chore: cleanup resolveUDPAddr code

adapter/outbound/hysteria.go

@@ -78,7 +78,7 @@ func (h *Hysteria) genHdc(ctx context.Context, opts ...dialer.Option) utils.Pack
 			return cDialer.ListenPacket(ctx, network, "", rAddrPort)
 		},
 		remoteAddr: func(addr string) (net.Addr, error) {
-			return resolveUDPAddrWithPrefer(ctx, "udp", addr, h.prefer)
+			return resolveUDPAddr(ctx, "udp", addr, h.prefer)
 		},
 	}
 }

adapter/outbound/hysteria2.go

@@ -171,7 +171,7 @@ func NewHysteria2(option Hysteria2Option) (*Hysteria2, error) {
 		CWND:               option.CWND,
 		UdpMTU:             option.UdpMTU,
 		ServerAddress: func(ctx context.Context) (*net.UDPAddr, error) {
-			return resolveUDPAddrWithPrefer(ctx, "udp", addr, C.NewDNSPrefer(option.IPVersion))
+			return resolveUDPAddr(ctx, "udp", addr, C.NewDNSPrefer(option.IPVersion))
 		},
 	}
 
@@ -188,7 +188,7 @@ func NewHysteria2(option Hysteria2Option) (*Hysteria2, error) {
 		})
 		if len(serverAddress) > 0 {
 			clientOptions.ServerAddress = func(ctx context.Context) (*net.UDPAddr, error) {
-				return resolveUDPAddrWithPrefer(ctx, "udp", serverAddress[randv2.IntN(len(serverAddress))], C.NewDNSPrefer(option.IPVersion))
+				return resolveUDPAddr(ctx, "udp", serverAddress[randv2.IntN(len(serverAddress))], C.NewDNSPrefer(option.IPVersion))
 			}
 
 			if option.HopInterval == 0 {

adapter/outbound/shadowsocks.go

@@ -197,7 +197,7 @@ func (ss *ShadowSocks) ListenPacketWithDialer(ctx context.Context, dialer C.Dial
 			return nil, err
 		}
 	}
-	addr, err := resolveUDPAddrWithPrefer(ctx, "udp", ss.addr, ss.prefer)
+	addr, err := resolveUDPAddr(ctx, "udp", ss.addr, ss.prefer)
 	if err != nil {
 		return nil, err
 	}

adapter/outbound/shadowsocksr.go

@@ -102,7 +102,7 @@ func (ssr *ShadowSocksR) ListenPacketWithDialer(ctx context.Context, dialer C.Di
 			return nil, err
 		}
 	}
-	addr, err := resolveUDPAddrWithPrefer(ctx, "udp", ssr.addr, ssr.prefer)
+	addr, err := resolveUDPAddr(ctx, "udp", ssr.addr, ssr.prefer)
 	if err != nil {
 		return nil, err
 	}

adapter/outbound/socks5.go

@@ -147,7 +147,7 @@ func (ss *Socks5) ListenPacketContext(ctx context.Context, metadata *C.Metadata,
 		err = errors.New("invalid UDP bind address")
 		return
 	} else if bindUDPAddr.IP.IsUnspecified() {
-		serverAddr, err := resolveUDPAddr(ctx, "udp", ss.Addr())
+		serverAddr, err := resolveUDPAddr(ctx, "udp", ss.Addr(), C.IPv4Prefer)
 		if err != nil {
 			return nil, err
 		}

adapter/outbound/tuic.go

@@ -130,7 +130,7 @@ func (t *Tuic) dialWithDialer(ctx context.Context, dialer C.Dialer) (transport *
 			return nil, nil, err
 		}
 	}
-	udpAddr, err := resolveUDPAddrWithPrefer(ctx, "udp", t.addr, t.prefer)
+	udpAddr, err := resolveUDPAddr(ctx, "udp", t.addr, t.prefer)
 	if err != nil {
 		return nil, nil, err
 	}

adapter/outbound/util.go

@@ -3,31 +3,17 @@ package outbound
 import (
 	"bytes"
 	"context"
-	"crypto/tls"
 	"fmt"
 	"net"
 	"net/netip"
 	"regexp"
 	"strconv"
-	"sync"
 
 	"github.com/metacubex/mihomo/component/resolver"
 	C "github.com/metacubex/mihomo/constant"
 	"github.com/metacubex/mihomo/transport/socks5"
 )
 
-var (
-	globalClientSessionCache tls.ClientSessionCache
-	once                     sync.Once
-)
-
-func getClientSessionCache() tls.ClientSessionCache {
-	once.Do(func() {
-		globalClientSessionCache = tls.NewLRUClientSessionCache(128)
-	})
-	return globalClientSessionCache
-}
-
 func serializesSocksAddr(metadata *C.Metadata) []byte {
 	var buf [][]byte
 	addrType := metadata.AddrType()
@@ -49,67 +35,21 @@ func serializesSocksAddr(metadata *C.Metadata) []byte {
 	return bytes.Join(buf, nil)
 }
 
-func resolveUDPAddr(ctx context.Context, network, address string) (*net.UDPAddr, error) {
+func resolveUDPAddr(ctx context.Context, network, address string, prefer C.DNSPrefer) (*net.UDPAddr, error) {
-	host, port, err := net.SplitHostPort(address)
-	if err != nil {
-		return nil, err
-	}
-
-	ip, err := resolver.ResolveIPWithResolver(ctx, host, resolver.ProxyServerHostResolver)
-	if err != nil {
-		return nil, err
-	}
-	return net.ResolveUDPAddr(network, net.JoinHostPort(ip.String(), port))
-}
-
-func resolveUDPAddrWithPrefer(ctx context.Context, network, address string, prefer C.DNSPrefer) (*net.UDPAddr, error) {
 	host, port, err := net.SplitHostPort(address)
 	if err != nil {
 		return nil, err
 	}
 	var ip netip.Addr
-	var fallback netip.Addr
 	switch prefer {
 	case C.IPv4Only:
 		ip, err = resolver.ResolveIPv4WithResolver(ctx, host, resolver.ProxyServerHostResolver)
 	case C.IPv6Only:
 		ip, err = resolver.ResolveIPv6WithResolver(ctx, host, resolver.ProxyServerHostResolver)
 	case C.IPv6Prefer:
-		var ips []netip.Addr
+		ip, err = resolver.ResolveIPPrefer6WithResolver(ctx, host, resolver.ProxyServerHostResolver)
-		ips, err = resolver.LookupIPWithResolver(ctx, host, resolver.ProxyServerHostResolver)
-		if err == nil {
-			for _, addr := range ips {
-				if addr.Is6() {
-					ip = addr
-					break
-				} else {
-					if !fallback.IsValid() {
-						fallback = addr
-					}
-				}
-			}
-		}
 	default:
-		// C.IPv4Prefer, C.DualStack and other
+		ip, err = resolver.ResolveIPWithResolver(ctx, host, resolver.ProxyServerHostResolver)
-		var ips []netip.Addr
-		ips, err = resolver.LookupIPWithResolver(ctx, host, resolver.ProxyServerHostResolver)
-		if err == nil {
-			for _, addr := range ips {
-				if addr.Is4() {
-					ip = addr
-					break
-				} else {
-					if !fallback.IsValid() {
-						fallback = addr
-					}
-				}
-			}
-
-		}
-	}
-
-	if !ip.IsValid() && fallback.IsValid() {
-		ip = fallback
 	}
 
 	if err != nil {

adapter/outbound/wireguard.go

@@ -301,7 +301,7 @@ func (w *WireGuard) resolve(ctx context.Context, address M.Socksaddr) (netip.Add
 	if address.Addr.IsValid() {
 		return address.AddrPort(), nil
 	}
-	udpAddr, err := resolveUDPAddrWithPrefer(ctx, "udp", address.String(), w.prefer)
+	udpAddr, err := resolveUDPAddr(ctx, "udp", address.String(), w.prefer)
 	if err != nil {
 		return netip.AddrPort{}, err
 	}

component/resolver/resolver.go

@@ -196,6 +196,26 @@ func ResolveIP(ctx context.Context, host string) (netip.Addr, error) {
 	return ResolveIPWithResolver(ctx, host, DefaultResolver)
 }
 
+// ResolveIPPrefer6WithResolver same as ResolveIP, but with a resolver
+func ResolveIPPrefer6WithResolver(ctx context.Context, host string, r Resolver) (netip.Addr, error) {
+	ips, err := LookupIPWithResolver(ctx, host, r)
+	if err != nil {
+		return netip.Addr{}, err
+	} else if len(ips) == 0 {
+		return netip.Addr{}, fmt.Errorf("%w: %s", ErrIPNotFound, host)
+	}
+	ipv4s, ipv6s := SortationAddr(ips)
+	if len(ipv6s) > 0 {
+		return ipv6s[randv2.IntN(len(ipv6s))], nil
+	}
+	return ipv4s[randv2.IntN(len(ipv4s))], nil
+}
+
+// ResolveIPPrefer6 with a host, return ip and priority return TypeAAAA
+func ResolveIPPrefer6(ctx context.Context, host string) (netip.Addr, error) {
+	return ResolveIPPrefer6WithResolver(ctx, host, DefaultResolver)
+}
+
 func ResetConnection() {
 	if DefaultResolver != nil {
 		go DefaultResolver.ResetConnection()