Wireguard resolve strategy (#2717)

* 增加 wireguard 出站选项 `resolveStrategy`.

* They become a part of you.

* 移除不必要的选项别名.

* aliases NG.

* 微调.

---------

Co-authored-by: rui0572 <125641819+rui0572@users.noreply.github.com>

infra/conf/wireguard.go

@@ -3,6 +3,7 @@ package conf
 import (
 	"encoding/base64"
 	"encoding/hex"
+	"strings"
 
 	"github.com/xtls/xray-core/proxy/wireguard"
 	"google.golang.org/protobuf/proto"
@@ -53,6 +54,7 @@ type WireGuardConfig struct {
 	MTU            int                    `json:"mtu"`
 	NumWorkers     int                    `json:"workers"`
 	Reserved       []byte                 `json:"reserved"`
+	DomainStrategy string                 `json:"domainStrategy"`
 }
 
 func (c *WireGuardConfig) Build() (proto.Message, error) {
@@ -96,6 +98,21 @@ func (c *WireGuardConfig) Build() (proto.Message, error) {
 	}
 	config.Reserved = c.Reserved
 
+	switch strings.ToLower(c.DomainStrategy) {
+	case "forceip", "":
+		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP
+	case "forceipv4":
+		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP4
+	case "forceipv6":
+		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP6
+	case "forceipv4v6":
+		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP46
+	case "forceipv6v4":
+		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP64
+	default:
+		return nil, newError("unsupported domain strategy: ", c.DomainStrategy)
+	}
+
 	return config, nil
 }
 

infra/conf/wireguard_test.go

@@ -24,7 +24,8 @@ func TestWireGuardOutbound(t *testing.T) {
 					}
 				],
 				"mtu": 1300,
-				"workers": 2
+				"workers": 2,
+				"domainStrategy": "ForceIPv6v4"
 			}`,
 			Parser: loadJSON(creator),
 			Output: &wireguard.DeviceConfig{
@@ -43,6 +44,7 @@ func TestWireGuardOutbound(t *testing.T) {
 				},
 				Mtu:            1300,
 				NumWorkers:     2,
+				DomainStrategy: wireguard.DeviceConfig_FORCE_IP64,
 			},
 		},
 	})

proxy/wireguard/config.go

@@ -0,0 +1,25 @@
+package wireguard
+
+func (c *DeviceConfig) preferIP4() bool {
+	return c.DomainStrategy == DeviceConfig_FORCE_IP ||
+		c.DomainStrategy == DeviceConfig_FORCE_IP4 ||
+		c.DomainStrategy == DeviceConfig_FORCE_IP46
+}
+
+func (c *DeviceConfig) preferIP6() bool {
+	return c.DomainStrategy == DeviceConfig_FORCE_IP ||
+		c.DomainStrategy == DeviceConfig_FORCE_IP6 ||
+		c.DomainStrategy == DeviceConfig_FORCE_IP64
+}
+
+func (c *DeviceConfig) hasFallback() bool {
+	return c.DomainStrategy == DeviceConfig_FORCE_IP46 || c.DomainStrategy == DeviceConfig_FORCE_IP64
+}
+
+func (c *DeviceConfig) fallbackIP4() bool {
+	return c.DomainStrategy == DeviceConfig_FORCE_IP64
+}
+
+func (c *DeviceConfig) fallbackIP6() bool {
+	return c.DomainStrategy == DeviceConfig_FORCE_IP46
+}

proxy/wireguard/config.pb.go

@@ -20,6 +20,61 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
+type DeviceConfig_DomainStrategy int32
+
+const (
+	DeviceConfig_FORCE_IP   DeviceConfig_DomainStrategy = 0
+	DeviceConfig_FORCE_IP4  DeviceConfig_DomainStrategy = 1
+	DeviceConfig_FORCE_IP6  DeviceConfig_DomainStrategy = 2
+	DeviceConfig_FORCE_IP46 DeviceConfig_DomainStrategy = 3
+	DeviceConfig_FORCE_IP64 DeviceConfig_DomainStrategy = 4
+)
+
+// Enum value maps for DeviceConfig_DomainStrategy.
+var (
+	DeviceConfig_DomainStrategy_name = map[int32]string{
+		0: "FORCE_IP",
+		1: "FORCE_IP4",
+		2: "FORCE_IP6",
+		3: "FORCE_IP46",
+		4: "FORCE_IP64",
+	}
+	DeviceConfig_DomainStrategy_value = map[string]int32{
+		"FORCE_IP":   0,
+		"FORCE_IP4":  1,
+		"FORCE_IP6":  2,
+		"FORCE_IP46": 3,
+		"FORCE_IP64": 4,
+	}
+)
+
+func (x DeviceConfig_DomainStrategy) Enum() *DeviceConfig_DomainStrategy {
+	p := new(DeviceConfig_DomainStrategy)
+	*p = x
+	return p
+}
+
+func (x DeviceConfig_DomainStrategy) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (DeviceConfig_DomainStrategy) Descriptor() protoreflect.EnumDescriptor {
+	return file_proxy_wireguard_config_proto_enumTypes[0].Descriptor()
+}
+
+func (DeviceConfig_DomainStrategy) Type() protoreflect.EnumType {
+	return &file_proxy_wireguard_config_proto_enumTypes[0]
+}
+
+func (x DeviceConfig_DomainStrategy) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Use DeviceConfig_DomainStrategy.Descriptor instead.
+func (DeviceConfig_DomainStrategy) EnumDescriptor() ([]byte, []int) {
+	return file_proxy_wireguard_config_proto_rawDescGZIP(), []int{1, 0}
+}
+
 type PeerConfig struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -110,6 +165,7 @@ type DeviceConfig struct {
 	Mtu            int32                       `protobuf:"varint,4,opt,name=mtu,proto3" json:"mtu,omitempty"`
 	NumWorkers     int32                       `protobuf:"varint,5,opt,name=num_workers,json=numWorkers,proto3" json:"num_workers,omitempty"`
 	Reserved       []byte                      `protobuf:"bytes,6,opt,name=reserved,proto3" json:"reserved,omitempty"`
+	DomainStrategy DeviceConfig_DomainStrategy `protobuf:"varint,7,opt,name=domain_strategy,json=domainStrategy,proto3,enum=xray.proxy.wireguard.DeviceConfig_DomainStrategy" json:"domain_strategy,omitempty"`
 }
 
 func (x *DeviceConfig) Reset() {
@@ -186,6 +242,13 @@ func (x *DeviceConfig) GetReserved() []byte {
 	return nil
 }
 
+func (x *DeviceConfig) GetDomainStrategy() DeviceConfig_DomainStrategy {
+	if x != nil {
+		return x.DomainStrategy
+	}
+	return DeviceConfig_FORCE_IP
+}
+
 var File_proxy_wireguard_config_proto protoreflect.FileDescriptor
 
 var file_proxy_wireguard_config_proto_rawDesc = []byte{
@@ -203,7 +266,7 @@ var file_proxy_wireguard_config_proto_rawDesc = []byte{
 	0x76, 0x65, 0x18, 0x04, 0x20, 0x01, 0x28, 0x05, 0x52, 0x09, 0x6b, 0x65, 0x65, 0x70, 0x41, 0x6c,
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 	0x6f, 0x6e, 0x66, 0x69, 0x67, 0x12, 0x1d, 0x0a, 0x0a, 0x73, 0x65, 0x63, 0x72, 0x65, 0x74, 0x5f,
 	0x6b, 0x65, 0x79, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x09, 0x73, 0x65, 0x63, 0x72, 0x65,
 	0x74, 0x4b, 0x65, 0x79, 0x12, 0x1a, 0x0a, 0x08, 0x65, 0x6e, 0x64, 0x70, 0x6f, 0x69, 0x6e, 0x74,
@@ -216,13 +279,25 @@ var file_proxy_wireguard_config_proto_rawDesc = []byte{
 	0x6d, 0x5f, 0x77, 0x6f, 0x72, 0x6b, 0x65, 0x72, 0x73, 0x18, 0x05, 0x20, 0x01, 0x28, 0x05, 0x52,
 	0x0a, 0x6e, 0x75, 0x6d, 0x57, 0x6f, 0x72, 0x6b, 0x65, 0x72, 0x73, 0x12, 0x1a, 0x0a, 0x08, 0x72,
 	0x65, 0x73, 0x65, 0x72, 0x76, 0x65, 0x64, 0x18, 0x06, 0x20, 0x01, 0x28, 0x0c, 0x52, 0x08, 0x72,
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-	0x72, 0x61, 0x79, 0x2e, 0x70, 0x72, 0x6f, 0x78, 0x79, 0x2e, 0x77, 0x69, 0x72, 0x65, 0x67, 0x75,
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+	0x64, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -237,18 +312,21 @@ func file_proxy_wireguard_config_proto_rawDescGZIP() []byte {
 	return file_proxy_wireguard_config_proto_rawDescData
 }
 
+var file_proxy_wireguard_config_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
 var file_proxy_wireguard_config_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
 var file_proxy_wireguard_config_proto_goTypes = []interface{}{
-	(*PeerConfig)(nil),   // 0: xray.proxy.wireguard.PeerConfig
-	(*DeviceConfig)(nil), // 1: xray.proxy.wireguard.DeviceConfig
+	(DeviceConfig_DomainStrategy)(0), // 0: xray.proxy.wireguard.DeviceConfig.DomainStrategy
+	(*PeerConfig)(nil),               // 1: xray.proxy.wireguard.PeerConfig
+	(*DeviceConfig)(nil),             // 2: xray.proxy.wireguard.DeviceConfig
 }
 var file_proxy_wireguard_config_proto_depIdxs = []int32{
-	0, // 0: xray.proxy.wireguard.DeviceConfig.peers:type_name -> xray.proxy.wireguard.PeerConfig
-	1, // [1:1] is the sub-list for method output_type
-	1, // [1:1] is the sub-list for method input_type
-	1, // [1:1] is the sub-list for extension type_name
-	1, // [1:1] is the sub-list for extension extendee
-	0, // [0:1] is the sub-list for field type_name
+	1, // 0: xray.proxy.wireguard.DeviceConfig.peers:type_name -> xray.proxy.wireguard.PeerConfig
+	0, // 1: xray.proxy.wireguard.DeviceConfig.domain_strategy:type_name -> xray.proxy.wireguard.DeviceConfig.DomainStrategy
+	2, // [2:2] is the sub-list for method output_type
+	2, // [2:2] is the sub-list for method input_type
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
 }
 
 func init() { file_proxy_wireguard_config_proto_init() }
@@ -287,13 +365,14 @@ func file_proxy_wireguard_config_proto_init() {
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_proxy_wireguard_config_proto_rawDesc,
-			NumEnums:      0,
+			NumEnums:      1,
 			NumMessages:   2,
 			NumExtensions: 0,
 			NumServices:   0,
 		},
 		GoTypes:           file_proxy_wireguard_config_proto_goTypes,
 		DependencyIndexes: file_proxy_wireguard_config_proto_depIdxs,
+		EnumInfos:         file_proxy_wireguard_config_proto_enumTypes,
 		MessageInfos:      file_proxy_wireguard_config_proto_msgTypes,
 	}.Build()
 	File_proxy_wireguard_config_proto = out.File

proxy/wireguard/config.proto

@@ -15,10 +15,18 @@ message PeerConfig {
 }
 
 message DeviceConfig {
+    enum DomainStrategy {
+        FORCE_IP = 0;
+        FORCE_IP4 = 1;
+        FORCE_IP6 = 2;
+        FORCE_IP46 = 3;
+        FORCE_IP64 = 4;
+    }
     string secret_key = 1;
     repeated string endpoint = 2;
     repeated PeerConfig peers = 3;
     int32 mtu = 4;
     int32 num_workers = 5;
     bytes reserved = 6;
+    DomainStrategy domain_strategy = 7;
 }

proxy/wireguard/wireguard.go

@@ -31,6 +31,7 @@ import (
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/buf"
+	"github.com/xtls/xray-core/common/dice"
 	"github.com/xtls/xray-core/common/log"
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
@@ -159,15 +160,23 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 	addr := destination.Address
 	if addr.Family().IsDomain() {
 		ips, err := h.dns.LookupIP(addr.Domain(), dns.IPOption{
-			IPv4Enable: h.hasIPv4,
-			IPv6Enable: h.hasIPv6,
+			IPv4Enable: h.hasIPv4 && h.conf.preferIP4(),
+			IPv6Enable: h.hasIPv6 && h.conf.preferIP6(),
 		})
+		{ // Resolve fallback
+			if (len(ips) == 0 || err != nil) && h.conf.hasFallback() {
+				ips, err = h.dns.LookupIP(addr.Domain(), dns.IPOption{
+					IPv4Enable: h.hasIPv4 && h.conf.fallbackIP4(),
+					IPv6Enable: h.hasIPv6 && h.conf.fallbackIP6(),
+				})
+			}
+		}
 		if err != nil {
 			return newError("failed to lookup DNS").Base(err)
 		} else if len(ips) == 0 {
 			return dns.ErrEmptyResponse
 		}
-		addr = net.IPAddress(ips[0])
+		addr = net.IPAddress(ips[dice.Roll(len(ips))])
 	}
 
 	var newCtx context.Context