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package main
import (
"fmt"
"net"
)
func main() {
udpAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:2053")
if err != nil {
fmt.Println("Failed to resolve UDP address:", err)
return
}
udpConn, err := net.ListenUDP("udp", udpAddr)
if err != nil {
fmt.Println("Failed to bind to address:", err)
return
}
defer udpConn.Close()
buf := make([]byte, 512)
for {
size, source, err := udpConn.ReadFromUDP(buf)
if err != nil {
fmt.Println("Error receiving data:", err)
break
}
receivedData := string(buf[:size])
fmt.Printf("Received %d bytes from %s: %s\n", size, source, receivedData)
response := make([]byte, 12)
copy(response, buf[:12])
response[2] = flipIndicator(response[2])
_, err = udpConn.WriteToUDP(response, source)
if err != nil {
fmt.Println("Failed to send response:", err)
}
}
}
func flipIndicator(b byte) byte {
return b | 0b10000000
}
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