68 lines
1.5 KiB
Go
68 lines
1.5 KiB
Go
// Version: 2021.10
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// Build: go build -ldflags "-s -w"
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// Run: goudpserver -ip=0.0.0.0 -port=10003
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// Test: ncat -u localhost 10003
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package main
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import (
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"flag"
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"fmt"
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"net"
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"runtime"
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)
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func lstn(connection *net.UDPConn, alarm chan struct{}) {
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buffer := make([]byte, 1024)
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n, remoteAddr, err := 0, new(net.UDPAddr), error(nil)
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for err == nil {
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n, remoteAddr, err = connection.ReadFromUDP(buffer)
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if err != nil {
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fmt.Println("ReadUDP Error (", err.Error(), ")")
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} else {
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fmt.Println("From", remoteAddr, "-", string(buffer[:n]))
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}
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_, err = connection.WriteToUDP([]byte("OK\n"), remoteAddr)
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if err != nil {
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fmt.Println("WriteUDP Error (", err.Error(), ")")
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} else {
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fmt.Println("WriteUDP... OK")
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}
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}
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fmt.Println("Listener failed (", err, ")!")
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alarm <- struct{}{}
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}
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func main() {
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envFlag := runtime.GOMAXPROCS(runtime.NumCPU())
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if envFlag > -1 {
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fmt.Println("GOMAXPROCS =", runtime.NumCPU())
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} else {
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fmt.Println("GOMAXPROCS is default!")
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}
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argIP := flag.String("ip", "0.0.0.0", "Listen IP address")
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argPort := flag.Int("port", 10003, "Listen Port number")
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flag.Parse()
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fmt.Println("IP Address:", *argIP)
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fmt.Println("Port Number:", *argPort)
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addr := net.UDPAddr{
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Port: *argPort,
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IP: net.ParseIP(*argIP),
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}
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connection, err := net.ListenUDP("udp", &addr)
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if err != nil {
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panic(err)
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}
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alarm := make(chan struct{})
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fmt.Println("CPU Threads:", runtime.NumCPU())
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for i := 0; i < runtime.NumCPU(); i++ {
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go lstn(connection, alarm)
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}
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msg := <-alarm
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fmt.Println(msg)
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}
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