kubenetworks/kubevpn

//go:build windows

package dns

import (
    "context"
    "fmt"
    "net"
    "net/netip"
    "os/exec"

    log "github.com/sirupsen/logrus"
    "golang.org/x/sys/windows"
    "golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
    "k8s.io/apimachinery/pkg/util/sets"
)

func (c *Config) SetupDNS(ctx context.Context) error {
    clientConfig := c.Config
    tunName := c.TunName

    tun, err := net.InterfaceByName(tunName)
    if err != nil {
        return err
    }
    luid, err := winipcfg.LUIDFromIndex(uint32(tun.Index))
    if err != nil {
        return err
    }
    var servers []netip.Addr
    for _, s := range clientConfig.Servers {
        var addr netip.Addr
        addr, err = netip.ParseAddr(s)
        if err != nil {
            log.Errorf("Parse %s failed: %s", s, err)
            return err
        }
        servers = append(servers, addr.Unmap())
    }
    err = luid.SetDNS(windows.AF_INET, servers, clientConfig.Search)
    if err != nil {
        log.Errorf("Set DNS failed: %s", err)
        return err
    }
    err = luid.SetDNS(windows.AF_INET6, servers, clientConfig.Search)
    if err != nil {
        log.Errorf("Set DNS failed: %s", err)
        return err
    }
    //_ = updateNicMetric(tunName)
    //_ = addNicSuffixSearchList(clientConfig.Search)
    return nil
}

func (c *Config) CancelDNS() {
    c.removeHosts(sets.New[Entry]().Insert(c.Hosts...).UnsortedList())
    tun, err := net.InterfaceByName(c.TunName)
    if err != nil {
        return
    }
    luid, err := winipcfg.LUIDFromIndex(uint32(tun.Index))
    if err != nil {
        return
    }
    _ = luid.FlushDNS(windows.AF_INET)
    _ = luid.FlushDNS(windows.AF_INET6)
    _ = luid.FlushRoutes(windows.AF_INET)
    _ = luid.FlushRoutes(windows.AF_INET6)
}

func updateNicMetric(name string) error {
    cmd := exec.Command("PowerShell", []string{
        "Set-NetIPInterface",
        "-InterfaceAlias",
        fmt.Sprintf("\"%s\"", name),
        "-InterfaceMetric",
        "1",
    }...)
    out, err := cmd.CombinedOutput()
    if err != nil {
        log.Warnf("Failed to update nic metrics, error: %v, output: %s, command: %v", err, string(out), cmd.Args)
    }
    return err
}

// @see https://docs.microsoft.com/en-us/powershell/module/dnsclient/set-dnsclientglobalsetting?view=windowsserver2019-ps#example-1--set-the-dns-suffix-search-list
func addNicSuffixSearchList(search []string) error {
    cmd := exec.Command("PowerShell", []string{
        "Set-DnsClientGlobalSetting",
        "-SuffixSearchList",
        fmt.Sprintf("@(\"%s\", \"%s\", \"%s\")", search[0], search[1], search[2]),
    }...)
    output, err := cmd.CombinedOutput()
    log.Debugln(cmd.Args)
    if err != nil {
        log.Warnf("Failed to set DNS suffix search list, err: %v, output: %s, command: %v", err, string(output), cmd.Args)
    }
    return err
}

func GetHostFile() string {
    //return "/windows/system32/drivers/etc/hosts"
    return "C:\\Windows\\System32\\drivers\\etc\\hosts"
}