fix: dns specified interface does not change

config/config.go

@@ -689,7 +689,7 @@ func parseNameServer(servers []string) ([]dns.NameServer, error) {
 				Net:          dnsNetType,
 				Addr:         addr,
 				ProxyAdapter: u.Fragment,
-				Interface:    dialer.DefaultInterface.Load(),
+				Interface:    dialer.DefaultInterface,
 			},
 		)
 	}

dns/client.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
+	"go.uber.org/atomic"
 	"net"
 	"net/netip"
 	"strings"
@@ -19,7 +20,7 @@ type client struct {
 	r            *Resolver
 	port         string
 	host         string
-	iface        string
+	iface        *atomic.String
 	proxyAdapter string
 }
 
@@ -49,8 +50,8 @@ func (c *client) ExchangeContext(ctx context.Context, m *D.Msg) (*D.Msg, error)
 	}
 
 	options := []dialer.Option{}
-	if c.iface != "" {
-		options = append(options, dialer.WithInterface(c.iface))
+	if c.iface != nil && c.iface.Load() != "" {
+		options = append(options, dialer.WithInterface(c.iface.Load()))
 	}
 
 	var conn net.Conn

dns/resolver.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"go.uber.org/atomic"
 	"math/rand"
 	"net/netip"
 	"strings"
@@ -356,7 +357,7 @@ func (r *Resolver) HasProxyServer() bool {
 type NameServer struct {
 	Net          string
 	Addr         string
-	Interface    string
+	Interface    *atomic.String
 	ProxyAdapter string
 }