package dns import ( stdContext "context" "errors" "net" "github.com/metacubex/mihomo/adapter/inbound" "github.com/metacubex/mihomo/common/sockopt" "github.com/metacubex/mihomo/context" "github.com/metacubex/mihomo/log" D "github.com/miekg/dns" ) var ( address string server = &Server{} dnsDefaultTTL uint32 = 600 ) type Server struct { handler handler tcpServer *D.Server udpServer *D.Server } // ServeDNS implement D.Handler ServeDNS func (s *Server) ServeDNS(w D.ResponseWriter, r *D.Msg) { msg, err := handlerWithContext(stdContext.Background(), s.handler, r) if err != nil { D.HandleFailed(w, r) return } msg.Compress = true w.WriteMsg(msg) } func handlerWithContext(stdCtx stdContext.Context, handler handler, msg *D.Msg) (*D.Msg, error) { if len(msg.Question) == 0 { return nil, errors.New("at least one question is required") } ctx := context.NewDNSContext(stdCtx, msg) return handler(ctx, msg) } func (s *Server) SetHandler(handler handler) { s.handler = handler } func ReCreateServer(addr string, resolver *Resolver, mapper *ResolverEnhancer) { if addr == address && resolver != nil { handler := NewHandler(resolver, mapper) server.SetHandler(handler) return } if server.tcpServer != nil { _ = server.tcpServer.Shutdown() server.tcpServer = nil } if server.udpServer != nil { _ = server.udpServer.Shutdown() server.udpServer = nil } server.handler = nil address = "" if addr == "" { return } var err error defer func() { if err != nil { log.Errorln("Start DNS server error: %s", err.Error()) } }() _, port, err := net.SplitHostPort(addr) if port == "0" || port == "" || err != nil { return } address = addr handler := NewHandler(resolver, mapper) server = &Server{handler: handler} go func() { p, err := inbound.ListenPacket("udp", addr) if err != nil { log.Errorln("Start DNS server(UDP) error: %s", err.Error()) return } if err := sockopt.UDPReuseaddr(p); err != nil { log.Warnln("Failed to Reuse UDP Address: %s", err) } log.Infoln("DNS server(UDP) listening at: %s", p.LocalAddr().String()) server.udpServer = &D.Server{Addr: addr, PacketConn: p, Handler: server} _ = server.udpServer.ActivateAndServe() }() go func() { l, err := inbound.Listen("tcp", addr) if err != nil { log.Errorln("Start DNS server(TCP) error: %s", err.Error()) return } log.Infoln("DNS server(TCP) listening at: %s", l.Addr().String()) server.tcpServer = &D.Server{Addr: addr, Listener: l, Handler: server} _ = server.tcpServer.ActivateAndServe() }() }