support client subnet

app/dns/config.pb.go

@@ -19,19 +19,21 @@ const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 type Config struct {
 	// Nameservers used by this DNS. Only traditional UDP servers are support at the moment.
 	// A special value 'localhost' as a domain address can be set to use DNS on local system.
-	NameServers []*net.Endpoint `protobuf:"bytes,1,rep,name=NameServers" json:"NameServers,omitempty"`
+	NameServers []*net.Endpoint `protobuf:"bytes,1,rep,name=NameServers,proto3" json:"NameServers,omitempty"`
 	// Static hosts. Domain to IP.
-	Hosts                map[string]*net.IPOrDomain `protobuf:"bytes,2,rep,name=Hosts" json:"Hosts,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
-	XXX_NoUnkeyedLiteral struct{}                   `json:"-"`
-	XXX_unrecognized     []byte                     `json:"-"`
-	XXX_sizecache        int32                      `json:"-"`
+	Hosts map[string]*net.IPOrDomain `protobuf:"bytes,2,rep,name=Hosts,proto3" json:"Hosts,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+	// Client IP for EDNS client subnet.
+	ClientIp             *Config_ClientIP `protobuf:"bytes,3,opt,name=client_ip,json=clientIp,proto3" json:"client_ip,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}         `json:"-"`
+	XXX_unrecognized     []byte           `json:"-"`
+	XXX_sizecache        int32            `json:"-"`
 }
 
 func (m *Config) Reset()         { *m = Config{} }
 func (m *Config) String() string { return proto.CompactTextString(m) }
 func (*Config) ProtoMessage()    {}
 func (*Config) Descriptor() ([]byte, []int) {
-	return fileDescriptor_config_862435acfeec6b70, []int{0}
+	return fileDescriptor_config_209d2630698ab6f5, []int{0}
 }
 func (m *Config) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Config.Unmarshal(m, b)
@@ -65,33 +67,93 @@ func (m *Config) GetHosts() map[string]*net.IPOrDomain {
 	return nil
 }
 
+func (m *Config) GetClientIp() *Config_ClientIP {
+	if m != nil {
+		return m.ClientIp
+	}
+	return nil
+}
+
+type Config_ClientIP struct {
+	// IPv4 address of the client. Must be 4 bytes.
+	V4 []byte `protobuf:"bytes,1,opt,name=v4,proto3" json:"v4,omitempty"`
+	// IPv6 address of the client. Must be 4 bytes.
+	V6                   []byte   `protobuf:"bytes,2,opt,name=v6,proto3" json:"v6,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Config_ClientIP) Reset()         { *m = Config_ClientIP{} }
+func (m *Config_ClientIP) String() string { return proto.CompactTextString(m) }
+func (*Config_ClientIP) ProtoMessage()    {}
+func (*Config_ClientIP) Descriptor() ([]byte, []int) {
+	return fileDescriptor_config_209d2630698ab6f5, []int{0, 1}
+}
+func (m *Config_ClientIP) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_Config_ClientIP.Unmarshal(m, b)
+}
+func (m *Config_ClientIP) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_Config_ClientIP.Marshal(b, m, deterministic)
+}
+func (dst *Config_ClientIP) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Config_ClientIP.Merge(dst, src)
+}
+func (m *Config_ClientIP) XXX_Size() int {
+	return xxx_messageInfo_Config_ClientIP.Size(m)
+}
+func (m *Config_ClientIP) XXX_DiscardUnknown() {
+	xxx_messageInfo_Config_ClientIP.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Config_ClientIP proto.InternalMessageInfo
+
+func (m *Config_ClientIP) GetV4() []byte {
+	if m != nil {
+		return m.V4
+	}
+	return nil
+}
+
+func (m *Config_ClientIP) GetV6() []byte {
+	if m != nil {
+		return m.V6
+	}
+	return nil
+}
+
 func init() {
 	proto.RegisterType((*Config)(nil), "v2ray.core.app.dns.Config")
 	proto.RegisterMapType((map[string]*net.IPOrDomain)(nil), "v2ray.core.app.dns.Config.HostsEntry")
+	proto.RegisterType((*Config_ClientIP)(nil), "v2ray.core.app.dns.Config.ClientIP")
 }
 
 func init() {
-	proto.RegisterFile("v2ray.com/core/app/dns/config.proto", fileDescriptor_config_862435acfeec6b70)
-}
-
-var fileDescriptor_config_862435acfeec6b70 = []byte{
-	// 286 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x74, 0x90, 0x41, 0x4b, 0x33, 0x31,
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-	0xbd, 0x85, 0xe4, 0x79, 0xf2, 0xbe, 0x33, 0x7c, 0xaf, 0x29, 0xbc, 0x6a, 0xa1, 0x22, 0x2b, 0x2b,
-	0xf2, 0x46, 0x2a, 0xe7, 0xa4, 0xc6, 0x20, 0x2b, 0xc2, 0xa7, 0xfa, 0x19, 0x9c, 0xa7, 0x48, 0x42,
-	0x7c, 0x41, 0xde, 0x80, 0x72, 0x0e, 0x34, 0x86, 0xd1, 0xc1, 0x0f, 0xb1, 0x22, 0x6b, 0x09, 0x25,
-	0x9a, 0x28, 0x95, 0xd6, 0xde, 0x84, 0x90, 0xe4, 0xd1, 0xe1, 0x66, 0x50, 0x9b, 0x10, 0x6b, 0x54,
-	0xb1, 0x26, 0x4c, 0xf0, 0xee, 0x07, 0xe3, 0x83, 0x59, 0x17, 0x2d, 0xa6, 0x7c, 0x78, 0xad, 0xac,
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-	0x18, 0xf2, 0xac, 0x93, 0xf7, 0xe1, 0xf7, 0x1c, 0x90, 0xd2, 0xa0, 0xe3, 0x16, 0x18, 0x7d, 0x5b,
-	0x26, 0x67, 0xf4, 0xc0, 0xf9, 0xf7, 0xa5, 0xf8, 0xcf, 0x7b, 0x2f, 0xa6, 0xcd, 0xd9, 0x98, 0x4d,
-	0xfe, 0x95, 0xab, 0xa3, 0x38, 0xe1, 0xfd, 0x46, 0xbd, 0xbe, 0x99, 0x3c, 0x1b, 0xb3, 0xc9, 0xb0,
-	0xd8, 0xd9, 0xd0, 0xec, 0x6a, 0x79, 0xe3, 0xe7, 0x64, 0x55, 0x8d, 0x65, 0xe2, 0xcf, 0xb2, 0x53,
-	0x76, 0x71, 0xcc, 0xb7, 0x2a, 0xb2, 0x7f, 0xf4, 0x59, 0xb2, 0xfb, 0x9e, 0xc6, 0xf0, 0x9e, 0x89,
-	0xbb, 0xa2, 0x54, 0x2d, 0xcc, 0x56, 0x6f, 0x53, 0xe7, 0x60, 0x8e, 0xe1, 0x71, 0xd0, 0x2d, 0xe9,
-	0xe8, 0x33, 0x00, 0x00, 0xff, 0xff, 0x2d, 0xe1, 0x96, 0x19, 0xb5, 0x01, 0x00, 0x00,
+	proto.RegisterFile("v2ray.com/core/app/dns/config.proto", fileDescriptor_config_209d2630698ab6f5)
+}
+
+var fileDescriptor_config_209d2630698ab6f5 = []byte{
+	// 338 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x7c, 0x91, 0x51, 0x4b, 0xf3, 0x30,
+	0x14, 0x86, 0x69, 0xcb, 0xc6, 0x96, 0x7d, 0x7c, 0x48, 0x2e, 0xa4, 0xf4, 0xc6, 0xe9, 0x10, 0x87,
+	0x42, 0x0a, 0x75, 0x4c, 0xd1, 0x1b, 0xe7, 0x36, 0x70, 0x37, 0x3a, 0x2a, 0x78, 0xa1, 0x17, 0x12,
+	0x9b, 0x28, 0xc1, 0xf5, 0x24, 0x24, 0xb1, 0xd0, 0xbf, 0xe4, 0xdf, 0xf1, 0x0f, 0xc9, 0x12, 0x86,
+	0x43, 0x9d, 0x77, 0x3d, 0xf4, 0x7d, 0x9e, 0xf7, 0x1c, 0x82, 0x7a, 0x55, 0xa6, 0x69, 0x4d, 0x0a,
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+	0x69, 0x69, 0x25, 0xc6, 0xab, 0x90, 0xe6, 0x84, 0x2a, 0x45, 0x18, 0x98, 0xe4, 0xe0, 0x1b, 0x58,
+	0xc8, 0xb2, 0x94, 0x90, 0x02, 0xb7, 0x29, 0x65, 0x4c, 0x73, 0x63, 0x3c, 0x9c, 0x1c, 0x6d, 0x0e,
+	0x32, 0x6e, 0xac, 0x00, 0x6a, 0x85, 0x04, 0x1f, 0xde, 0xfb, 0x08, 0x51, 0x73, 0xec, 0xaa, 0xf1,
+	0x08, 0x75, 0xae, 0x69, 0xc9, 0x6f, 0xb9, 0xae, 0xb8, 0x36, 0x71, 0xd0, 0x8d, 0xfa, 0x9d, 0x6c,
+	0x87, 0xac, 0xad, 0xe2, 0x4d, 0x04, 0xb8, 0x25, 0x53, 0x60, 0x4a, 0x0a, 0xb0, 0xf9, 0x3a, 0x83,
+	0xcf, 0x51, 0xe3, 0x4a, 0x1a, 0x6b, 0xe2, 0xd0, 0xc1, 0xfb, 0xe4, 0xe7, 0x1d, 0xc4, 0xb7, 0x11,
+	0x97, 0x9b, 0x82, 0xd5, 0x75, 0xee, 0x19, 0x7c, 0x81, 0xda, 0xc5, 0x42, 0x70, 0xb0, 0x8f, 0x42,
+	0xc5, 0x51, 0x37, 0xe8, 0x77, 0xb2, 0xde, 0x1f, 0x82, 0xb1, 0xcb, 0xce, 0xe6, 0x79, 0xcb, 0x53,
+	0x33, 0x95, 0x3c, 0x20, 0xf4, 0xa5, 0xc5, 0x5b, 0x28, 0x7a, 0xe5, 0x75, 0x1c, 0x74, 0x83, 0x7e,
+	0x3b, 0x5f, 0x7e, 0xe2, 0x13, 0xd4, 0xa8, 0xe8, 0xe2, 0x8d, 0xc7, 0xa1, 0xb3, 0xef, 0x6e, 0xb8,
+	0x6d, 0x36, 0xbf, 0xd1, 0x13, 0x59, 0x52, 0x01, 0xb9, 0xcf, 0x9f, 0x85, 0xa7, 0x41, 0x72, 0x88,
+	0x5a, 0xab, 0x4a, 0xfc, 0x1f, 0x85, 0xd5, 0xc0, 0x99, 0xff, 0xe5, 0x61, 0x35, 0x70, 0xf3, 0xd0,
+	0x59, 0x97, 0xf3, 0xf0, 0x72, 0x80, 0xb6, 0x0b, 0x59, 0xfe, 0xb2, 0xfc, 0x3c, 0xb8, 0x8f, 0x18,
+	0x98, 0xf7, 0x10, 0xdf, 0x65, 0x39, 0xad, 0xc9, 0x78, 0xf9, 0x6f, 0xa4, 0x14, 0x99, 0x80, 0x79,
+	0x6a, 0xba, 0x27, 0x39, 0xfe, 0x0c, 0x00, 0x00, 0xff, 0xff, 0x55, 0xb0, 0x77, 0x62, 0x23, 0x02,
+	0x00, 0x00,
 }

app/dns/config.proto

@@ -16,4 +16,14 @@ message Config {
 
   // Static hosts. Domain to IP.
   map<string, v2ray.core.common.net.IPOrDomain> Hosts = 2;
+
+  message ClientIP {
+    // IPv4 address of the client. Must be 4 bytes.
+    bytes v4 = 1;
+    // IPv6 address of the client. Must be 4 bytes.
+    bytes v6 = 2;
+  }
+
+  // Client IP for EDNS client subnet.
+  ClientIP client_ip = 3;
 }

app/dns/server.go

@@ -14,8 +14,9 @@ import (
 
 type Server struct {
 	sync.Mutex
-	hosts   map[string]net.IP
-	servers []NameServer
+	hosts    map[string]net.IP
+	servers  []NameServer
+	clientIP *Config_ClientIP
 }
 
 func New(ctx context.Context, config *Config) (*Server, error) {
@@ -23,6 +24,10 @@ func New(ctx context.Context, config *Config) (*Server, error) {
 		servers: make([]NameServer, len(config.NameServers)),
 		hosts:   config.GetInternalHosts(),
 	}
+	if config.ClientIp != nil {
+		server.clientIP = config.ClientIp
+	}
+
 	v := core.MustFromContext(ctx)
 	if err := v.RegisterFeature((*core.DNSClient)(nil), server); err != nil {
 		return nil, newError("unable to register DNSClient.").Base(err)
@@ -38,7 +43,7 @@ func New(ctx context.Context, config *Config) (*Server, error) {
 				dest.Network = net.Network_UDP
 			}
 			if dest.Network == net.Network_UDP {
-				server.servers[idx] = NewClassicNameServer(dest, v.Dispatcher())
+				server.servers[idx] = NewClassicNameServer(dest, v.Dispatcher(), server.clientIP)
 			}
 		}
 	}

app/dns/udpns.go

@@ -37,13 +37,15 @@ type ClassicNameServer struct {
 	udpServer *udp.Dispatcher
 	cleanup   *task.Periodic
 	reqID     uint32
+	clientIP  *Config_ClientIP
 }
 
-func NewClassicNameServer(address net.Destination, dispatcher core.Dispatcher) *ClassicNameServer {
+func NewClassicNameServer(address net.Destination, dispatcher core.Dispatcher, clientIP *Config_ClientIP) *ClassicNameServer {
 	s := &ClassicNameServer{
 		address:   address,
 		ips:       make(map[string][]IPRecord),
 		udpServer: udp.NewDispatcher(dispatcher),
+		clientIP:  clientIP,
 	}
 	s.cleanup = &task.Periodic{
 		Interval: time.Minute,
@@ -134,27 +136,66 @@ func (s *ClassicNameServer) updateIP(domain string, ips []IPRecord) {
 	s.updated.Signal()
 }
 
+func (s *ClassicNameServer) getMsgOptions() *dns.OPT {
+	if s.clientIP == nil {
+		return nil
+	}
+
+	o := new(dns.OPT)
+	o.Hdr.Name = "."
+	o.Hdr.Rrtype = dns.TypeOPT
+
+	if len(s.clientIP.V4) == 4 {
+		e := new(dns.EDNS0_SUBNET)
+		e.Code = dns.EDNS0SUBNET
+		e.Family = 1         // 1 for IPv4 source address, 2 for IPv6
+		e.SourceNetmask = 24 // 32 for IPV4, 128 for IPv6
+		e.SourceScope = 0
+		e.Address = net.IP(s.clientIP.V4)
+		o.Option = append(o.Option, e)
+	}
+
+	if len(s.clientIP.V6) == 16 {
+		e := new(dns.EDNS0_SUBNET)
+		e.Code = dns.EDNS0SUBNET
+		e.Family = 2         // 1 for IPv4 source address, 2 for IPv6
+		e.SourceNetmask = 24 // 32 for IPV4, 128 for IPv6
+		e.SourceScope = 0
+		e.Address = net.IP(s.clientIP.V6)
+		o.Option = append(o.Option, e)
+	}
+
+	return o
+
+}
+
 func (s *ClassicNameServer) buildMsgs(domain string) []*dns.Msg {
 	allowMulti := multiQuestionDNS[s.address.Address]
 
+	qA := dns.Question{
+		Name:   domain,
+		Qtype:  dns.TypeA,
+		Qclass: dns.ClassINET,
+	}
+
+	qAAAA := dns.Question{
+		Name:   domain,
+		Qtype:  dns.TypeAAAA,
+		Qclass: dns.ClassINET,
+	}
+
 	var msgs []*dns.Msg
 
 	{
 		msg := new(dns.Msg)
 		msg.Id = uint16(atomic.AddUint32(&s.reqID, 1))
 		msg.RecursionDesired = true
-		msg.Question = []dns.Question{
-			{
-				Name:   domain,
-				Qtype:  dns.TypeA,
-				Qclass: dns.ClassINET,
-			}}
+		msg.Question = []dns.Question{qA}
 		if allowMulti {
-			msg.Question = append(msg.Question, dns.Question{
-				Name:   domain,
-				Qtype:  dns.TypeAAAA,
-				Qclass: dns.ClassINET,
-			})
+			msg.Question = append(msg.Question, qAAAA)
+		}
+		if opt := s.getMsgOptions(); opt != nil {
+			msg.Extra = append(msg.Extra, opt)
 		}
 		msgs = append(msgs, msg)
 	}
@@ -163,12 +204,9 @@ func (s *ClassicNameServer) buildMsgs(domain string) []*dns.Msg {
 		msg := new(dns.Msg)
 		msg.Id = uint16(atomic.AddUint32(&s.reqID, 1))
 		msg.RecursionDesired = true
-		msg.Question = []dns.Question{
-			{
-				Name:   domain,
-				Qtype:  dns.TypeAAAA,
-				Qclass: dns.ClassINET,
-			},
+		msg.Question = []dns.Question{qAAAA}
+		if opt := s.getMsgOptions(); opt != nil {
+			msg.Extra = append(msg.Extra, opt)
 		}
 		msgs = append(msgs, msg)
 	}