chore: embed hysteria, clean irrelevant codes, code from https://github.com/HyNetwork/hysteria

transport/hysteria/core/protocol.go

@@ -0,0 +1,76 @@
+package core
+
+import (
+	"time"
+)
+
+const (
+	protocolVersion   = uint8(3)
+	protocolVersionV2 = uint8(2)
+	protocolTimeout   = 10 * time.Second
+
+	closeErrorCodeGeneric  = 0
+	closeErrorCodeProtocol = 1
+	closeErrorCodeAuth     = 2
+)
+
+type transmissionRate struct {
+	SendBPS uint64
+	RecvBPS uint64
+}
+
+type clientHello struct {
+	Rate    transmissionRate
+	AuthLen uint16 `struc:"sizeof=Auth"`
+	Auth    []byte
+}
+
+type serverHello struct {
+	OK         bool
+	Rate       transmissionRate
+	MessageLen uint16 `struc:"sizeof=Message"`
+	Message    string
+}
+
+type clientRequest struct {
+	UDP     bool
+	HostLen uint16 `struc:"sizeof=Host"`
+	Host    string
+	Port    uint16
+}
+
+type serverResponse struct {
+	OK           bool
+	UDPSessionID uint32
+	MessageLen   uint16 `struc:"sizeof=Message"`
+	Message      string
+}
+
+type udpMessage struct {
+	SessionID uint32
+	HostLen   uint16 `struc:"sizeof=Host"`
+	Host      string
+	Port      uint16
+	MsgID     uint16 // doesn't matter when not fragmented, but must not be 0 when fragmented
+	FragID    uint8  // doesn't matter when not fragmented, starts at 0 when fragmented
+	FragCount uint8  // must be 1 when not fragmented
+	DataLen   uint16 `struc:"sizeof=Data"`
+	Data      []byte
+}
+
+func (m udpMessage) HeaderSize() int {
+	return 4 + 2 + len(m.Host) + 2 + 2 + 1 + 1 + 2
+}
+
+func (m udpMessage) Size() int {
+	return m.HeaderSize() + len(m.Data)
+}
+
+type udpMessageV2 struct {
+	SessionID uint32
+	HostLen   uint16 `struc:"sizeof=Host"`
+	Host      string
+	Port      uint16
+	DataLen   uint16 `struc:"sizeof=Data"`
+	Data      []byte
+}