92 lines
1.8 KiB
Go
92 lines
1.8 KiB
Go
package main
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import (
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"net"
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"os"
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"fmt"
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"strings"
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)
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func main() {
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if len(os.Args) <= 1 {
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fmt.Fprintf(os.Stderr, "Usage: %s <local node port> <remote node port>\n", os.Args[0])
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os.Exit(1)
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}
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// Configure this local node's listening port.
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service := ":" + os.Args[1]
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tcpAddr, err := net.ResolveTCPAddr("tcp4", service)
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checkError(err)
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listener, err := net.ListenTCP("tcp", tcpAddr)
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checkError(err)
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// If a remote peer's port is specified, we want to connect and message it
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if len(os.Args) == 3 {
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fmt.Println("Found a remote peer")
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remote := ":" + os.Args[2]
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tcpRemote, err := net.ResolveTCPAddr("tcp4", remote)
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checkError(err)
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peerconn, err := net.DialTCP("tcp4", nil, tcpRemote)
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checkError(err)
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_, err = peerconn.Write([]byte("Hello from " + os.Args[1]))
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checkError(err)
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var buf [512]byte
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n, err := peerconn.Read(buf[0:])
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checkError(err)
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result := string(buf[0:n])
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fmt.Println(string(result))
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}
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fmt.Printf("(%s) Waiting for peer connections...\n", os.Args[1])
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for {
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conn, err := listener.Accept()
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if err != nil {
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continue
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}
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handleConnection(conn)
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}
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}
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func handleConnection(conn net.Conn) {
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// close connection on exit
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defer conn.Close()
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var buf [512]byte
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for {
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// read up to 512 bytes
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n, err := conn.Read(buf[0:])
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if err != nil {
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return
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}
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message := string(buf[0:n])
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fmt.Println(message)
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tokens := strings.Split(message, " ")
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if tokens[0] != "" {
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response := "Hi " + tokens[2] + ", from " + os.Args[1]
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// write the n bytes read
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_, err2 := conn.Write([]byte(response))
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if err2 != nil {
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return
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}
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}
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}
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}
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func checkError(err error) {
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if err != nil {
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fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
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os.Exit(1)
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}
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}
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