syncthing/vendor/github.com/jackpal/gateway/gateway_windows.go
2016-04-13 18:50:40 +00:00

44 lines
1.2 KiB
Go

package gateway
import (
"bytes"
"io/ioutil"
"net"
"os/exec"
)
func DiscoverGateway() (ip net.IP, err error) {
routeCmd := exec.Command("route", "print", "0.0.0.0")
stdOut, err := routeCmd.StdoutPipe()
if err != nil {
return
}
if err = routeCmd.Start(); err != nil {
return
}
output, err := ioutil.ReadAll(stdOut)
if err != nil {
return
}
// Windows route output format is always like this:
// ===========================================================================
// Active Routes:
// Network Destination Netmask Gateway Interface Metric
// 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.100 20
// ===========================================================================
// I'm trying to pick the active route,
// then jump 2 lines and pick the third IP
// Not using regex because output is quite standard from Windows XP to 8 (NEEDS TESTING)
outputLines := bytes.Split(output, []byte("\n"))
for idx, line := range outputLines {
if bytes.Contains(line, []byte("Active Routes:")) {
ipFields := bytes.Fields(outputLines[idx+2])
ip = net.ParseIP(string(ipFields[2]))
break
}
}
err = routeCmd.Wait()
return
}