all: sync with master

internal/dnsforward/clientid.go

@@ -23,16 +23,6 @@ func ValidateClientID(id string) (err error) {
 	return nil
 }
 
-// hasLabelSuffix returns true if s ends with suffix preceded by a dot.  It's
-// a helper function to prevent unnecessary allocations in code like:
-//
-// if strings.HasSuffix(s, "." + suffix) { /* … */ }
-//
-// s must be longer than suffix.
-func hasLabelSuffix(s, suffix string) (ok bool) {
-	return strings.HasSuffix(s, suffix) && s[len(s)-len(suffix)-1] == '.'
-}
-
 // clientIDFromClientServerName extracts and validates a ClientID.  hostSrvName
 // is the server name of the host.  cliSrvName is the server name as sent by the
 // client.  When strict is true, and client and host server name don't match,
@@ -46,7 +36,7 @@ func clientIDFromClientServerName(
 		return "", nil
 	}
 
-	if !hasLabelSuffix(cliSrvName, hostSrvName) {
+	if !netutil.IsImmediateSubdomain(cliSrvName, hostSrvName) {
 		if !strict {
 			return "", nil
 		}

internal/dnsforward/dnsforward.go

@@ -246,6 +246,7 @@ type RDNSExchanger interface {
 	// Exchange tries to resolve the ip in a suitable way, e.g. either as
 	// local or as external.
 	Exchange(ip net.IP) (host string, err error)
+
 	// ResolvesPrivatePTR returns true if the RDNSExchanger is able to
 	// resolve PTR requests for locally-served addresses.
 	ResolvesPrivatePTR() (ok bool)
@@ -261,6 +262,9 @@ const (
 	rDNSNotPTRErr errors.Error = "the response is not a ptr"
 )
 
+// type check
+var _ RDNSExchanger = (*Server)(nil)
+
 // Exchange implements the RDNSExchanger interface for *Server.
 func (s *Server) Exchange(ip net.IP) (host string, err error) {
 	s.serverLock.RLock()
@@ -675,21 +679,13 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 // IsBlockedClient returns true if the client is blocked by the current access
 // settings.
-func (s *Server) IsBlockedClient(ip net.IP, clientID string) (blocked bool, rule string) {
+func (s *Server) IsBlockedClient(ip netip.Addr, clientID string) (blocked bool, rule string) {
 	s.serverLock.RLock()
 	defer s.serverLock.RUnlock()
 
 	blockedByIP := false
-	if ip != nil {
-		// TODO(a.garipov):  Remove once we switch to netip.Addr more fully.
-		ipAddr, err := netutil.IPToAddrNoMapped(ip)
-		if err != nil {
-			log.Error("dnsforward: bad client ip %v: %s", ip, err)
-
-			return false, ""
-		}
-
-		blockedByIP, rule = s.access.isBlockedIP(ipAddr)
+	if ip != (netip.Addr{}) {
+		blockedByIP, rule = s.access.isBlockedIP(ip)
 	}
 
 	allowlistMode := s.access.allowlistMode()

internal/dnsforward/filter.go

@@ -19,13 +19,13 @@ func (s *Server) beforeRequestHandler(
 	_ *proxy.Proxy,
 	pctx *proxy.DNSContext,
 ) (reply bool, err error) {
-	ip, _ := netutil.IPAndPortFromAddr(pctx.Addr)
 	clientID, err := s.clientIDFromDNSContext(pctx)
 	if err != nil {
 		return false, fmt.Errorf("getting clientid: %w", err)
 	}
 
-	blocked, _ := s.IsBlockedClient(ip, clientID)
+	addrPort := netutil.NetAddrToAddrPort(pctx.Addr)
+	blocked, _ := s.IsBlockedClient(addrPort.Addr(), clientID)
 	if blocked {
 		return s.preBlockedResponse(pctx)
 	}