package dns import ( "context" "crypto/tls" "fmt" "net" "net/netip" "time" "github.com/Dreamacro/clash/common/cache" "github.com/Dreamacro/clash/component/dialer" C "github.com/Dreamacro/clash/constant" "github.com/Dreamacro/clash/log" "github.com/Dreamacro/clash/tunnel" D "github.com/miekg/dns" ) func putMsgToCache(c *cache.LruCache[string, *D.Msg], key string, msg *D.Msg) { var ttl uint32 switch { case len(msg.Answer) != 0: ttl = msg.Answer[0].Header().Ttl case len(msg.Ns) != 0: ttl = msg.Ns[0].Header().Ttl case len(msg.Extra) != 0: ttl = msg.Extra[0].Header().Ttl default: log.Debugln("[DNS] response msg empty: %#v", msg) return } c.SetWithExpire(key, msg.Copy(), time.Now().Add(time.Second*time.Duration(ttl))) } func setMsgTTL(msg *D.Msg, ttl uint32) { for _, answer := range msg.Answer { answer.Header().Ttl = ttl } for _, ns := range msg.Ns { ns.Header().Ttl = ttl } for _, extra := range msg.Extra { extra.Header().Ttl = ttl } } func isIPRequest(q D.Question) bool { return q.Qclass == D.ClassINET && (q.Qtype == D.TypeA || q.Qtype == D.TypeAAAA) } func transform(servers []NameServer, resolver *Resolver) []dnsClient { ret := []dnsClient{} for _, s := range servers { switch s.Net { case "https": ret = append(ret, newDoHClient(s.Addr, resolver, s.ProxyAdapter)) continue case "dhcp": ret = append(ret, newDHCPClient(s.Addr)) continue case "quic": ret = append(ret, &quicClient{addr: s.Addr}) continue } host, port, _ := net.SplitHostPort(s.Addr) ret = append(ret, &client{ Client: &D.Client{ Net: s.Net, TLSConfig: &tls.Config{ // alpn identifier, see https://tools.ietf.org/html/draft-hoffman-dprive-dns-tls-alpn-00#page-6 NextProtos: []string{"dns"}, ServerName: host, }, UDPSize: 4096, Timeout: 5 * time.Second, }, port: port, host: host, iface: s.Interface, r: resolver, proxyAdapter: s.ProxyAdapter, }) } return ret } func handleMsgWithEmptyAnswer(r *D.Msg) *D.Msg { msg := &D.Msg{} msg.Answer = []D.RR{} msg.SetRcode(r, D.RcodeSuccess) msg.Authoritative = true msg.RecursionAvailable = true return msg } func msgToIP(msg *D.Msg) []net.IP { ips := []net.IP{} for _, answer := range msg.Answer { switch ans := answer.(type) { case *D.AAAA: ips = append(ips, ans.AAAA) case *D.A: ips = append(ips, ans.A) } } return ips } func ipToAddr(ip net.IP) netip.Addr { if ip == nil { return netip.Addr{} } l := len(ip) if l == 4 { return netip.AddrFrom4(*(*[4]byte)(ip)) } else if l == 16 { return netip.AddrFrom16(*(*[16]byte)(ip)) } else { return netip.Addr{} } } type wrapPacketConn struct { net.PacketConn rAddr net.Addr } func (wpc *wrapPacketConn) Read(b []byte) (n int, err error) { n, _, err = wpc.PacketConn.ReadFrom(b) return n, err } func (wpc *wrapPacketConn) Write(b []byte) (n int, err error) { return wpc.PacketConn.WriteTo(b, wpc.rAddr) } func (wpc *wrapPacketConn) RemoteAddr() net.Addr { return wpc.rAddr } func dialContextWithProxyAdapter(ctx context.Context, adapterName string, network string, dstIP net.IP, port string, opts ...dialer.Option) (net.Conn, error) { adapter, ok := tunnel.Proxies()[adapterName] if !ok { return nil, fmt.Errorf("proxy adapter [%s] not found", adapterName) } networkType := C.TCP if network == "udp" { if !adapter.SupportUDP() { return nil, fmt.Errorf("proxy adapter [%s] UDP is not supported", adapterName) } networkType = C.UDP } addrType := C.AtypIPv4 if dstIP.To4() == nil { addrType = C.AtypIPv6 } metadata := &C.Metadata{ NetWork: networkType, AddrType: addrType, Host: "", DstIP: dstIP, DstPort: port, } if networkType == C.UDP { packetConn, err := adapter.ListenPacketContext(ctx, metadata, opts...) if err != nil { return nil, err } return &wrapPacketConn{ PacketConn: packetConn, rAddr: metadata.UDPAddr(), }, nil } return adapter.DialContext(ctx, metadata, opts...) }