1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
// 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.Fatalf("Error from net.ResolveUDPAddr(): %s", err)
}
sock, err := net.ListenUDP("udp", addr)
if err != nil {
log.Fatalf("Error from ListenUDP(): %s", err)
}
defer sock.Close()
buffer := make([]byte, 1024)
for {
n, addr, err := sock.ReadFrom(buffer)
if err != nil {
log.Fatalf("Error from ReadFrom(): %s", err)
}
sock.SetWriteDeadline(time.Now().Add(1 * time.Minute))
n, 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
}
}
|
