all: add flush cache domains config

cmd/cli/cli.go

@@ -1831,6 +1831,11 @@ func fieldErrorMsg(fe validator.FieldError) string {
 			return fmt.Sprintf("must define at least %s element", fe.Param())
 		}
 		return fmt.Sprintf("minimum value: %q", fe.Param())
+	case "max":
+		if fe.Kind() == reflect.Map || fe.Kind() == reflect.Slice {
+			return fmt.Sprintf("exceeded maximum number of elements: %s", fe.Param())
+		}
+		return fmt.Sprintf("maximum value: %q", fe.Param())
 	case "len":
 		if fe.Kind() == reflect.Slice {
 			return fmt.Sprintf("must have at least %s element", fe.Param())

cmd/cli/dns_proxy.go

@@ -101,6 +101,10 @@ func (p *prog) serveDNS(listenerNum string) error {
 		go p.detectLoop(m)
 		q := m.Question[0]
 		domain := canonicalName(q.Name)
+		if _, ok := p.cacheFlushDomainsMap[domain]; ok && p.cache != nil {
+			p.cache.Purge()
+			ctrld.Log(ctx, mainLog.Load().Debug(), "received query %q, local cache is purged", domain)
+		}
 		remoteIP, _, _ := net.SplitHostPort(w.RemoteAddr().String())
 		ci := p.getClientInfo(remoteIP, m)
 		ci.ClientIDPref = p.cfg.Service.ClientIDPref

cmd/cli/prog.go

@@ -70,17 +70,18 @@ type prog struct {
 	logConn      net.Conn
 	cs           *controlServer
 
-	cfg            *ctrld.Config
-	localUpstreams []string
-	ptrNameservers []string
-	appCallback    *AppCallback
-	cache          dnscache.Cacher
-	sema           semaphore
-	ciTable        *clientinfo.Table
-	um             *upstreamMonitor
-	router         router.Router
-	ptrLoopGuard   *loopGuard
-	lanLoopGuard   *loopGuard
+	cfg                  *ctrld.Config
+	localUpstreams       []string
+	ptrNameservers       []string
+	appCallback          *AppCallback
+	cache                dnscache.Cacher
+	cacheFlushDomainsMap map[string]struct{}
+	sema                 semaphore
+	ciTable              *clientinfo.Table
+	um                   *upstreamMonitor
+	router               router.Router
+	ptrLoopGuard         *loopGuard
+	lanLoopGuard         *loopGuard
 
 	loopMu sync.Mutex
 	loop   map[string]bool
@@ -253,12 +254,17 @@ func (p *prog) run(reload bool, reloadCh chan struct{}) {
 	p.loop = make(map[string]bool)
 	p.lanLoopGuard = newLoopGuard()
 	p.ptrLoopGuard = newLoopGuard()
+	p.cacheFlushDomainsMap = nil
 	if p.cfg.Service.CacheEnable {
 		cacher, err := dnscache.NewLRUCache(p.cfg.Service.CacheSize)
 		if err != nil {
 			mainLog.Load().Error().Err(err).Msg("failed to create cacher, caching is disabled")
 		} else {
 			p.cache = cacher
+			p.cacheFlushDomainsMap = make(map[string]struct{}, 256)
+			for _, domain := range p.cfg.Service.CacheFlushDomains {
+				p.cacheFlushDomainsMap[canonicalName(domain)] = struct{}{}
+			}
 		}
 	}