Fix: domain dns crash

config/config.go

@@ -441,21 +441,21 @@ func parseHosts(cfg *RawConfig) (*trie.Trie, error) {
 	return tree, nil
 }
 
-func hostWithDefaultPort(host string, defPort string) (string, string, error) {
+func hostWithDefaultPort(host string, defPort string) (string, error) {
 	if !strings.Contains(host, ":") {
 		host += ":"
 	}
 
 	hostname, port, err := net.SplitHostPort(host)
 	if err != nil {
-		return "", "", err
+		return "", err
 	}
 
 	if port == "" {
 		port = defPort
 	}
 
-	return net.JoinHostPort(hostname, port), hostname, nil
+	return net.JoinHostPort(hostname, port), nil
 }
 
 func parseNameServer(servers []string) ([]dns.NameServer, error) {
@@ -471,21 +471,20 @@ func parseNameServer(servers []string) ([]dns.NameServer, error) {
 			return nil, fmt.Errorf("DNS NameServer[%d] format error: %s", idx, err.Error())
 		}
 
-		var addr, dnsNetType, host string
+		var addr, dnsNetType string
 		switch u.Scheme {
 		case "udp":
-			addr, host, err = hostWithDefaultPort(u.Host, "53")
+			addr, err = hostWithDefaultPort(u.Host, "53")
 			dnsNetType = "" // UDP
 		case "tcp":
-			addr, host, err = hostWithDefaultPort(u.Host, "53")
+			addr, err = hostWithDefaultPort(u.Host, "53")
 			dnsNetType = "tcp" // TCP
 		case "tls":
-			addr, host, err = hostWithDefaultPort(u.Host, "853")
+			addr, err = hostWithDefaultPort(u.Host, "853")
 			dnsNetType = "tcp-tls" // DNS over TLS
 		case "https":
 			clearURL := url.URL{Scheme: "https", Host: u.Host, Path: u.Path}
 			addr = clearURL.String()
-			_, host, err = hostWithDefaultPort(u.Host, "853")
 			dnsNetType = "https" // DNS over HTTPS
 		default:
 			return nil, fmt.Errorf("DNS NameServer[%d] unsupport scheme: %s", idx, u.Scheme)
@@ -500,7 +499,6 @@ func parseNameServer(servers []string) ([]dns.NameServer, error) {
 			dns.NameServer{
 				Net:  dnsNetType,
 				Addr: addr,
-				Host: host,
 			},
 		)
 	}
@@ -552,7 +550,8 @@ func parseDNS(cfg RawDNS) (*DNS, error) {
 	}
 	// check default nameserver is pure ip addr
 	for _, ns := range dnsCfg.DefaultNameserver {
-		if net.ParseIP(ns.Host) == nil {
+		host, _, err := net.SplitHostPort(ns.Addr)
+		if err != nil || net.ParseIP(host) == nil {
 			return nil, errors.New("default nameserver should be pure IP")
 		}
 	}

dns/client.go

@@ -2,6 +2,8 @@ package dns
 
 import (
 	"context"
+	"fmt"
+	"net"
 	"strings"
 
 	"github.com/Dreamacro/clash/component/dialer"
@@ -12,7 +14,7 @@ import (
 type client struct {
 	*D.Client
 	r    *Resolver
-	addr string
+	port string
 	host string
 }
 
@@ -21,18 +23,24 @@ func (c *client) Exchange(m *D.Msg) (msg *D.Msg, err error) {
 }
 
 func (c *client) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err error) {
-	network := "udp"
-	if strings.HasPrefix(c.Client.Net, "tcp") {
-		network = "tcp"
-	}
-
-	ip, err := c.r.ResolveIP(c.host)
-	if err != nil {
-		return nil, err
+	var ip net.IP
+	if c.r == nil {
+		// a default ip dns
+		ip = net.ParseIP(c.host)
+	} else {
+		var err error
+		if ip, err = c.r.ResolveIP(c.host); err != nil {
+			println("?")
+			return nil, fmt.Errorf("use default dns resolve failed: %w", err)
+		}
 	}
 
 	d := dialer.Dialer()
 	if dialer.DialHook != nil {
+		network := "udp"
+		if strings.HasPrefix(c.Client.Net, "tcp") {
+			network = "tcp"
+		}
 		dialer.DialHook(d, network, ip)
 	}
 
@@ -46,7 +54,7 @@ func (c *client) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err
 	}
 	ch := make(chan result, 1)
 	go func() {
-		msg, _, err := c.Client.Exchange(m, c.addr)
+		msg, _, err := c.Client.Exchange(m, net.JoinHostPort(ip.String(), c.port))
 		ch <- result{msg, err}
 	}()
 

dns/resolver.go

@@ -263,7 +263,6 @@ func (r *Resolver) asyncExchange(client []dnsClient, msg *D.Msg) <-chan *result
 type NameServer struct {
 	Net  string
 	Addr string
-	Host string
 }
 
 type FallbackFilter struct {

dns/util.go

@@ -4,6 +4,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"errors"
+	"net"
 	"time"
 
 	"github.com/Dreamacro/clash/common/cache"
@@ -125,6 +126,7 @@ func transform(servers []NameServer, resolver *Resolver) []dnsClient {
 			continue
 		}
 
+		host, port, _ := net.SplitHostPort(s.Addr)
 		ret = append(ret, &client{
 			Client: &D.Client{
 				Net: s.Net,
@@ -136,8 +138,9 @@ func transform(servers []NameServer, resolver *Resolver) []dnsClient {
 				UDPSize: 4096,
 				Timeout: 5 * time.Second,
 			},
-			addr: s.Addr,
-			host: s.Host,
+			port: port,
+			host: host,
+			r:    resolver,
 		})
 	}
 	return ret