[WIP] feat: add DoQ Method in dns resolver

app/cmd/server.go

@@ -141,12 +141,19 @@ type serverConfigResolverHTTPS struct {
 	Insecure bool          `mapstructure:"insecure"`
 }
 
+type serverConfigResolverQUIC struct {
+	Addr     string `mapstructure:"addr"`
+	Sni      string `mapstructure:"sni"`
+	Insecure bool   `mapstructure:"insecure"`
+}
+
 type serverConfigResolver struct {
 	Type  string                    `mapstructure:"type"`
 	TCP   serverConfigResolverTCP   `mapstructure:"tcp"`
 	UDP   serverConfigResolverUDP   `mapstructure:"udp"`
 	TLS   serverConfigResolverTLS   `mapstructure:"tls"`
 	HTTPS serverConfigResolverHTTPS `mapstructure:"https"`
+	QUIC  serverConfigResolverQUIC  `mapstructure:"quic"`
 }
 
 type serverConfigACL struct {
@@ -527,6 +534,15 @@ func (c *serverConfig) fillOutboundConfig(hyConfig *server.Config) error {
 			return configError{Field: "resolver.https.addr", Err: errors.New("empty resolver address")}
 		}
 		uOb = outbounds.NewDoHResolver(c.Resolver.HTTPS.Addr, c.Resolver.HTTPS.Timeout, c.Resolver.HTTPS.SNI, c.Resolver.HTTPS.Insecure, uOb)
+	case "quic":
+		if c.Resolver.QUIC.Addr == "" {
+			return configError{Field: "resolver.quic.addr", Err: errors.New("empty resolver address")}
+		}
+		var err error
+		uOb, err = outbounds.NewDOQResolver(c.Resolver.QUIC.Addr, c.Resolver.QUIC.Sni, c.Resolver.QUIC.Insecure, uOb)
+		if err != nil {
+			return configError{Field: "resolver.quic", Err: err}
+		}
 	default:
 		return configError{Field: "resolver.type", Err: errors.New("unsupported resolver type")}
 	}

extras/outbounds/dns_quic.go

@@ -0,0 +1,191 @@
+package outbounds
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/apernet/quic-go"
+	"github.com/miekg/dns"
+)
+
+// DoqResolver Client stores a DoQ client
+type DoqResolver struct {
+	Resolver doqClient
+	Next     PluggableOutbound
+}
+
+type doqClient struct {
+	ctx  context.Context
+	conn quic.Connection
+}
+
+func NewDOQResolver(server, sni string, tlsInsecureSkipVerify bool, next PluggableOutbound) (PluggableOutbound, error) {
+	d, err := newDoqClient(server, sni, tlsInsecureSkipVerify)
+	if err != nil {
+		return nil, err
+	}
+
+	return &DoqResolver{
+		Resolver: *d,
+		Next:     next,
+	}, nil
+}
+
+func newDoqClient(server, sni string, tlsInsecureSkipVerify bool) (*doqClient, error) {
+	var d doqClient
+	var err error
+	d.ctx = context.Background()
+	serverAddr := strings.SplitN(server, ":", 2)
+	if len(serverAddr) != 2 {
+		// DOQ: If the port is not specified, use the default port 853
+		server = server + ":853"
+	}
+	if sni == "" {
+		// DOQ: If the SNI is not specified, use the server address host
+		sni = serverAddr[0]
+	}
+	d.conn, err = quic.DialAddrEarly(d.ctx, server, &tls.Config{
+		ServerName:             sni,
+		InsecureSkipVerify:     tlsInsecureSkipVerify,
+		NextProtos:             []string{"doq"},
+		SessionTicketsDisabled: false,
+	}, &quic.Config{
+		KeepAlivePeriod: 20 * time.Second,
+		TokenStore:      quic.NewLRUTokenStore(1, 10),
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &d, nil
+}
+
+func (r *DoqResolver) resolve(reqAddr *AddrEx) {
+	if tryParseIP(reqAddr) {
+		// The host is already an IP address, we don't need to resolve it.
+		return
+	}
+	type lookupResult struct {
+		ip  net.IP
+		err error
+	}
+	ch4, ch6 := make(chan lookupResult, 1), make(chan lookupResult, 1)
+	go func() {
+		recs, err := r.Resolver.LookupA(reqAddr.Host)
+		var ip net.IP
+		if err == nil && len(recs) > 0 {
+			ip = recs[0].A
+		}
+		ch4 <- lookupResult{ip, err}
+	}()
+	go func() {
+		recs, err := r.Resolver.LookupAAAA(reqAddr.Host)
+		var ip net.IP
+		if err == nil && len(recs) > 0 {
+			ip = recs[0].AAAA
+		}
+		ch6 <- lookupResult{ip, err}
+	}()
+	result4, result6 := <-ch4, <-ch6
+	reqAddr.ResolveInfo = &ResolveInfo{
+		IPv4: result4.ip,
+		IPv6: result6.ip,
+	}
+	if result4.err != nil {
+		reqAddr.ResolveInfo.Err = result4.err
+	} else if result6.err != nil {
+		reqAddr.ResolveInfo.Err = result6.err
+	}
+}
+
+func (r *DoqResolver) TCP(reqAddr *AddrEx) (net.Conn, error) {
+	r.resolve(reqAddr)
+	return r.Next.TCP(reqAddr)
+}
+
+func (r *DoqResolver) UDP(reqAddr *AddrEx) (UDPConn, error) {
+	r.resolve(reqAddr)
+	return r.Next.UDP(reqAddr)
+}
+
+// Close closes a Client QUIC connection
+func (c *doqClient) Close() error {
+	return c.conn.CloseWithError(0, "")
+}
+
+func (c *doqClient) LookupA(name string) ([]dns.A, error) {
+	var msg dns.Msg
+	msg.SetQuestion(fmt.Sprintf("%s.", name), dns.TypeA)
+	resp, err := c.Lookup(msg)
+	if err != nil {
+		return nil, err
+	}
+	var ret []dns.A
+	for _, a := range resp.Answer {
+		if ans, ok := a.(*dns.A); ok {
+			ret = append(ret, *ans)
+		}
+	}
+	return ret, nil
+}
+
+func (c *doqClient) LookupAAAA(name string) ([]dns.AAAA, error) {
+	var msg dns.Msg
+	msg.SetQuestion(fmt.Sprintf("%s.", name), dns.TypeAAAA)
+	resp, err := c.Lookup(msg)
+	if err != nil {
+		return nil, err
+	}
+	var ret []dns.AAAA
+	for _, a := range resp.Answer {
+		if ans, ok := a.(*dns.AAAA); ok {
+			ret = append(ret, *ans)
+		}
+	}
+	return ret, nil
+}
+
+// Lookup sends a DNS query to the server and returns the response
+// Code From: https://github.com/natesales/doqd/blob/main/pkg/client/main.go
+func (c *doqClient) Lookup(message dns.Msg) (dns.Msg, error) {
+	// Open a new QUIC stream
+	stream, err := c.conn.OpenStreamSync(c.ctx)
+	if err != nil {
+		return dns.Msg{}, errors.New("quic stream open: " + err.Error())
+	}
+
+	// Pack the DNS message for transmission
+	packed, err := message.Pack()
+	if err != nil {
+		_ = stream.Close()
+		return dns.Msg{}, errors.New("dns message pack: " + err.Error())
+	}
+
+	_, err = stream.Write(packed)
+	if err != nil {
+		_ = stream.Close()
+		return dns.Msg{}, errors.New("quic stream write: " + err.Error())
+	}
+	// Close the stream after writing the message
+	_ = stream.Close()
+
+	// Read the response from the QUIC stream
+	buffer, err := io.ReadAll(stream)
+	if err != nil {
+		return dns.Msg{}, errors.New("quic stream read: " + err.Error())
+	}
+
+	// Unpack the DNS message
+	var msg dns.Msg
+	err = msg.Unpack(buffer)
+	if err != nil {
+		return dns.Msg{}, errors.New("dns message unpack: " + err.Error())
+	}
+
+	return msg, nil // nil error
+}