cmd/cli: add split route AD domain on Windows

cmd/cli/ad_others.go

@@ -0,0 +1,10 @@
+//go:build !windows
+
+package cli
+
+import (
+	"github.com/Control-D-Inc/ctrld"
+)
+
+// addExtraSplitDnsRule adds split DNS rule if present.
+func addExtraSplitDnsRule(_ *ctrld.ListenerConfig) {}

cmd/cli/ad_windows.go

@@ -0,0 +1,43 @@
+package cli
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/Control-D-Inc/ctrld"
+)
+
+// addExtraSplitDnsRule adds split DNS rule for domain if it's part of active directory.
+func addExtraSplitDnsRule(lc *ctrld.ListenerConfig) {
+	if lc.Policy == nil {
+		lc.Policy = &ctrld.ListenerPolicyConfig{}
+	}
+	domain, err := getActiveDirectoryDomain()
+	if err != nil {
+		mainLog.Load().Debug().Msgf("unable to get active directory domain: %v", err)
+		return
+	}
+	if domain == "" {
+		mainLog.Load().Debug().Msg("no active directory domain found")
+		return
+	}
+	domainRule := "*." + strings.TrimPrefix(domain, ".")
+	for _, rule := range lc.Policy.Rules {
+		if _, ok := rule[domainRule]; ok {
+			mainLog.Load().Debug().Msg("domain rule already exist")
+			return
+		}
+	}
+	mainLog.Load().Debug().Msg("adding active directory domain")
+	lc.Policy.Rules = append(lc.Policy.Rules, ctrld.Rule{domainRule: []string{}})
+}
+
+// getActiveDirectoryDomain returns AD domain name of this computer.
+func getActiveDirectoryDomain() (string, error) {
+	cmd := "$obj = GetWmiObject Win32_ComputerSystem; if ($obj.PartOfDomain) { $obj.Domain }"
+	output, err := powershell(cmd)
+	if err != nil {
+		return "", fmt.Errorf("failed to get domain name: %w, output:\n\n%s", err, string(output))
+	}
+	return string(output), nil
+}

cmd/cli/prog.go

@@ -435,6 +435,7 @@ func (p *prog) run(reload bool, reloadCh chan struct{}) {
 
 	for listenerNum := range p.cfg.Listener {
 		p.cfg.Listener[listenerNum].Init()
+		addExtraSplitDnsRule(p.cfg.Listener[listenerNum])
 		if !reload {
 			go func(listenerNum string) {
 				listenerConfig := p.cfg.Listener[listenerNum]