Remove token field in VMess UDP

proxy/vmess/protocol/udp.go

@@ -16,7 +16,6 @@ import (
 type VMessUDP struct {
 	user    user.ID
 	version byte
-	token   uint16
 	address v2net.Address
 	data    []byte
 }
@@ -51,26 +50,25 @@ func ReadVMessUDP(buffer []byte, userset user.UserSet) (*VMessUDP, error) {
 	vmess := &VMessUDP{
 		user:    *userId,
 		version: buffer[0],
-		token:   binary.BigEndian.Uint16(buffer[1:3]),
 	}
 
-	// buffer[3] is reserved
+	// buffer[1] is reserved
 
-	port := binary.BigEndian.Uint16(buffer[4:6])
+	port := binary.BigEndian.Uint16(buffer[2:4])
-	addrType := buffer[6]
+	addrType := buffer[4]
 	var address v2net.Address
 	switch addrType {
 	case addrTypeIPv4:
-		address = v2net.IPAddress(buffer[7:11], port)
+		address = v2net.IPAddress(buffer[5:9], port)
-		buffer = buffer[11:]
+		buffer = buffer[9:]
 	case addrTypeIPv6:
-		address = v2net.IPAddress(buffer[7:23], port)
+		address = v2net.IPAddress(buffer[5:21], port)
-		buffer = buffer[23:]
+		buffer = buffer[21:]
 	case addrTypeDomain:
-		domainLength := buffer[7]
+		domainLength := buffer[5]
-		domain := string(buffer[8 : 8+domainLength])
+		domain := string(buffer[6 : 6+domainLength])
 		address = v2net.DomainAddress(domain, port)
-		buffer = buffer[8+domainLength:]
+		buffer = buffer[6+domainLength:]
 	default:
 		log.Warning("Unexpected address type %d", addrType)
 		return nil, errors.NewCorruptedPacketError()
@@ -99,7 +97,6 @@ func (vmess *VMessUDP) ToBytes(idHash user.CounterHash, randomRangeInt64 user.Ra
 	fnvHashBegin := 20
 
 	buffer = append(buffer, vmess.version)
-	buffer = append(buffer, byte(vmess.token>>8), byte(vmess.token))
 	buffer = append(buffer, byte(0x00))
 	buffer = append(buffer, vmess.address.PortBytes()...)
 	switch {

proxy/vmess/protocol/udp_test.go

@@ -21,7 +21,6 @@ func TestVMessUDPReadWrite(t *testing.T) {
 	message := &VMessUDP{
 		user:    userId,
 		version: byte(0x01),
-		token:   1234,
 		address: v2net.DomainAddress("v2ray.com", 8372),
 		data:    []byte("An UDP message."),
 	}
@@ -37,7 +36,6 @@ func TestVMessUDPReadWrite(t *testing.T) {
 
 	assert.String(messageRestored.user.String).Equals(message.user.String)
 	assert.Byte(messageRestored.version).Equals(message.version)
-	assert.Uint16(messageRestored.token).Equals(message.token)
 	assert.String(messageRestored.address.String()).Equals(message.address.String())
 	assert.Bytes(messageRestored.data).Equals(message.data)
 }

spec/vmess.md

@@ -49,7 +49,6 @@ UDP 数据包为对称设计，即请求和响应的格式一样
 * 16 字节：基于时间的 hash(用户 [ID](https://github.com/V2Ray/v2ray-core/blob/master/spec/id.md))，见下文
 * 4 字节：余下所有内容的 FNV1a hash
 * 1 字节：版本号，目前为 0x1
-* 2 字节：Token，用于区分数据包
 * 1 字节：保留，暂为 0x00
 * 2 字节：目标端口
 * 1 字节：目标类型