netbird/client/internal/dns/host_linux.go
2022-11-29 14:51:18 +01:00

88 lines
2.2 KiB
Go

package dns
import (
"bufio"
"fmt"
"github.com/netbirdio/netbird/iface"
log "github.com/sirupsen/logrus"
"os"
"strings"
)
const (
defaultResolvConfPath = "/etc/resolv.conf"
)
const (
netbirdManager osManagerType = iota
fileManager
networkManager
systemdManager
resolvConfManager
)
type osManagerType int
func newHostManager(wgInterface *iface.WGIface) (hostManager, error) {
osManager, err := getOSDNSManagerType()
if err != nil {
return nil, err
}
log.Debugf("discovered mode is: %d", osManager)
switch osManager {
case networkManager:
return newNetworkManagerDbusConfigurator(wgInterface)
case systemdManager:
return newSystemdDbusConfigurator(wgInterface)
case resolvConfManager:
return newResolvConfConfigurator(wgInterface)
default:
return newFileConfigurator()
}
}
func getOSDNSManagerType() (osManagerType, error) {
file, err := os.Open(defaultResolvConfPath)
if err != nil {
return 0, fmt.Errorf("unable to open %s for checking owner, got error: %s", defaultResolvConfPath, err)
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
text := scanner.Text()
if len(text) == 0 {
continue
}
if text[0] != '#' {
return fileManager, nil
}
if strings.Contains(text, fileGeneratedResolvConfContentHeader) {
return netbirdManager, nil
}
if strings.Contains(text, "NetworkManager") && isDbusListenerRunning(networkManagerDest, networkManagerDbusObjectNode) && isNetworkManagerSupported() {
log.Debugf("is nm running on supported v? %t", isNetworkManagerSupportedVersion())
return networkManager, nil
}
if strings.Contains(text, "systemd-resolved") && isDbusListenerRunning(systemdResolvedDest, systemdDbusObjectNode) {
return systemdManager, nil
}
if strings.Contains(text, "resolvconf") {
if isDbusListenerRunning(systemdResolvedDest, systemdDbusObjectNode) {
var value string
err = getSystemdDbusProperty(systemdDbusResolvConfModeProperty, &value)
if err == nil {
if value == systemdDbusResolvConfModeForeign {
return systemdManager, nil
}
}
log.Errorf("got an error while checking systemd resolv conf mode, error: %s", err)
}
return resolvConfManager, nil
}
}
return fileManager, nil
}