KB
/
main.go
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package main
import (
"bufio"
"log"
"net"
"os"
"time"
)
const network = "udp"
var serverHost = "127.0.0.1:5001"
func main() {
if len(os.Args) > 1 {
serverHost = os.Args[1]
}
conn, peer := establishConnection()
go func() {
b := make([]byte, 0xffff)
for {
n, _, _ := conn.ReadFromUDP(b)
if n > 0 {
log.Println("Peer:", string(b[:n]))
}
}
}()
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
msg := scanner.Text()
conn.WriteToUDP([]byte(msg), peer)
log.Println("Me:", msg)
}
}
func establishConnection() (*net.UDPConn, *net.UDPAddr) {
conn, _ := net.ListenUDP(network, nil)
// Write to server
serverAddr, _ := net.ResolveUDPAddr(network, serverHost)
conn.WriteToUDP([]byte{}, serverAddr)
// Listen for server response with peer's remote address
b := make([]byte, 128)
n, _, _ := conn.ReadFromUDP(b)
// fetch remote addr
peerAddr, _ := net.ResolveUDPAddr(network, string(b[:n]))
// send datagram to peer
for i := 0; i < 2; i++ {
time.Sleep(time.Millisecond * 70)
conn.WriteToUDP([]byte{}, peerAddr)
}
return conn, peerAddr
}