package mux import ( "v2ray.com/core/common/bitmask" "v2ray.com/core/common/buf" "v2ray.com/core/common/net" "v2ray.com/core/common/protocol" "v2ray.com/core/common/serial" ) type SessionStatus byte const ( SessionStatusNew SessionStatus = 0x01 SessionStatusKeep SessionStatus = 0x02 SessionStatusEnd SessionStatus = 0x03 SessionStatusKeepAlive SessionStatus = 0x04 ) const ( OptionData bitmask.Byte = 0x01 OptionError bitmask.Byte = 0x02 ) type TargetNetwork byte const ( TargetNetworkTCP TargetNetwork = 0x01 TargetNetworkUDP TargetNetwork = 0x02 ) var addrParser = protocol.NewAddressParser( protocol.AddressFamilyByte(byte(protocol.AddressTypeIPv4), net.AddressFamilyIPv4), protocol.AddressFamilyByte(byte(protocol.AddressTypeDomain), net.AddressFamilyDomain), protocol.AddressFamilyByte(byte(protocol.AddressTypeIPv6), net.AddressFamilyIPv6), protocol.PortThenAddress(), ) /* Frame format 2 bytes - length 2 bytes - session id 1 bytes - status 1 bytes - option 1 byte - network 2 bytes - port n bytes - address */ type FrameMetadata struct { Target net.Destination SessionID uint16 Option bitmask.Byte SessionStatus SessionStatus } func (f FrameMetadata) WriteTo(b *buf.Buffer) error { lenBytes := b.Bytes() b.AppendBytes(0x00, 0x00) len0 := b.Len() if err := b.AppendSupplier(serial.WriteUint16(f.SessionID)); err != nil { return err } b.AppendBytes(byte(f.SessionStatus), byte(f.Option)) if f.SessionStatus == SessionStatusNew { switch f.Target.Network { case net.Network_TCP: b.AppendBytes(byte(TargetNetworkTCP)) case net.Network_UDP: b.AppendBytes(byte(TargetNetworkUDP)) } if err := addrParser.WriteAddressPort(b, f.Target.Address, f.Target.Port); err != nil { return err } } len1 := b.Len() serial.Uint16ToBytes(uint16(len1-len0), lenBytes) return nil } func ReadFrameFrom(b *buf.Buffer) (*FrameMetadata, error) { if b.Len() < 4 { return nil, newError("insufficient buffer: ", b.Len()) } f := &FrameMetadata{ SessionID: serial.BytesToUint16(b.BytesTo(2)), SessionStatus: SessionStatus(b.Byte(2)), Option: bitmask.Byte(b.Byte(3)), } if f.SessionStatus == SessionStatusNew { network := TargetNetwork(b.Byte(4)) b.SliceFrom(5) addr, port, err := addrParser.ReadAddressPort(nil, b) if err != nil { return nil, newError("failed to parse address and port").Base(err) } switch network { case TargetNetworkTCP: f.Target = net.TCPDestination(addr, port) case TargetNetworkUDP: f.Target = net.UDPDestination(addr, port) default: return nil, newError("unknown network type: ", network) } } return f, nil }