net/dns: fix staticheck.

Signed-off-by: David Anderson <danderson@tailscale.com>
This commit is contained in:
David Anderson 2021-04-13 17:28:37 -07:00
parent d6bb11b5bf
commit 84bd50329a
2 changed files with 0 additions and 75 deletions

View File

@ -9,11 +9,8 @@
package dns
import (
"bufio"
"bytes"
"context"
"fmt"
"os"
"sort"
"time"
@ -29,46 +26,6 @@
lowerPriority = int32(200) // lower than all builtin auto priorities
)
// isNMActive determines if NetworkManager is currently managing system DNS settings.
func isNMActive() bool {
ctx, cancel := context.WithTimeout(context.Background(), reconfigTimeout)
defer cancel()
conn, err := dbus.SystemBus()
if err != nil {
// Probably no DBus on this system. Either way, we can't
// control NM without DBus.
return false
}
// Try to ping NetworkManager's DnsManager object. If it responds,
// NM is running and we're allowed to touch it.
nm := conn.Object("org.freedesktop.NetworkManager", dbus.ObjectPath("/org/freedesktop/NetworkManager/DnsManager"))
call := nm.CallWithContext(ctx, "org.freedesktop.DBus.Peer.Ping", 0)
if call.Err != nil {
return false
}
f, err := os.Open("/etc/resolv.conf")
if err != nil {
return false
}
defer f.Close()
scanner := bufio.NewScanner(f)
for scanner.Scan() {
line := scanner.Bytes()
// Look for the word "NetworkManager" until comments end.
if len(line) > 0 && line[0] != '#' {
return false
}
if bytes.Contains(line, []byte("NetworkManager")) {
return true
}
}
return false
}
// nmManager uses the NetworkManager DBus API.
type nmManager struct {
interfaceName string

View File

@ -5,43 +5,11 @@
package dns
import (
"bufio"
"bytes"
"os"
"os/exec"
"tailscale.com/types/logger"
)
// isResolvconfActive indicates whether the system appears to be using resolvconf.
// If this is true, then directManager should be avoided:
// resolvconf has exclusive ownership of /etc/resolv.conf.
func isResolvconfActive() bool {
_, err := exec.LookPath("resolvconf")
if err != nil {
return false
}
f, err := os.Open("/etc/resolv.conf")
if err != nil {
return false
}
defer f.Close()
scanner := bufio.NewScanner(f)
for scanner.Scan() {
line := scanner.Bytes()
// Look for the word "resolvconf" until comments end.
if len(line) > 0 && line[0] != '#' {
return false
}
if bytes.Contains(line, []byte("resolvconf")) {
return true
}
}
return false
}
func newResolvconfManager(logf logger.Logf) (OSConfigurator, error) {
_, err := exec.Command("resolvconf", "--version").CombinedOutput()
if err != nil {