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Removing Windows Server support

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This commit is contained in:
Cuong Manh Le
2025-07-03 15:25:16 +07:00
committed by Cuong Manh Le
parent ba9057e466
commit 975b465e3e
14 changed files with 13 additions and 363 deletions
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cmd/cli/os_windows.go
-115
View File
@@ -1,16 +1,12 @@
package cli
import (
"bytes"
"errors"
"fmt"
"net"
"net/netip"
"os"
"os/exec"
"slices"
"strings"
"sync"
"golang.org/x/sys/windows"
"golang.org/x/sys/windows/registry"
@@ -25,11 +21,6 @@ const (
v6InterfaceKeyPathFormat = `SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\Interfaces\`
)
var (
setDNSOnce sync.Once
resetDNSOnce sync.Once
)
// setDnsIgnoreUnusableInterface likes setDNS, but return a nil error if the interface is not usable.
func setDnsIgnoreUnusableInterface(iface *net.Interface, nameservers []string) error {
return setDNS(iface, nameservers)
@@ -40,49 +31,7 @@ func setDNS(iface *net.Interface, nameservers []string) error {
if len(nameservers) == 0 {
return errors.New("empty DNS nameservers")
}
setDNSOnce.Do(func() {
// If there's a Dns server running, that means we are on AD with Dns feature enabled.
// Configuring the Dns server to forward queries to ctrld instead.
if hasLocalDnsServerRunning() {
mainLog.Load().Debug().Msg("Local DNS server detected, configuring forwarders")
file := ctrld.AbsHomeDir(windowsForwardersFilename)
mainLog.Load().Debug().Msgf("Using forwarders file: %s", file)
oldForwardersContent, err := os.ReadFile(file)
if err != nil {
mainLog.Load().Debug().Err(err).Msg("Could not read existing forwarders file")
} else {
mainLog.Load().Debug().Msgf("Existing forwarders content: %s", string(oldForwardersContent))
}
hasLocalIPv6Listener := needLocalIPv6Listener()
mainLog.Load().Debug().Bool("has_ipv6_listener", hasLocalIPv6Listener).Msg("IPv6 listener status")
forwarders := slices.DeleteFunc(slices.Clone(nameservers), func(s string) bool {
if !hasLocalIPv6Listener {
return false
}
return s == "::1"
})
mainLog.Load().Debug().Strs("forwarders", forwarders).Msg("Filtered forwarders list")
if err := os.WriteFile(file, []byte(strings.Join(forwarders, ",")), 0600); err != nil {
mainLog.Load().Warn().Err(err).Msg("could not save forwarders settings")
} else {
mainLog.Load().Debug().Msg("Successfully wrote new forwarders file")
}
oldForwarders := strings.Split(string(oldForwardersContent), ",")
mainLog.Load().Debug().Strs("old_forwarders", oldForwarders).Msg("Previous forwarders")
if err := addDnsServerForwarders(forwarders, oldForwarders); err != nil {
mainLog.Load().Warn().Err(err).Msg("could not set forwarders settings")
} else {
mainLog.Load().Debug().Msg("Successfully configured DNS server forwarders")
}
}
})
luid, err := winipcfg.LUIDFromIndex(uint32(iface.Index))
if err != nil {
return fmt.Errorf("setDNS: %w", err)
@@ -126,25 +75,7 @@ func resetDnsIgnoreUnusableInterface(iface *net.Interface) error {
return resetDNS(iface)
}
// TODO(cuonglm): should we use system API?
func resetDNS(iface *net.Interface) error {
resetDNSOnce.Do(func() {
// See corresponding comment in setDNS.
if hasLocalDnsServerRunning() {
file := ctrld.AbsHomeDir(windowsForwardersFilename)
content, err := os.ReadFile(file)
if err != nil {
mainLog.Load().Error().Err(err).Msg("could not read forwarders settings")
return
}
nameservers := strings.Split(string(content), ",")
if err := removeDnsServerForwarders(nameservers); err != nil {
mainLog.Load().Error().Err(err).Msg("could not remove forwarders settings")
return
}
}
})
luid, err := winipcfg.LUIDFromIndex(uint32(iface.Index))
if err != nil {
return fmt.Errorf("resetDNS: %w", err)
@@ -285,49 +216,3 @@ func parseDNSServers(val string) []string {
}
return servers
}
// addDnsServerForwarders adds given nameservers to DNS server forwarders list,
// and also removing old forwarders if provided.
func addDnsServerForwarders(nameservers, old []string) error {
newForwardersMap := make(map[string]struct{})
newForwarders := make([]string, len(nameservers))
for i := range nameservers {
newForwardersMap[nameservers[i]] = struct{}{}
newForwarders[i] = fmt.Sprintf("%q", nameservers[i])
}
oldForwarders := old[:0]
for _, fwd := range old {
if _, ok := newForwardersMap[fwd]; !ok {
oldForwarders = append(oldForwarders, fwd)
}
}
// NOTE: It is important to add new forwarder before removing old one.
// Testing on Windows Server 2022 shows that removing forwarder1
// then adding forwarder2 sometimes ends up adding both of them
// to the forwarders list.
cmd := fmt.Sprintf("Add-DnsServerForwarder -IPAddress %s", strings.Join(newForwarders, ","))
if len(oldForwarders) > 0 {
cmd = fmt.Sprintf("%s ; Remove-DnsServerForwarder -IPAddress %s -Force", cmd, strings.Join(oldForwarders, ","))
}
if out, err := powershell(cmd); err != nil {
return fmt.Errorf("%w: %s", err, string(out))
}
return nil
}
// removeDnsServerForwarders removes given nameservers from DNS server forwarders list.
func removeDnsServerForwarders(nameservers []string) error {
for _, ns := range nameservers {
cmd := fmt.Sprintf("Remove-DnsServerForwarder -IPAddress %s -Force", ns)
if out, err := powershell(cmd); err != nil {
return fmt.Errorf("%w: %s", err, string(out))
}
}
return nil
}
// powershell runs the given powershell command.
func powershell(cmd string) ([]byte, error) {
out, err := exec.Command("powershell", "-Command", cmd).CombinedOutput()
return bytes.TrimSpace(out), err
}