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
|
package engine
import (
"fmt"
"net"
"vpnem/internal/config"
)
var localProxyPortCandidates = []int{config.LocalProxyPort, 10808, 10880, 18080, 20800}
func ResolveLocalProxyPort() (int, error) {
for _, port := range localProxyPortCandidates {
if localProxyPortAvailable(port) {
return port, nil
}
}
listener, err := net.Listen("tcp", net.JoinHostPort(config.LocalProxyHost, "0"))
if err != nil {
return 0, err
}
defer listener.Close()
addr, ok := listener.Addr().(*net.TCPAddr)
if !ok {
return 0, fmt.Errorf("unexpected listener addr type %T", listener.Addr())
}
return addr.Port, nil
}
func localProxyPortAvailable(port int) bool {
listener, err := net.Listen("tcp", net.JoinHostPort(config.LocalProxyHost, fmt.Sprintf("%d", port)))
if err != nil {
return false
}
_ = listener.Close()
return true
}
|