chore: rebuild udp dns resolve

The DNS resolution of the overall UDP part has been delayed to the connection initiation stage. During the rule matching process, it will only be triggered when the IP rule without no-resolve is matched.

For direct and wireguard outbound, the same logic as the TCP part will be followed, that is, when direct-nameserver (or DNS configured by wireguard) exists, the result of the matching process will be discarded and the domain name will be re-resolved. This re-resolution logic is only effective for fakeip.

For reject and DNS outbound, no resolution is required.

For other outbound, resolution will still be performed when the connection is initiated, and the domain name will not be sent directly to the remote server at present.

adapter/outbound/anytls.go

@@ -2,7 +2,6 @@ package outbound
 
 import (
 	"context"
-	"errors"
 	"net"
 	"strconv"
 	"time"
@@ -10,7 +9,6 @@ import (
 	CN "github.com/metacubex/mihomo/common/net"
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/proxydialer"
-	"github.com/metacubex/mihomo/component/resolver"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/transport/anytls"
 	"github.com/metacubex/mihomo/transport/vmess"
@@ -53,6 +51,10 @@ func (t *AnyTLS) DialContext(ctx context.Context, metadata *C.Metadata) (_ C.Con
 }
 
 func (t *AnyTLS) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_ C.PacketConn, err error) {
+	if err = t.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
+
 	// create tcp
 	c, err := t.client.CreateProxy(ctx, uot.RequestDestination(2))
 	if err != nil {
@@ -60,13 +62,6 @@ func (t *AnyTLS) ListenPacketContext(ctx context.Context, metadata *C.Metadata)
 	}
 
 	// create uot on tcp
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
-	}
 	destination := M.SocksaddrFromNet(metadata.UDPAddr())
 	return newPacketConn(CN.NewThreadSafePacketConn(uot.NewLazyConn(c, uot.Request{Destination: destination})), t), nil
 }

adapter/outbound/base.go

@@ -3,6 +3,7 @@ package outbound
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"net"
 	"runtime"
 	"sync"
@@ -11,6 +12,7 @@ import (
 	N "github.com/metacubex/mihomo/common/net"
 	"github.com/metacubex/mihomo/common/utils"
 	"github.com/metacubex/mihomo/component/dialer"
+	"github.com/metacubex/mihomo/component/resolver"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/log"
 )
@@ -18,6 +20,7 @@ import (
 type ProxyAdapter interface {
 	C.ProxyAdapter
 	DialOptions() []dialer.Option
+	ResolveUDP(ctx context.Context, metadata *C.Metadata) error
 }
 
 type Base struct {
@@ -159,6 +162,17 @@ func (b *Base) DialOptions() (opts []dialer.Option) {
 	return opts
 }
 
+func (b *Base) ResolveUDP(ctx context.Context, metadata *C.Metadata) error {
+	if !metadata.Resolved() {
+		ip, err := resolver.ResolveIP(ctx, metadata.Host)
+		if err != nil {
+			return fmt.Errorf("can't resolve ip: %w", err)
+		}
+		metadata.DstIP = ip
+	}
+	return nil
+}
+
 func (b *Base) Close() error {
 	return nil
 }
@@ -258,6 +272,11 @@ type packetConn struct {
 	adapterName string
 	connID      string
 	adapterAddr string
+	resolveUDP  func(ctx context.Context, metadata *C.Metadata) error
+}
+
+func (c *packetConn) ResolveUDP(ctx context.Context, metadata *C.Metadata) error {
+	return c.resolveUDP(ctx, metadata)
 }
 
 func (c *packetConn) RemoteDestination() string {
@@ -296,12 +315,12 @@ func (c *packetConn) AddRef(ref any) {
 	c.EnhancePacketConn = N.NewRefPacketConn(c.EnhancePacketConn, ref) // add ref for autoCloseProxyAdapter
 }
 
-func newPacketConn(pc net.PacketConn, a C.ProxyAdapter) C.PacketConn {
+func newPacketConn(pc net.PacketConn, a ProxyAdapter) C.PacketConn {
 	epc := N.NewEnhancePacketConn(pc)
 	if _, ok := pc.(syscall.Conn); !ok { // exclusion system conn like *net.UDPConn
 		epc = N.NewDeadlineEnhancePacketConn(epc) // most conn from outbound can't handle readDeadline correctly
 	}
-	return &packetConn{epc, []string{a.Name()}, a.Name(), utils.NewUUIDV4().String(), a.Addr()}
+	return &packetConn{epc, []string{a.Name()}, a.Name(), utils.NewUUIDV4().String(), a.Addr(), a.ResolveUDP}
 }
 
 type AddRef interface {

adapter/outbound/direct.go

@@ -2,7 +2,8 @@ package outbound
 
 import (
 	"context"
-	"errors"
+	"fmt"
+
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/loopback"
 	"github.com/metacubex/mihomo/component/resolver"
@@ -38,13 +39,8 @@ func (d *Direct) ListenPacketContext(ctx context.Context, metadata *C.Metadata)
 	if err := d.loopBack.CheckPacketConn(metadata); err != nil {
 		return nil, err
 	}
-	// net.UDPConn.WriteTo only working with *net.UDPAddr, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIPWithResolver(ctx, metadata.Host, resolver.DirectHostResolver)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err := d.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 	pc, err := dialer.NewDialer(d.DialOptions()...).ListenPacket(ctx, "udp", "", metadata.AddrPort())
 	if err != nil {
@@ -53,6 +49,17 @@ func (d *Direct) ListenPacketContext(ctx context.Context, metadata *C.Metadata)
 	return d.loopBack.NewPacketConn(newPacketConn(pc, d)), nil
 }
 
+func (d *Direct) ResolveUDP(ctx context.Context, metadata *C.Metadata) error {
+	if (!metadata.Resolved() || resolver.DirectHostResolver != resolver.DefaultResolver) && metadata.Host != "" {
+		ip, err := resolver.ResolveIPWithResolver(ctx, metadata.Host, resolver.DirectHostResolver)
+		if err != nil {
+			return fmt.Errorf("can't resolve ip: %w", err)
+		}
+		metadata.DstIP = ip
+	}
+	return nil
+}
+
 func (d *Direct) IsL3Protocol(metadata *C.Metadata) bool {
 	return true // tell DNSDialer don't send domain to DialContext, avoid lookback to DefaultResolver
 }

adapter/outbound/dns.go

@@ -3,6 +3,7 @@ package outbound
 import (
 	"context"
 	"net"
+	"net/netip"
 	"time"
 
 	N "github.com/metacubex/mihomo/common/net"
@@ -31,6 +32,9 @@ func (d *Dns) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, er
 // ListenPacketContext implements C.ProxyAdapter
 func (d *Dns) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (C.PacketConn, error) {
 	log.Debugln("[DNS] hijack udp:%s from %s", metadata.RemoteAddress(), metadata.SourceAddrPort())
+	if err := d.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 
 	ctx, cancel := context.WithCancel(context.Background())
 
@@ -41,6 +45,13 @@ func (d *Dns) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (C.
 	}, d), nil
 }
 
+func (d *Dns) ResolveUDP(ctx context.Context, metadata *C.Metadata) error {
+	if !metadata.Resolved() {
+		metadata.DstIP = netip.AddrFrom4([4]byte{127, 0, 0, 2})
+	}
+	return nil
+}
+
 type dnsPacket struct {
 	data []byte
 	put  func()

adapter/outbound/hysteria.go

@@ -60,6 +60,9 @@ func (h *Hysteria) DialContext(ctx context.Context, metadata *C.Metadata) (C.Con
 }
 
 func (h *Hysteria) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (C.PacketConn, error) {
+	if err := h.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	udpConn, err := h.client.DialUDP(h.genHdc(ctx))
 	if err != nil {
 		return nil, err

adapter/outbound/hysteria2.go

@@ -77,6 +77,9 @@ func (h *Hysteria2) DialContext(ctx context.Context, metadata *C.Metadata) (_ C.
 }
 
 func (h *Hysteria2) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_ C.PacketConn, err error) {
+	if err = h.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	pc, err := h.client.ListenPacket(ctx)
 	if err != nil {
 		return nil, err

adapter/outbound/mieru.go

@@ -54,6 +54,9 @@ func (m *Mieru) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn,
 
 // ListenPacketContext implements C.ProxyAdapter
 func (m *Mieru) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_ C.PacketConn, err error) {
+	if err = m.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	if err := m.ensureClientIsRunning(); err != nil {
 		return nil, err
 	}

adapter/outbound/reject.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 	"net"
+	"net/netip"
 	"time"
 
 	"github.com/metacubex/mihomo/common/buf"
@@ -29,9 +30,19 @@ func (r *Reject) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn,
 
 // ListenPacketContext implements C.ProxyAdapter
 func (r *Reject) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (C.PacketConn, error) {
+	if err := r.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	return newPacketConn(&nopPacketConn{}, r), nil
 }
 
+func (r *Reject) ResolveUDP(ctx context.Context, metadata *C.Metadata) error {
+	if !metadata.Resolved() {
+		metadata.DstIP = netip.IPv4Unspecified()
+	}
+	return nil
+}
+
 func NewRejectWithOption(option RejectOption) *Reject {
 	return &Reject{
 		Base: &Base{

adapter/outbound/shadowsocks.go

@@ -2,7 +2,6 @@ package outbound
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"net"
 	"strconv"
@@ -11,7 +10,6 @@ import (
 	"github.com/metacubex/mihomo/common/structure"
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/proxydialer"
-	"github.com/metacubex/mihomo/component/resolver"
 	C "github.com/metacubex/mihomo/constant"
 	gost "github.com/metacubex/mihomo/transport/gost-plugin"
 	"github.com/metacubex/mihomo/transport/restls"
@@ -202,6 +200,9 @@ func (ss *ShadowSocks) ListenPacketWithDialer(ctx context.Context, dialer C.Dial
 			return nil, err
 		}
 	}
+	if err = ss.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	addr, err := resolveUDPAddr(ctx, "udp", ss.addr, ss.prefer)
 	if err != nil {
 		return nil, err
@@ -230,15 +231,9 @@ func (ss *ShadowSocks) ProxyInfo() C.ProxyInfo {
 // ListenPacketOnStreamConn implements C.ProxyAdapter
 func (ss *ShadowSocks) ListenPacketOnStreamConn(ctx context.Context, c net.Conn, metadata *C.Metadata) (_ C.PacketConn, err error) {
 	if ss.option.UDPOverTCP {
-		// ss uot use stream-oriented udp with a special address, so we need a net.UDPAddr
-		if !metadata.Resolved() {
-			ip, err := resolver.ResolveIP(ctx, metadata.Host)
-			if err != nil {
-				return nil, errors.New("can't resolve ip")
-			}
-			metadata.DstIP = ip
+		if err = ss.ResolveUDP(ctx, metadata); err != nil {
+			return nil, err
 		}
-
 		destination := M.SocksaddrFromNet(metadata.UDPAddr())
 		if ss.option.UDPOverTCPVersion == uot.LegacyVersion {
 			return newPacketConn(N.NewThreadSafePacketConn(uot.NewConn(c, uot.Request{Destination: destination})), ss), nil

adapter/outbound/shadowsocksr.go

@@ -105,6 +105,9 @@ func (ssr *ShadowSocksR) ListenPacketWithDialer(ctx context.Context, dialer C.Di
 			return nil, err
 		}
 	}
+	if err = ssr.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	addr, err := resolveUDPAddr(ctx, "udp", ssr.addr, ssr.prefer)
 	if err != nil {
 		return nil, err

adapter/outbound/singmux.go

@@ -2,12 +2,10 @@ package outbound
 
 import (
 	"context"
-	"errors"
 
 	CN "github.com/metacubex/mihomo/common/net"
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/proxydialer"
-	"github.com/metacubex/mihomo/component/resolver"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/log"
 
@@ -53,16 +51,9 @@ func (s *SingMux) ListenPacketContext(ctx context.Context, metadata *C.Metadata)
 	if s.onlyTcp {
 		return s.ProxyAdapter.ListenPacketContext(ctx, metadata)
 	}
-
-	// sing-mux use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = s.ProxyAdapter.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
-
 	pc, err := s.client.ListenPacket(ctx, M.SocksaddrFromNet(metadata.UDPAddr()))
 	if err != nil {
 		return nil, err

adapter/outbound/snell.go

@@ -127,6 +127,9 @@ func (s *Snell) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, met
 			return nil, err
 		}
 	}
+	if err = s.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	c, err := dialer.DialContext(ctx, "tcp", s.addr)
 	if err != nil {
 		return nil, err

adapter/outbound/socks5.go

@@ -109,6 +109,9 @@ func (ss *Socks5) ListenPacketContext(ctx context.Context, metadata *C.Metadata)
 			return nil, err
 		}
 	}
+	if err = ss.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	c, err := cDialer.DialContext(ctx, "tcp", ss.addr)
 	if err != nil {
 		err = fmt.Errorf("%s connect error: %w", ss.addr, err)

adapter/outbound/trojan.go

@@ -219,6 +219,10 @@ func (t *Trojan) DialContextWithDialer(ctx context.Context, dialer C.Dialer, met
 
 // ListenPacketContext implements C.ProxyAdapter
 func (t *Trojan) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_ C.PacketConn, err error) {
+	if err = t.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
+
 	var c net.Conn
 
 	// grpc transport
@@ -250,6 +254,9 @@ func (t *Trojan) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, me
 			return nil, err
 		}
 	}
+	if err = t.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
 	c, err := dialer.DialContext(ctx, "tcp", t.addr)
 	if err != nil {
 		return nil, fmt.Errorf("%s connect error: %w", t.addr, err)
@@ -271,12 +278,6 @@ func (t *Trojan) SupportWithDialer() C.NetWork {
 	return C.ALLNet
 }
 
-// ListenPacketOnStreamConn implements C.ProxyAdapter
-func (t *Trojan) ListenPacketOnStreamConn(c net.Conn, metadata *C.Metadata) (_ C.PacketConn, err error) {
-	pc := trojan.NewPacketConn(c)
-	return newPacketConn(pc, t), err
-}
-
 // SupportUOT implements C.ProxyAdapter
 func (t *Trojan) SupportUOT() bool {
 	return true

adapter/outbound/tuic.go

@@ -3,7 +3,6 @@ package outbound
 import (
 	"context"
 	"crypto/tls"
-	"errors"
 	"fmt"
 	"math"
 	"net"
@@ -14,7 +13,6 @@ import (
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/ech"
 	"github.com/metacubex/mihomo/component/proxydialer"
-	"github.com/metacubex/mihomo/component/resolver"
 	tlsC "github.com/metacubex/mihomo/component/tls"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/transport/tuic"
@@ -91,6 +89,10 @@ func (t *Tuic) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_
 
 // ListenPacketWithDialer implements C.ProxyAdapter
 func (t *Tuic) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, metadata *C.Metadata) (_ C.PacketConn, err error) {
+	if err = t.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
+	}
+
 	if t.option.UDPOverStream {
 		uotDestination := uot.RequestDestination(uint8(t.option.UDPOverStreamVersion))
 		uotMetadata := *metadata
@@ -102,13 +104,6 @@ func (t *Tuic) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, meta
 		}
 
 		// tuic uos use stream-oriented udp with a special address, so we need a net.UDPAddr
-		if !metadata.Resolved() {
-			ip, err := resolver.ResolveIP(ctx, metadata.Host)
-			if err != nil {
-				return nil, errors.New("can't resolve ip")
-			}
-			metadata.DstIP = ip
-		}
 
 		destination := M.SocksaddrFromNet(metadata.UDPAddr())
 		if t.option.UDPOverStreamVersion == uot.LegacyVersion {

adapter/outbound/vless.go

@@ -19,7 +19,6 @@ import (
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/ech"
 	"github.com/metacubex/mihomo/component/proxydialer"
-	"github.com/metacubex/mihomo/component/resolver"
 	tlsC "github.com/metacubex/mihomo/component/tls"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/transport/gun"
@@ -277,13 +276,8 @@ func (v *Vless) DialContextWithDialer(ctx context.Context, dialer C.Dialer, meta
 
 // ListenPacketContext implements C.ProxyAdapter
 func (v *Vless) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_ C.PacketConn, err error) {
-	// vless use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = v.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 	var c net.Conn
 	// gun transport
@@ -315,13 +309,8 @@ func (v *Vless) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, met
 		}
 	}
 
-	// vless use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = v.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 
 	c, err := dialer.DialContext(ctx, "tcp", v.addr)
@@ -347,13 +336,8 @@ func (v *Vless) SupportWithDialer() C.NetWork {
 
 // ListenPacketOnStreamConn implements C.ProxyAdapter
 func (v *Vless) ListenPacketOnStreamConn(ctx context.Context, c net.Conn, metadata *C.Metadata) (_ C.PacketConn, err error) {
-	// vless use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = v.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 
 	if v.option.XUDP {

adapter/outbound/vmess.go

@@ -17,7 +17,6 @@ import (
 	"github.com/metacubex/mihomo/component/dialer"
 	"github.com/metacubex/mihomo/component/ech"
 	"github.com/metacubex/mihomo/component/proxydialer"
-	"github.com/metacubex/mihomo/component/resolver"
 	tlsC "github.com/metacubex/mihomo/component/tls"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/ntp"
@@ -330,13 +329,8 @@ func (v *Vmess) DialContextWithDialer(ctx context.Context, dialer C.Dialer, meta
 
 // ListenPacketContext implements C.ProxyAdapter
 func (v *Vmess) ListenPacketContext(ctx context.Context, metadata *C.Metadata) (_ C.PacketConn, err error) {
-	// vmess use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = v.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 	var c net.Conn
 	// gun transport
@@ -367,13 +361,8 @@ func (v *Vmess) ListenPacketWithDialer(ctx context.Context, dialer C.Dialer, met
 		}
 	}
 
-	// vmess use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = v.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 
 	c, err := dialer.DialContext(ctx, "tcp", v.addr)
@@ -413,13 +402,8 @@ func (v *Vmess) Close() error {
 
 // ListenPacketOnStreamConn implements C.ProxyAdapter
 func (v *Vmess) ListenPacketOnStreamConn(ctx context.Context, c net.Conn, metadata *C.Metadata) (_ C.PacketConn, err error) {
-	// vmess use stream-oriented udp with a special address, so we need a net.UDPAddr
-	if !metadata.Resolved() {
-		ip, err := resolver.ResolveIP(ctx, metadata.Host)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = v.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 
 	if pc, ok := c.(net.PacketConn); ok {

adapter/outbound/wireguard.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/base64"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"net"
 	"net/netip"
@@ -520,16 +519,8 @@ func (w *WireGuard) ListenPacketContext(ctx context.Context, metadata *C.Metadat
 	if err = w.init(ctx); err != nil {
 		return nil, err
 	}
-	if (!metadata.Resolved() || w.resolver != nil) && metadata.Host != "" {
-		r := resolver.DefaultResolver
-		if w.resolver != nil {
-			r = w.resolver
-		}
-		ip, err := resolver.ResolveIPWithResolver(ctx, metadata.Host, r)
-		if err != nil {
-			return nil, errors.New("can't resolve ip")
-		}
-		metadata.DstIP = ip
+	if err = w.ResolveUDP(ctx, metadata); err != nil {
+		return nil, err
 	}
 	pc, err = w.tunDevice.ListenPacket(ctx, M.SocksaddrFrom(metadata.DstIP, metadata.DstPort).Unwrap())
 	if err != nil {
@@ -541,6 +532,21 @@ func (w *WireGuard) ListenPacketContext(ctx context.Context, metadata *C.Metadat
 	return newPacketConn(pc, w), nil
 }
 
+func (w *WireGuard) ResolveUDP(ctx context.Context, metadata *C.Metadata) error {
+	if (!metadata.Resolved() || w.resolver != nil) && metadata.Host != "" {
+		r := resolver.DefaultResolver
+		if w.resolver != nil {
+			r = w.resolver
+		}
+		ip, err := resolver.ResolveIPWithResolver(ctx, metadata.Host, r)
+		if err != nil {
+			return fmt.Errorf("can't resolve ip: %w", err)
+		}
+		metadata.DstIP = ip
+	}
+	return nil
+}
+
 // IsL3Protocol implements C.ProxyAdapter
 func (w *WireGuard) IsL3Protocol(metadata *C.Metadata) bool {
 	return true