/
main.go
90 lines (83 loc) · 1.78 KB
/
main.go
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// Echosvr is a simple TCP echo server
//
// It prints its listen address on stdout
//
// 127.0.0.1:xxxxx
// A test should wait for this line, parse it
// and may then attempt to connect.
package main
import (
"bufio"
"fmt"
"io"
"log"
"net"
"os"
"strings"
"time"
)
func main() {
// Start TCP server
listener, err := net.Listen("tcp", ":")
if err != nil {
panic(err)
}
defer listener.Close()
// use the same port for UDP
_, port, err := net.SplitHostPort(listener.Addr().String())
if err != nil {
panic(err)
}
fmt.Printf("127.0.0.1:%s\n", port)
go func() {
for {
conn, err := listener.Accept()
if err != nil {
panic(err)
}
go handleConnection(conn)
}
}()
// Start UDP server
addr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%s", port))
if err != nil {
log.Printf("Error from net.ResolveUDPAddr(): %s", err)
return
}
sock, err := net.ListenUDP("udp", addr)
if err != nil {
log.Printf("Error from ListenUDP(): %s", err)
return
}
defer sock.Close()
buffer := make([]byte, 1024)
for {
n, addr, err := sock.ReadFrom(buffer)
if err != nil {
log.Printf("Error from ReadFrom(): %s", err)
return
}
sock.SetWriteDeadline(time.Now().Add(1 * time.Minute))
_, err = sock.WriteTo(buffer[0:n], addr)
if err != nil {
return
}
}
}
func handleConnection(conn net.Conn) {
conn.SetReadDeadline(time.Now().Add(1 * time.Minute))
content, err := bufio.NewReader(conn).ReadString('\n')
if err != nil && err != io.EOF {
fmt.Fprint(os.Stderr, err.Error())
return
}
conn.SetWriteDeadline(time.Now().Add(1 * time.Minute))
if _, err = conn.Write([]byte(strings.TrimSuffix(content, "\n"))); err != nil {
fmt.Fprint(os.Stderr, err.Error())
return
}
if err = conn.Close(); err != nil {
fmt.Fprint(os.Stderr, err.Error())
return
}
}